International Journal of Food Engineering via MedWorm.com

Effect of Gluten Powder on the Quality of Fresh Spaghetti Made with Farina

International Journal of Food Engineering — Thu, 09 Feb 2012 12:36:50 +0100

The objective of this study was to improve the quality of fresh spaghetti made from ordinary wheat flour using gluten powder at different levels (0.0, 0.5, 1.5 and 3.0%, w/w, flour basis). The spaghetti dough was evaluated by a Brabender Farinograph. The results indicated that with increasing the gluten level, peak, stability time and consistency of the dough increased. The results of creep test (carried out using a Texture Analyser) showed that with increasing the gluten content, elasticity of the dough increased while its viscosity decreased. Increasing the gluten level reduced the cooking loss and increased the water absorption of the samples cooked in distilled or salted water (2% NaCl). The hardness and the color of the uncooked and cooked spaghettis improved with increasing the glute...

Effects of Fermentation on Nutritional and Functional Properties of Soybean, Maize, and Germinated Sorghum Composite Flour

International Journal of Food Engineering — Thu, 09 Feb 2012 12:36:46 +0100

Sorghum germination resulted in a substantial tannin loss (95.7 %). Proximate composition, titratable acidity, pasting properties, in vitro protein digestibility, and protein solubility were studied post fermentation (Saccharomyces Cerevisiae) of the blended soybean, maize, and germinated sorghum flours. The pH progressively decreased with fermentation time, while titratable acidity increased from 0.029 to 0.118 ml/ml. Crude protein content increased with fermentation (251.7-274.8 mg/g) as a result of a shift in the dry matter composition. In-vitro protein digestibility markedly increased (12 %) as a result of fermentation. Protein solubility curves were above 30% of which highest for both fermented (12 and 24 hours) and unfermented composite flours were at pH 12 (51.77-77.64%) and lowest ...

Optimization of Enzymatic Hydrolysis Conditions for Preparation of Gingko Peptides from Ginkgo Nuts

International Journal of Food Engineering — Tue, 31 Jan 2012 09:13:50 +0100

Ginkgo nuts were used as raw material and peptides were prepared in turn with Neutral protease and Flavourzyme. In single-factor experiments of Neutral protease, conditions of temperature, pH, enzyme concentration and substrate concentration were optimized in term of degree of hydrolysis (DH). Based on the results of single-factor experiments, an orthogonal experiment (L9(3)4) was conducted to optimize the hydrolysis conditions of Neutral protease. The results showed that enzyme concentration, substrate concentration, reaction temperature and initial pH were the main variables that influenced DH. The highest DH was obtained when hydrolysis time, reaction temperature, initial pH, enzyme amount and substrate concentration were 4 h, 45 oC, 7.0, 1.8 mg/mL and 0.02 g/mL, respectively. Subsequen...

The Effect of Microwave Pasteurization on Some Physical and Chemical Characteristics of Milk

International Journal of Food Engineering — Tue, 24 Jan 2012 10:54:54 +0100

In this research, cow’s milk was pasteurized using microwave (MW) or HTST methods and their effects on some milk components were studied. The results showed no differences between some physico-chemical characteristics like protein, fat, acidity, and solubility percentages due to heat treatments with either MW or HTST and the control samples. The contents of six amino acids (aspartic acid, glycine, glutamic acid, histidine, arginine, and lysine in mg/L) and fatty acids (weight percentage) showed no significant differences using either MW or HTST pasteurization method. There were slight but insignificant differences in trans fatty acid and D-amino acid contents in the milk pasteurized with either MW or HTST method. SDS-PAGE and HPLC analysis of milk proteins did not reveal any differences ...

Modeling and Predicting the High Pressure Carbon Dioxide Inactivation of Microorganisms in Foods

International Journal of Food Engineering — Sat, 21 Jan 2012 18:53:14 +0100

Published high pressure carbon dioxide (HPCD) inactivation data of natural microflora in apple juice and Saccharomyces cerevisiae in distilled water were described by the Weibull model. The shape parameter of the Weibull model was assumed to be pressure and temperature independent and could be fixed to reduce the number of parameters of the model from two to one. The rate parameter of the reduced Weibull model can be described in terms of pressure and temperature by use of a second order polynomial function fulfilling a number of constraints. Integrated models (secondary model incorporated into the primary one) produced successful predictions of survival curves for both natural microflora in apple juice and Saccharomyces cerevisiae in distilled water within the interpolation region. (Sourc...

An Investigation on Physical Ageing of β-Lactoglobulin and Implications for Its Storage

International Journal of Food Engineering — Sat, 21 Jan 2012 18:53:10 +0100

Due to the importance of physical ageing in functional properties of the globular protein of β-lactoglobulin as the main protein of whey powder (the by product of cheese manufacturing industry) the possible occurrence of physical ageing in dry powder of β-lactoglobulin with moisture content of 15.9% was studied at different temperatures below and close to the glass transition. Endothermic peaks that corresponded to relaxation enthalpy were observed for a β-lactoglobulin with 4 % moisture. Enthalpy and peak temperature increased on storage of β-lactoglobulin when it was held in the glassy state at different temperatures (20, 40, 60 º C). The general characteristics of the endothermic peaks were similar to those previously reported for synthetic polymers. (Source: International Journal ...

Modeling and Characterization of Blended Guava Pomace and Pulse Powder Based Rice Extrudates

International Journal of Food Engineering — Fri, 20 Jan 2012 02:11:12 +0100

The purpose of the present work was to study the effect of guava pomace and pulse powder incorporation in to rice based extrudates on physical characteristics. Guava pomace collected after juice extraction was dried and milled. It was then added with pulse powder-rice flour blend at different combinations based on Central Composite Rotatable Design (CCRD). The independent variables were moisture content (17 – 21%), temperature (115 – 135°C), screw speed (230 – 270rpm), and varying proportion of rice, pulse and guava pomace. Higher feed moisture content resulted in extrudates with a higher density, lower expansion, higher water absorption index, lower water soluble index, and higher hardness. Higher barrel temperature resulted in reduced density, increased expansion, and water solubi...

Evaluation of Boundary Conditions for CFD Simulation of Liquid Food Thermal Process in Glass Bottles

International Journal of Food Engineering — Thu, 19 Jan 2012 01:35:36 +0100

The growing demand for safer and high-quality food products creates the need for better knowledge of the processes involved in food production. The computational fluid dynamics (CFD) have been widely used to better understand food thermal process, one of the safest and most frequently used methods for food preservation. However, no consistency in mathematical models has been observed, especially on the boundary conditions definition. The present study has evaluated four methodologies for the definition of boundary conditions for heating water in two commercial bottles: (M1) temperature profile of heating water (T∞) and convective heat transfer coefficient (h), (M2) T∞ as boundary condition for the outside package wall, (M3) T∞ as boundary condition for the outside heated liquid edge,...

Using the Mitschka-Briggs-Steffe Method for Evaluation of Cactus Pear Concentrated Pulps Rheological Behavior

International Journal of Food Engineering — Thu, 19 Jan 2012 01:35:34 +0100

The rheological characterization of food is important for efficient product and process design. Although its importance in semi-arid regions, there are only a few studies regarding the rheological properties of cactus pear products in the literature. The present work has used the Mitschka-Briggs-Steffe method for evaluation of the rheological behavior of cactus pear concentrated pulps. The pulps have shown pseudoplastic behavior. The flow behavior index (n) shows a constant value in the evaluated conditions, and its average value was considered in the evaluated temperature and concentration range. The consistency index (k) has shown dependency of concentration and temperature, being well modeled by a modified Arrhenius equation. Thus, the rheological parameters of cactus pear concentrated ...

Mathematical Modelling of the Heat Transfer and Microbial Inactivation During a Meat Pet Food Sterilization in Retortable Pouches

International Journal of Food Engineering — Thu, 19 Jan 2012 01:35:32 +0100

Thermal process is still the most used and safer method for food preservation. Although the mathematical modelling of heat transfer has been used for thermal process evaluation, microbial validation is rarely carried out, and the evaluation of retortable stand up pouch processes were not studied. The present work employed a finite elements analysis model (FEA) for the evaluation of a conductive meat pet food process sterilization in stand up retortable pouches. The results obtained by the model showed good agreement with the experimental values, for both temperature histories and microbial inactivation comparison. The results obtained demonstrate the utility of using mathematical models for describing the heat transfer and microbial inactivation in food thermal process, and reinforce that ...

Functional Characteristics of Extruded Blends of Potato Flakes and Whey Protein Isolate

International Journal of Food Engineering — Tue, 17 Jan 2012 14:12:12 +0100

The purpose of the present study was to explore the effects of feed moisture and the addition of whey protein isolate on some physicochemical properties of the obtained extrudates from potato flakes. Extrudates were produced using a laboratory single-screw extruder. Conditions during extrusion were: screw speed - 200 rpm; compression ratio - 3:1; extruders temperature zones - 120, 150, 160 °C; diameter of the nozzle - 5 mm. With increasing of feed moisture content and protein level, there was a significant rise of density as well as lowering of expansion of extrudates. As the feed moisture content increased from 13 to 20 percent w.w. the water absorption index (WAI) increased and the water solubility index (WSI) decreased. The feed protein level increased the protein content and decreased...

Numerical Simulation of Experimental Freezing Process of Ground Meat Cylinders

International Journal of Food Engineering — Tue, 17 Jan 2012 14:12:09 +0100

The efficient prediction of freezing processes is important for the frozen food industry with the purpose of preserving food quality. A comparison is made between the finite difference and finite volume methods to predict the unsteady 2D temperature distribution for the freezing of three different ground meat cylinders, with variable convective boundary conditions. Experiments were carried out to measure the local heat transfer coefficients as a function of freezing time and location. Time-dependent air temperature conditions caused by thermostat action were included in the analysis. The meat thermophysical properties as density, specific heat, and thermal conductivity are assumed to vary non-linearly with temperature. The experimentally measured time-temperature data were compared with th...

Correlating the Data on the Mechanical Damage to Mung Bean Seeds under Impact Loading

International Journal of Food Engineering — Fri, 13 Jan 2012 02:18:14 +0100

This study evaluated impact damage to the mung bean seeds with moisture contents of 9.54 to 25% wet basis and subject to impact velocities from 10 to 25 m/s using a laboratory impact damage assessment device. The results showed that impact velocity, moisture content, and the interaction effects of these two variables significantly influenced the percentage physical damage in mung ban seeds (p (Source: International Journal of Food Engineering)

Gel Properties of Ribbonfish (Trichiurus haumela) Surimi Gels with Soybean Dietary Fiber Induced by High Pressure and Heating

International Journal of Food Engineering — Fri, 13 Jan 2012 02:18:12 +0100

The effect of soybean dietary fiber in the functional and mechanical properties of restructured products from ribbonfish induced by their different treatments was investigated. Different amount of soybean dietary fiber (0, 10, 20, 30, or 50g/kg) was added at the same time as ice water to maintain similar moisture level in all samples. Then the samples with the same level of soybean dietary fiber were treated by high pressure (300MPa, 10min, P), high pressure followed by cooking (300MPa for 10min, then 90 ℃ for 20min, PC), and cooking after setting (40 ℃ for 30min, then 90 ℃ for 20min, SC), respectively. Results obtained suggest that soybean dietary fiber increased the gel strength of sample gels regardless of the treatments, and improved the texture properties of gels induced by PC a...

Mechanical Damage to Pinto Bean Seeds as Affected by Moisture Content, Impact Velocity and Seed Orientation

International Journal of Food Engineering — Wed, 04 Jan 2012 07:42:51 +0100

The objective of this experiment was evaluate of the impact damage to pinto bean seeds where seed moisture content (9.25, 12.51, 15.01, 17.52, 20.01% wet basis), impact velocity (5.5, 8, 10, 12.5 and 15m/s) and seed orientation (end and side) were independent variables. The study was conducted under laboratory conditions, using an impact damage assessment device. The results showed that impact velocity, moisture content and seed orientation significantly influenced the physical damages of pinto beans at 1% level. Increasing the impact velocity from 5.5 to 15m/s caused an increase in the mean values of damage from 0.39 to 37.30%. With increase the moisture content from 9.25 to 17.52%, the mean values of percentage of damaged beans decreased significantly from 41.24 to 4.27%. However, by a h...

Optimization of Extraction of D-pinitol and Phenolics from Cultivated and Wild Types of Carob Pods Using Response Surface Methodology

International Journal of Food Engineering — Fri, 30 Dec 2011 02:09:20 +0100

The carob pod, an important fruit of the food industry in the production of concentrated syrup, is rich in potentially health-promoting phenolic compounds and sugars. Moreover, one of the important bioactive components of carob is D-pinitol, and it has some beneficial effects on human metabolism. The optimum conditions for extraction of D-pinitol and total phenolic compounds (TPC) from cultivated and wild types of carob pods were determined using response surface methodology (RSM). The Box-Behnken Design (BBD) was used to investigate the effects of three independent variables; extraction temperature (ºC), dilution rate (w/v), and extraction time (h) on the response, D-pinitol and the total phenolic compounds. The optimum extraction conditions obtained using the response optimizer were an ...

Optimized Neural Network for Instant Coffee Classification through an Electronic Nose

International Journal of Food Engineering — Fri, 23 Dec 2011 18:50:30 +0100

Flavor is one of the most important features of food, especially of coffee. The evaluation of this sensory feature is complex yet indispensable in quality control of instant coffees. In this work, an artificial neural network (ANN) was developed for instant coffee classification based on an electronic nose (EN) aroma profile. To this purpose, a hybrid algorithm was developed, containing: bootstrap resample methodology; factorial design and sequential simplex optimization to tune network parameters; an ensemble multilayer perceptron (MLP) trained with backpropagation for coffee classification; and causal index procedure for knowledge extraction from the trained ANN. The produced neural network classifier correctly recognizes 100% of coffees studied. Furthermore, the causal index employment ...

Performance of Artificial Neural Network for Predicting Fermentation Characteristics in Biosurfactant Production by Bacillus subtilis ATCC 6633 using Sugar Cane Molasses

International Journal of Food Engineering — Tue, 13 Dec 2011 10:12:39 +0100

Artificial neural network (ANN) was successfully applied to model fermentation parameters for biosurfactant production by Bacillus subtilis ATCC 6633 using sugar cane molasses. Cell growth and biosurfactant production were monitored along the surface activity of the cell-free broth. Response surface methodology (RSM) as a formal statistical model building system was used for the ANN development. The network predicted biosurfactant concentration was 0.381 g/l which showed almost no differences with the relevant experimental value which obtained according to the RSM arrangement. Furthermore, the ANN surface tension reduction was 30.48 mN/m, which was within 3.24% of the experimental value. Comparisons between RSM and the ANN showed preference of using ANN as complementary to RSM and not as a...

Low Temperature Drying With Air Dehumidified by Zeolite for Food Products: Energy Efficiency Aspect Analysis

International Journal of Food Engineering — Sat, 10 Dec 2011 03:44:22 +0100

Developments in low temperature drying of food products are still an interesting issue; especially with respect to the energy efficiency. This research studies the energy efficiency that can be achieved by a dryer using air which is dehumidified by zeolite. Experimental results are fitted to a dynamic model to find important variables for the drying operation. The results show that ambient air temperature as well as the ratio between air flow for drying and air flow for regeneration, affect the energy efficiency significantly. Relative humidity of used air, and shift time have a minor effect on the dryer performance. From the total work, it can be noted that the dryer efficiency operated at 50-60°C achieves 75 percent, which is attractive for drying of food products. (Source: Internationa...

Adsorption Isotherms for Red Onion Slices Using Empirical and Neural Network Models

International Journal of Food Engineering — Tue, 06 Dec 2011 10:22:44 +0100

Moisture sorption isotherms of red onion slices were determined at 30, 40, 50, and 60°C using the standard gravimetric static method over a range of relative humidity from 0.11 to 0.83. The experimental sorption curves were fitted by seven empirical equations: modified Henderson, modified Chung–Pfost, modified Halsey, modified Oswin, modified Smith, modified BET, and GAB. Also three types of Artificial neural network models: linear, multilayer perceptron, and radial basis function were tested and developed to predict the equilibrium moisture content of onion slices and the selected models were trained by using related algorithms. The modified Oswin model was found acceptable for predicting adsorption moisture isotherms and fitting to the experimental data, based on the coefficient of de...

Comparison of Vacuum Cooling with Conventional Cooling for Purslane

International Journal of Food Engineering — Tue, 06 Dec 2011 10:22:42 +0100

Vacuum cooling technology is a proven technology widely applied on precooling of leafy vegetables, mushrooms, baked goods, fish, sauces, cooked foods, and particulate foods. Vacuum cooling is known as a rapid evaporative cooling technique for moist and porous products. Vacuum cooling has some advantages, such as shortened processing time, extended product shelf life, and improved product quality and safety. The aim of this paper is to apply the vacuum cooling technique to the cooling of purslane and show the pressure effect (for 0.7 kPa, 1 kPa, 1.5 kPa) on the cooling time and temperature decrease. Another purpose of this article is to compare conventional cooling (cooling by refrigerator) with vacuum cooling. It has been seen that purslane can be cooled much more rapidly and efficiently w...

Production of Gallic Acid by Immobilized Aspergillus niger Using Polyurethane Foam as Solid Support

International Journal of Food Engineering — Tue, 06 Dec 2011 10:22:40 +0100

The present study was aimed at finding the optimal conditions for maximum gallic acid production using polyurethane-immobilized Aspergillus niger cells and determining the operational stability of recycled cells for gallic acid production. Maximum gallic acid (142 µg/ml) was produced with 1% tannic acid at 40°C, pH 5.0, with polyurethane foam size of 1.5 cm3 cubes after 48 h under submerged fermentation at 220 rpm, as compared to free cells, which produced 72 µg /ml gallic acid in 72 h at 37°C and pH 5.0. Continuous production of gallic acid by recycling of the immobilized cells resulted in maximum gallic acid production of 199 µg/ml after the fourth cycle, and thereafter remained stable till the seventh cycle and could be continued till the tenth cycle. Pyrogallol, a degradation prod...

Optimization of Enzymatic Hydrolysis of Cucurbitin Using Response Surface Methodology: Improvement of the Functional Properties

International Journal of Food Engineering — Fri, 18 Nov 2011 07:48:27 +0100

Optimization of enzymatic hydrolysis of cucurbitin, extracted from pumpkin (Cucurbita pepo) oil cake with bromelain, was carried out by response surface methodology (RSM). Second-order polynomial model (R2=0.791) has been proposed for the effect of time (t), and enzyme/substrate ratio (E/S) on degree of hydrolysis (DH). Conditions for obtaining maximal value of DH were determined (E/S= 0.0132 (w/w), t= 42 min). Furthermore, according to the regression equation, conditions for production of hydrolysates with target DH values were chosen. Comparison of the functional properties of cucurbitin and its hydrolysates (DH= 10%, 20% and 30%) were carried out. The solubility of the hydrolysates gradually increased with the increase of DH, in pH range of 6–8. The hydrolysate with DH=10% had the bes...

Enhanced Production of Menaquinone 7 via Solid Substrate Fermentation from Bacillus subtilis

International Journal of Food Engineering — Tue, 15 Nov 2011 07:15:44 +0100

Natto, the richest known source of menaquinone 7 (MK7), is traditionally produced via Solid Substrate Fermentation (SSF) by Bacillus subtilis natto on cooked soy beans. In this work we report a threefold increase in MK7 concentration through the use of a mixture of soy protein granules and nixtamalized corn grits. The effects of fermentation processing factors were investigated and optimized in laboratory scale. These factors include initial moisture content, incubation temperature, incubation time, α-amylase pretreatment and solid substrate medium. Response surface methodology (RSM) was used to develop a mathematical model to identify the optimum values of key process variables to increase MK7 concentration; the model was also validated experimentally. The polynomial model fitted the exp...

Comparative Effects of Microwave and Water Bath on the Packing Films of Milk

International Journal of Food Engineering — Sat, 29 Oct 2011 01:46:47 +0100

Milk is heated by microwave or conventional water bath in our daily lives. To investigate the influence of heating modes on food package safety, the present work is designed to compare the changes to packaging materials of milk subjected to microwave treatment and water bath. The mechanical properties of milk package materials were compared, and the migration of harmful substances from the films was analyzed. The results showed that the microwave and water-bath treatments could both influence the mechanical properties of the film. For the heat-sealing strength, the susceptibility of the package materials from different manufacturers was varied. For the tensile strength, the changes were obvious after treatment. Both treatments could induce migration, but the amounts of migrating materials ...

Correlation of Electrical Conductivity and Thermal Properties of Native Starch during Ohmic Heating

International Journal of Food Engineering — Mon, 24 Oct 2011 07:50:58 +0100

Electrical conductivity of starch suspension during ohmic heating was applied to analyze the starch gelatinization process. Native starches from wheat, corn, rice, potato, sweet potato, and pea were prepared on a starch to water ratio of 1:3 (w/w) with adding 0.05 M potassium chloride. A laboratory scale ohmic heating setup was designed to heat the starch suspension from room temperature to 90°C at a controlled heating rate of 10°C/min operating at 50 Hz and 110 V. The results show that starch gelatinization temperatures could be precisely calculated from electrical conductivity of starch suspension during ohmic heating process. The starch gelatinization temperatures based on ohmic heating were comparable to those measured by differential scanning calorimetry (DSC). Highly significant co...

Amino Acid Species and Leaching Characters in Tea (Camellia sinensis) Using Ion Chromatography with Integrated Amperometric Detection

International Journal of Food Engineering — Sat, 01 Oct 2011 01:33:40 +0100

Tea is one of the most popular nonalcoholic beverages consumed in the world and contains a lot of amino acids. By simulating the infusion process of tea according to Chinese customs, amino acid species in tea infusions from three kinds of Chinese tea leaves were determined by ion chromatography with integrated amperometric detection. Furthermore, the relationship between leaching characters of amino acids and time, temperature and number of tea extractions was investigated. Leaching of amino acids was strongly affected by extraction time and temperature. The leaching ability for amino acids by hot water was high, with most of the amino acids left in the tea infusion. The results showed that the major species of amino acids in the tea infusion were arginine, glycine and histidine. According...

Decontamination Efficiency of Slightly Acidic Electrolyzed Water on Fresh-Cut Cucumbers

International Journal of Food Engineering — Fri, 30 Sep 2011 10:00:05 +0100

The efficacy of slightly acidic electrolyzed water (SAEW, 20 mg/l of available chlorine) and sodium hypochlorite solution (NaClO, 120 mg/l of available chlorine) used as potential sanitizers for fresh-cut cucumbers was evaluated. SAEW with a near-neutral pH value (5.0 to 6.5) and lower available chlorine concentration (ACC) had an equivalent or higher efficiency to reduce microbial counts on the cucumbers compared to NaClO solution. A 5-minute treatment of SAEW and NaClO solution significantly reduced the indigenous aerobic bacteria on cucumbers by 1.62 and 1.51 log10 CFU/g, and molds and yeasts by 1.35 and 1.12 log10 CFU/g, respectively (P < 0.05). The reduction of microbial counts on cucumbers by tap water was markedly less than that by SAEW and NaClO solution (P < 0.05). Results indicat...

Measurement of Bed Grain and Air Conditions during Solar Drying of Rice

International Journal of Food Engineering — Wed, 28 Sep 2011 02:08:52 +0100

Experiments on solar drying of rice were conducted in Cambodia in December 2004 using two local rice varieties and traditional methods practiced by farmers. For the whole drying time, the climate conditions—including the wind speed, ambient air temperature and relative humidity, as well as the solar intensity—were regularly monitored, along with the temperature, moisture content and relative humidity of the grain and air at different depths within the drying beds. Two drying treatments per day were extensively monitored. The monitoring showed that all of the processes of solar radiation, convection and evaporation at the surface, and conduction, convection, evaporation and diffusion within the bed are important. (Source: International Journal of Food Engineering)

Effects of Different Solar Drying Methods on Drying Time and Rice Grain Quality

International Journal of Food Engineering — Wed, 28 Sep 2011 02:08:47 +0100

Paddy rice was sun dried in Cambodia in 2004 using a range of methods practiced by local rice farmers. For each treatment in the experiment, a grain sample at about 22% moisture (typical harvest moisture content) was sun dried between 8 a.m. and 4 p.m. During experiments, the grain moisture content was measured at regular intervals. The grain varieties used, bed depths, stirring of the grain, bulk tempering after drying and the drying pads had significant effects on the drying time. Drying was faster when bed depth was reduced, regularly stirred but not shaded or covered and when the drying was carried out on a porous pad. Damage to the dried grain was reduced when the bed was thin, stirred and shaded and when the drying was slow on pads with less air circulation. (Source: International Jo...

Survival of Salmonella typhimurium NRRL E4463 in Sauerkraut during Fermentation

International Journal of Food Engineering — Sat, 24 Sep 2011 11:54:16 +0100

In this research, the survival characteristic of Salmonella typhimurium NRRL E4463 in sauerkraut during fermentation was investigated. Salmonella typhimurium strains were inoculated in sauerkraut, and counts were determined on the 0, 1st, 2nd, 4th, 6th and 7th days of the fermentation. It was observed that the initial count of Salmonella typhimurium was 6.61 log cfu/g on the inoculation day, and it declined to (Source: International Journal of Food Engineering)

Development of Hot-Air Dried Cut Persimmon

International Journal of Food Engineering — Fri, 23 Sep 2011 07:50:26 +0100

In this work the authors have studied the effect of hot-air drying with or without a previous osmotic dehydration pretreatment to produce dried cut persimmon with a different geometry (slices and sectors). A kinetic study has been carried out analysing mass variation, colour and texture changes in samples. Two sensory analyses were also performed considering drying time and geometry. Furthermore, the influence of 35 days of storage on optical and mechanical properties was also determined. The results obtained showed that geometry did not affect the parameters analyzed. According to the results of the kinetic study, the selected drying times were 8 and 12 hours. Osmotic pretreatment does not imply improvements in the final product. Judges preferred slices dried for 8 hours without osmotic p...

Effects of Lyophilization and Use of Probiotics on Donkey’s Milk Nutritional Characteristics

International Journal of Food Engineering — Thu, 22 Sep 2011 14:25:10 +0100

This study investigated the effects of the lyophilization treatment on donkey’s milk nutritional characteristics, and the results were compared with those obtained on fresh and frozen milk. Nutritional properties of lyophilized donkey’s milk remained basically unchanged compared with fresh milk. Two different probiotic strains were added to lyophilized donkey’s milk, and their viability was evaluated after milk reconstitution. The results obtained confirmed the possibility of producing a probiotic infant formula with beneficial properties using donkey’s milk as raw material. (Source: International Journal of Food Engineering)

Some Quality Aspects of Persimmon Jam Manufactured by Osmotic Dehydration without Thermal Treatment

International Journal of Food Engineering — Sun, 18 Sep 2011 14:41:09 +0100

In conclusion, this method of preparing jam from persimmons could increase the commercial possibilities of this fruit, using refrigerated storage. (Source: International Journal of Food Engineering)

Effect of Variable Sugar Concentrations on Glycogen and Ethanol Content in Saccharomyces sp.

International Journal of Food Engineering — Wed, 14 Sep 2011 15:35:02 +0100

Saccharomyces cerevisiae (MTCC-12) maintains two pools of glycogen, one soluble and the other cell wall bound insoluble glycogen. Effect of variable concentrations of sugar on the insoluble pool of glycogen linked to wall β-glucan component was found to be more significant than that observed for soluble pool of glycogen. The study revealed that cells exhibit exponential increase in the amount of insoluble glycogen with corresponding increase in sugar concentration from 2-10 % (w/v). Ethanol content as well as concentration of insoluble glycogen in yeast cells, which were grown in sucrose medium, shows higher values than in glucose medium. Parallel increase in glycogen and ethanol content indicates their correlation with each other. Exponential increase in insoluble glycogen content serves...

Effect of Infrared Drying on Drying Kinetics, Color, Total Phenols and Water and Oil Holding Capacities of Orange (Citrus Sinensis) Peel and Leaves

International Journal of Food Engineering — Wed, 14 Sep 2011 00:52:28 +0100

The aims of this work were to determine the desorption isotherms of “Maltaise” orange peel and leaves and to investigate the effect of the infrared drying on the drying kinetics and on the physical and functional properties. The moisture desorption curves showed a sigmoïd shape (type II on the BET classification). GAB was found to be the best model for describing the desorption curves. The infrared drying rate increased, with temperature increasing at the same moisture ratio. High drying temperatures preserved initial color parameter values of “Maltaise” orange peels (from 21.893 ± 0.629 to 24.793 ± 0.525, from 37.973 ± 0.941 to 45.44 ± 0.390 and from 45.350 ± 1.077 to 50.439 ± 0.740 for a*, b* and C, respectively) and leaves (from -5.98 ± 1.651 to -5.276 ± 0.342, from 10....

Modeling of Respiration Rate of Capsicum at Various Temperatures

International Journal of Food Engineering — Mon, 29 Aug 2011 15:25:50 +0100

Respiration rate is critical in the design of modified atmosphere/control atmosphere (MA / CA) storage system. Success of these systems is based on correctly mapping of respiration process. Respiration rate of capsicum was studied at 5, 10, 15, 20, and 25 °C using closed system respiration method. Respiration was found to be influenced by temperature and followed Arrhenius law. The generated data were used to develop different types of models, one based on principle of enzyme kinetics, and two based on regression analysis. All developed models were validated at 13°C. The obtained results showed that developed models were valid and represented the respiration process. Model based on principle of enzyme kinetics with Arrhenius type and four-parameter second-order polynomial model showed be...

Influence of Hydrocolloid Concentration, Salinity and Citric Acid Addition on Heat Transfer in the Ohmic Heating Process

International Journal of Food Engineering — Fri, 26 Aug 2011 01:36:45 +0100

In this article, the effects of Ohmic heating process conditions on electrical conductivity and heat transfer were investigated. In order to study the Ohmic heating process, various hydrocolloid solutions containing starch in water with concentrations of 4–8% in the static cells were used. Temperature increments increased electrical conductivity of the solution, linearly. The concentration of dispersed solid particles in the solution caused a progressive trend in time-temperature curve for hydrocolloid solutions (with concentrations of 4, 5.5 and 8%) without electrolytes. The electrical conductivity was raised by increasing temperatures. In order to consider the salinity impact on electrical conductivity and the heating rate, sodium chloride (with concentrations of 1–0.25%) was added t...

Effects of Ultrahigh Pressure Extraction Conditions on Yields and Antioxidant Activities of Flavonoid from Laoying Tea

International Journal of Food Engineering — Wed, 24 Aug 2011 01:36:52 +0100

Ultrahigh pressure extraction technique was employed to extract flavonoids from Laoying tea. Orthogonal design was applied to evaluate the effects of four independent factors (extraction pressure, pressure holding time, ethanol concentration, and solvent to sample ratio) on the yields of total flavonoids. Subsequently, the antioxidant activities of ultrahigh pressure extracts and conventional water bath extracts were analyzed by employing two antioxidant model systems including 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity and reducing power. Results showed that the optimal conditions of UHPE were obtained at extraction pressure 400 MPa, pressure holding time 10 min, ethanol concentration 70% (V/V), and solvent to sample ratio 50:1 mL/g, and under such conditions, t...

Poultry By-Products and Enzymatic Hydrolysis: Optimization by Response Surface Methodology Using Alcalase® 2.4L

International Journal of Food Engineering — Wed, 24 Aug 2011 01:36:48 +0100

The objective of this study was to determine the optimum conditions for production of a poultry by-product hydrolysate by Alcalase® 2.4L. Response surface methodology was conducted to ascertain this aim. The effects of enzyme/substrate ratio (Anson unit/g protein), time (minute) and temperature (°C) were determined. The responses included the degree of hydrolysis (%) and nitrogen recovery (%) at pH 8.5. The model showed a good fit, since the R2 = 0.981 for DH and the R2 = 0.968 for nitrogen recovery indicated that 98.1% and 96.8% of the variability within the range of values studied could be explained by the models. Furthermore, lack of fit of the models was not significant (p (Source: International Journal of Food Engineering)

Ice Cream Powder Production and Investigation of Its Rheological and Organoleptic Properties

International Journal of Food Engineering — Tue, 23 Aug 2011 00:42:51 +0100

A basic formulation (50 g sucrose + 47.5 g milk powder + 1.5 g cocoa powder) was mixed thoroughly with various proportions of xanthan, sodium alginate, tragacanth gum and carrageenan gums to make fifteen desired formulations of ice cream powder. The ice cream powders and water were poured into the ice cream maker machine in proportions of one to one (w/w) and ice creams were prepared and compared. Melting time, rheological and organoleptic tests on the produced ice creams were performed and the results showed that the maximum viscosity and melting time belonged to the number 7 and 14 samples, having tragacanth and carrageenan in their formulations, respectively. Overall, acceptability of the samples 1, 7, 8 and 14 was the highest. Using mixed combinations of hydrocolloids in ice cream powd...

Modeling Mass Transfer Kinetics and Mass Diffusivity During Osmotic Dehydration of Blanched Carrots

International Journal of Food Engineering — Fri, 19 Aug 2011 06:13:56 +0100

Osmotic dehydration of 3.5 mm thick blanched carrot slices was carried out in order to study the effect of sucrose concentration, solution temperature and time on mass transfer kinetics and mass diffusivity. The experiments were conducted at the combinations of four sucrose concentration (30, 40, 50 and 60% w/w) and four solution temperatures (25, 37.5, 50 and 62.5°C). At each combination, nine time intervals (10, 20, 30, 40, 50, 60, 80, 100 and 120 min) were selected to determine the moisture loss and sucrose gain. Sample-to-solution ratio was kept 1:10 w/w through all the experiments. It was found that sucrose concentration and time of osmosis increased mass transfer whereas; solution temperature showed effect only on solid gain. Azuara’s models were used to determine the mass transfe...

Comparative Study on Drying of Selected Marine Products: Bombay Duck (Herpodon nehereus) and Prawn (Penaeus indicus)

International Journal of Food Engineering — Fri, 19 Aug 2011 03:11:59 +0100

A study on drying of two types of fish, viz., Bombay duck and Prawn, using the open sun, a solar cabinet, hot air and freeze drying was carried out. The fish were dried to 5–6% moisture content. The drying rates were calculated and drying data were fitted to the Page model, and on the basis of R2 and RMSE values it was found that the Page model describes satisfactorily the drying behavior of Bombay duck and Prawn. Also, effective moisture diffusivity values were calculated during fish drying by different methods. The values of the average effective moisture diffusivity of Bombay duck and Prawn were in the range of 1.01 × 10-9 to 1.51 × 10-9 m2 s-1and 0.21 × 10-9 to 0.31 × 10-9 m2 s-1, respectively. Freeze drying was found to provide the best quality of dehydrated product, which was a...

Solubility of Palm Oil Components in Supercritical Carbon Dioxide

International Journal of Food Engineering — Fri, 19 Aug 2011 03:11:53 +0100

The effects of operating pressures and temperatures on the solubilities of acylglycerols and free fatty acids (FFA) of palm oil (Elaeis guineensis) in supercritical carbon dioxide (SC-CO2) were determined using a dynamic (flow-through) supercritical fluid extraction system. The solubility of palm oil was also investigated. The experiments were carried out in a 3 X 3 factorial design with three equally spaced pressures (14, 22 and 30 MPa) and three equally spaced temperatures (40, 60 and 80°C). The solubilities (mg/g CO2) of acylglycerols and FFA followed this order: TAG > FFA > DAG > MAG for high pressure. However, highest solubility of FFA was observed at low pressure. The results showed that the solubility of palm oil in SC-CO2 was in the range of 0.1751 ± 0.0007 to 6.60 ± 0.03 mg/g f...

Twin-Screw Extrusion of Pre-Germinated Brown Rice: Physicochemical Properties and γ-Aminobutyric Acid Content (GABA) of Extruded Snacks

International Journal of Food Engineering — Thu, 18 Aug 2011 15:14:22 +0100

Pre-germinated brown rice (PGBR) from non-glutinous (KDML 105) and glutinous (RD 10) varieties was produced by a soaking method in cool water at 25°C for 48 h. After germination, increased crude fiber, reducing sugar (P ≤ 0.05) and the γ-aminobutyric acid (GABA) content (P ≤ 0.01) and decreased fat were observed. The extrusion was carried out in a twin-screw extruder by a central composite design (CCD) which studied the effect of feed moisture (15.6-22.3%), screw speed (264-434 rpm) and pre-germinated glutinous brown rice flour level (0-63.6%) on the physicochemical properties of extruded snacks (expansion ratio, density, hardness, brittleness, water absorption index (WAI), water solubility index (WSI)) and GABA content. Second-order polynomial models were computed and used to genera...

Shelf Life Prediction Modeling of Vacuum-Packaged Scallops on the Kinetics of Total Volatile Base Nitrogen

International Journal of Food Engineering — Thu, 18 Aug 2011 01:32:44 +0100

Argopecten irradians is one of the cultivated species of seafood in China. Frozen, dried, and vacuum-packaged scallops are the main processed forms of this species. Due to their high moisture content, vacuum-packaged scallops are perishable during storage; thus, accurately predicting shelf life according to the storage environment is particularly important for the seafood industry. Vacuum-packaged instant scallops stored at 20, 25, 30, 35, and 40 °C were used in the current study. Total volatile base nitrogen (TVB-N), pH, water activity, color, hardness, and microbiological composition were ascertained during storage. Based on the 10-point hedonic scale, the shelf lives of instant scallops stored at 20, 25, 30, 35, and 40 °C were 96, 78, 60, 42, and 32 days, respectively. Using the Arrhe...

Numerical Simulation of Packed Liquid Food Thermal Process Using Computational Fluid Dynamics (CFD)

International Journal of Food Engineering — Wed, 17 Aug 2011 01:37:14 +0100

Thermal processing is one of the safest and most used methods of food preservation. Although the computational fluid dynamics (CFD) has been used by several authors for liquid food thermal processing evaluation, just a few studies have compared the data obtained by CFD with experiments. The present work evaluated a liquid model food pasteurization in two commercial bottles using CFD. The model validation was carried out by comparing the obtained thermal profile with experimental data. The fluid behavior during heating and cooling was detailed. The data obtained using CFD described well the experimental processing, which suggest the possibility of using CFD for temperature profile evaluation in thermal processing of packaged convective foods. (Source: International Journal of Food Engineeri...

Determining the Convective Heat Transfer Coefficient (h) in Thermal Process of Foods

International Journal of Food Engineering — Fri, 12 Aug 2011 22:53:14 +0100

Thermal processing is the most important and utilized method for food preservation, being those carried out with the food inside the package the most appropriated for safety consumption guarantee. During processing, the packaged food is surrounded by a heat transfer medium, in general a fluid as water, steam, air or its mixtures. Therefore, the definition of the convective heat transfer coefficient (h) is important for several process studies, although the available data is scarce, especially in food thermal processes. Although there is several methods for determining the h values, the non-regular food geometries and transient characteristics of thermal processes, makes difficult using most of the methods. This work aimed to describe an appropriated method to determining the convective hea...

Experimental Study and Modeling NaCl Mass Transfer during Feta Cheese Ripening

International Journal of Food Engineering — Thu, 11 Aug 2011 01:28:43 +0100

The NaCl spatial distribution and model development during two ripening stages of Feta cheese were studied in the paper. The results showed that NaCl spatial distribution of 12 locations for each layer had no significant differences (P>0.05) during the whole ripening, while the values of NaCl spatial distribution of each layer had significant differences (p0.05) during stage II (from day 20 to day 60). Based on statistical analysis of experimental data, the power models with three sets of parameters for three layers were developed during stage I, and a sigmoid model was developed for the entire cheese during stage II. The R2 of the four models were 0.975, 0.978, 0.991 and 0.997, respectively. The models had a good fit of experimental values and can be used to predict the spatial distributi...

Microwave Assisted Multi-Stage Countercurrent Extraction of Dihydromyricetin from Ampelopsis grossedentataa

International Journal of Food Engineering — Thu, 11 Aug 2011 01:28:39 +0100

A novel microwave assisted multi-stage countercurrent extraction (MAMCE) technique was developed for the extraction of dihydromyricetin from Chinese rattan tea, Ampelopsis grossedentata. The technique combined the advantages of microwave heating and dynamic multi-stage countercurrent extraction and achieved marked improvement in extraction efficiency over microwave assisted batch extraction. Analysis of dihydromyricetin concentrations in the solvent and matrix throughout the extraction process showed that by dividing the extraction into multiple stages and exchanging of solvents between stages, steady and substantial concentration gradients were established between the matrix and solvent, thus enabling the achievement of high extraction efficiency. The yield of dihydromyricetin was signifi...

Organoleptic Quality, Minerals, Proteins and Amino Acids from Two Tunisian Commercial Pomegranate Fruits

International Journal of Food Engineering — Fri, 05 Aug 2011 14:37:50 +0100

Chemicals from fresh pomegranates were established. Total sugar of juice extracts are mainly fructose (ca. 7.27 g/100 ml) and glucose (ca. 8.11 g/100 ml). Pulp minerals, expressed as mg/100g are potassium (351.26), magnesium (10.02), calcium (9.26), sodium (7.25), iron (0.15), Zinc (0.10), copper (0.08) and manganese (0.04). Juice proteins are about 7.95 g/l and dry pulp proteins are 24% on a dry-weight basis DW (Kjeldhal assays). Seed proteins are ca. 16.87% DW. Globulins (62.4 mg/g DW) and albumins (54.12 mg/g DW) are the major storage protein fractions, followed by glutelins (33.2 mg/g DW) and prolamins (18.08 mg/g DW). Seed total amino acid content is 14.45 g/100 g DW. Seeds are rich in Glu, Arg, Asp, Leu and Gly amino acids. Essential amino acids average 33.54% of total amino acid. Es...

Measurement of Flavor Absorption from Soft Drinks into PET Bottle by Headspace Solid Phase Microextraction-Gas Chromatography

International Journal of Food Engineering — Wed, 03 Aug 2011 02:33:03 +0100

Absorption of flavors into packaging is of great importance in the food industry because of the final quality needs of the product. In the present study one-sided exposure of D-limone, α-Pinene and myrcene from three types of carbonated drinks into PET bottles was studied at different test temperatures (4, 25 and 40°C). Headspace solid-phase microexraction was used as a technique for extracting the absorbed flavors from PET and the analysis performed by gas chromatography coupled with FID detector. The results showed that the absorption level of flavors is dependent on the structure and initial concentration of the flavors, media type and storage temperature. The flavors stored at 4°C showed higher consistency in the media, but the absorption rate of flavors enhanced with increasing tem...

Application of High-Voltage Electrostatic Equipment to Ethylene Removal

International Journal of Food Engineering — Wed, 03 Aug 2011 02:33:00 +0100

Ethylene is hazardous to the shelf life of fruits and vegetables. To extend shelf life, the accumulation of ethylene should be prevented. High-voltage electrostatic fields have been found to contribute to the removal of ethylene. To develop high-voltage electrostatic equipment for a storage room, the effects of electrode shape, initial ethylene concentration (IEC), and electrode voltage (EV) on high-voltage electrostatic equipment performance were studied. The ethylene removal rate of the needle–needle electrode was significantly higher than that of the needle–plate electrode. When the EV was -17 KV and the IEC was 200 ppm, ethylene in the gases of the exit-tube could not be detected after 3–5 s. A mathematical model for the removal efficiency, IEC, and EV was established. The result...

Kaempferol Extraction from Cuscuta reflexa using Supercritical Carbon Dioxide and Separation of Kaempferol from the Extracts

International Journal of Food Engineering — Wed, 03 Aug 2011 02:32:54 +0100

Kaempferol, a strong antioxidant, was extracted from Cuscuta reflexa (a medicinal plant) using supercritical CO2 and separated using thin-layer chromatography, column chromatography and HPLC analysis. A rotatable central composite design was used to determine the influence of process variables and arrive at optimal processing conditions in the supercritical CO2 extraction process of kaempferol. The kaempferol yield was effectively modelled as a function of the independent variables (temperature, time and pressure). The kaempferol yield increased with the increasing of temperature and time and decreasing of pressure of the supercritical CO2 extraction process. The predicted kaempferol yield at the optimum point was 52.92 µg/g and the optimum conditions were 50.7°C for 132.6 min and 15.9 M...

Microwave Vacuum Drying of Shredded Carrots and Its Nutritional Evaluation

International Journal of Food Engineering — Tue, 19 Jul 2011 03:54:37 +0100

Microwave vacuum drying of shredded carrots to obtain highly nutritious carrot powder with β-carotene retention above 87% and practically zero solid losses is discussed. Response surface methodology has been used to optimize the drying parameters for shredded carrots. The experiments were carried out to investigate the combined effects of microwave power, vacuum chamber pressure and sample thickness on β-carotene retention. Shredded carrot powder was analyzed for colour retention, glucose and total protein retention, water activity, drying time and sensory responses. A model for the retention of β-carotene was established. A microwave input of 200 W and a pressure of 10 kPa, for a sample thickness of 7.1 mm, were determined to be the optimum conditions for dehydration. The drying data w...

Numerical and Experimental Study on Temperature Crossover in Shell and Tube Heat Exchangers

International Journal of Food Engineering — Fri, 01 Jul 2011 02:33:15 +0100

Experimental and numerical studies were conducted to investigate the heat transfer characteristics of five shell and tube heat exchangers (STHXs) with ratio of the length to width (L/W) at the range of 1.85 to 9.23. Temperature crossover in counter flow STHXs is meaningful in food processing industry. The relationship between temperature crossover and L/W is proposed for the first time. Both the experimental and numerical results show that temperature crossover can be achieved in STHXs with L/W≥4.62 and can’t be achieved any more in STHXs with L/W≤3.08. The results also indicate that heat transfer performance decreases with L/W decreasing. The inherent reason of this phenomenon is analyzed by computational fluid dynamics method. (Source: International Journal of Food Engineering)

Effect of Fermentation on Chemical Composition and Nutritional Quality of Extruded and Fermented Soya Products

International Journal of Food Engineering — Fri, 01 Jul 2011 02:19:15 +0100

The effect of fermentation on chemical composition, amino acid profile and protein digestibility of extruded soya protein products was investigated. The soya protein products (low moisture extruded soya product, medium moisture extruded soya product, high moisture extruded soya product, soya meal and soya kernel) were fermented with Bacillus natto from small and large brands of soya bean cultivar. The protein content (%) ranged from 38.20 to 62.98 with the highest content in the high moisture extruded protein product fermented with Bacillus natto from large brand of soya bean cultivar. Contents of carbohydrates ranged from 14.77 to 29.08 while those of crude fibre, fat and ash were generally low. Fermentation improved protein digestibility in the raw soya meal and kernel than in the unferm...

Color Based Classification for Berries of Japanese Blue Honeysuckle

International Journal of Food Engineering — Fri, 01 Jul 2011 02:19:12 +0100

Japanese blue honeysuckle (Lonicera caerulea L. var. emphyllocalyx Nakai) is a unique form of edible honeysuckle that has exceptionally tasty berries. Visual characteristics of the berry such as the color of the skin and the presence of defects are the most decisive factors in determining its quality. An image analysis based methodology for classifying the berries under uncontrolled outside lighting conditions was developed. A color sheet with hue value around 29° was determined as the background to support the berries whose hue values were found near 212°. With the thresholding level computed by Otsu’s algorithm in the red channel, berries were segmented from the background successfully. Three parameters, average and standard deviation of hue component and average of saturation compon...

Thermal Inactivation of Alicyclobacillus acidoterrestris in a Model Food

International Journal of Food Engineering — Fri, 24 Jun 2011 05:49:08 +0100

Thermal process is among the safer and most used food preservation technique. The utilization of model foods in thermal processes studies has several advantages, and the determination of microorganisms thermal inactivation kinetics in model foods is extremely interesting for studying thermal processes and heat transfer. This work has determined the thermal inactivation kinetics of Alicyclobacillus acidoterretris in a liquid model food, thus providing subsidies for thermal process studies and design. The A. acidoterretris thermal inactivation was determined through the three-neck flask method, and was well described according to a first order kinetics. The D85°C, D88°C, D92°C and D95°C values were 105.4 min, 2.75 min, 7.0 min and 2.3 min, respectively. The observed z-value was 6.1°C. D...

Heat Transfer Studies in Coiled Agitated Vessel with Varying Heat Input

International Journal of Food Engineering — Thu, 23 Jun 2011 02:45:29 +0100

Heat transfer studies in a coiled agitated vessel with varying heat input is presented using two agitators namely propeller and disk turbine. Heat transfer rate increases with agitator speed for both the agitators for a given heat input. The heat transfer coefficient also increases with heat input for a given agitator speed for turbine agitator for all the heat inputs, whereas for propeller it is increasing up to a certain value and then decreases. The heat transfer coefficient (heat transfer rate) for turbine agitator is higher than that for propeller for all heat inputs. Empirical correlations separately were formed for each agitator and found to fit the experimental values within range of ±15% for both the agitators. (Source: International Journal of Food Engineering)

Browning Reaction Kinetics of High Hydrostatic Pressure-Treated Peach Puree during Storage

International Journal of Food Engineering — Fri, 17 Jun 2011 07:17:52 +0100

Kinetics of browning color development, described as browning index (BI), of peach puree subjected to high hydrostatic pressure (HHP) treatments (400, 500, and 600 MPa/1 and 3 min) during 6 weeks of storage at 4 and 20°C were investigated. This research was conducted to modify the use of pressure scale instead of temperature scale in calculating the kinetic parameters of BI values in peach puree samples. The increase in BI values followed the zero-order kinetic model. The highest activation energy (Ea) was experienced with HHP treatment (400, 500, and 600 MPa/3 min) of peach puree samples stored at 4°C. (Source: International Journal of Food Engineering)

Performance Evaluation of a Centrifugal Peeling System for Pistachio Nuts

International Journal of Food Engineering — Tue, 14 Jun 2011 22:46:49 +0100

In this paper, performance evaluation of the centrifugal peeling system for pistachio nuts was studied as a function of moisture content (in five levels: 4.10, 10.50, 28.50 and 36.10 % d.b) and peripheral speed of separate rotating circular base – plate (in four levels: 35, 40, 45 and 50 m/s) in a factorial design based on completely randomized block. The overall performance was expressed in terms of peeling efficiency and breakage percent. Peeling efficiency and breakage increased with (i) increase in peripheral speed (ii) decrease in the pistachio moisture content. The results of an optimization technique revealed that the best peeling performance could be obtained if the machine is operated at peripheral speed of 50 m/s and moisture content of 4.10 % d.b. Under these conditions, the v...

Optimization of the Fermentation Conditions for 1-Deoxynojirimycin Production by Streptomyces lawendulae Applying the Response Surface Methodology

International Journal of Food Engineering — Tue, 14 Jun 2011 02:46:58 +0100

Moranoline (1-Deoxynojirimycin, DNJ) is a piperidine alkaloid, and shows high inhibit activities to glucoamylase and α-glucosidase. One DNJ high-yield strain of Streptomyces lawendulae was obtained after isolated form soil and mutated with the ultra violet (UV) and ethyl sulfate (DES), which named as TB-412, and can produce DNJ with 35.925 mg/L. Response surface methodology (RSM) was applied to optimize the parameters of DNJ yield from S. lawendulae TB-412. The effects of independent variables of fermentation, including time, temperature, initial pH and the soluble starch content were investigated. The statistical analysis showed that the fermentation time, pH and the soluble starch content, and the quadratics of time, temperature, pH and the soluble starch content, as well as the interac...

Extraction and Partial Characterisation of Hydrocolloid Gums from Some African Legumes

International Journal of Food Engineering — Tue, 14 Jun 2011 02:46:53 +0100

In an attempt to understand the potential valorisation of local African legumes, hydrocolloids of five legumes (Corchorus olithorus, Triumfetta cordifolia, Cerathoteca sesamoides, Adansona digitata, and Bridelia thermifolia) were extracted and characterised as polysaccharides. All the gum extracted were rich in galactose residue (31-62 percent), suggesting a galactan backbone for the polysaccharides structure. The other sugar residues of the polysaccharides were arabinose (22-30 percent) in T. cordifolia and B. thermifolia, glucose (22-36 percent) in B. thermofolia, A. digitata and C. olithorus, and mannose (32.9 percent) in C. sesamoides. The intrinsic viscosity measurements showed that gums from T. cordifolia, B. thermifolia, C sesamoides and C. olithorus are high molecular weight polyme...

Study of the Encapsulation Efficiency and Controlled Release Property of Whey Protein Isolate—Polysaccharide Complexes in W1/O/W2 Double Emulsions

International Journal of Food Engineering — Wed, 08 Jun 2011 15:02:50 +0100

The complexes of whey protein isolate (WPI) with guar gum (GG) or gum arabic (GA) were used to prepare water-oil-water double emulsions. Lipid-soluble vitamin E (VE) and water-soluble vitamin B2 (VB2) were encapsulated together in these two systems. The abilities of these complexes to control the release rates were compared. When the ratio of WPI/polysaccharides increased from 5:0.1 to 5:0.5, the encapsulation efficiency (EE) of VE increased from 73 to 88 percent, and EEVB2 from 61 to 68 percent in WPI-GG system; whereas only minor changes were in both EEVE and EEVB2 in WPI-GA system. In the controlled release study, WPI-GG complexes showed better resistance to the attack of the enzymes than WPI-GA complexes did. These phenomena were attributed to the formation of compact aggregates promot...

Moisture Sorption Isotherms and Thermodynamic Properties of Carrot

International Journal of Food Engineering — Wed, 08 Jun 2011 15:02:44 +0100

The water sorption isotherms of carrot were determined at five different temperatures (at 10, 20, 30, 40 and 50ºC) within wide ranges of moisture content (1.3-78.4 kg water /100 kg dry matter) and water activities (0.165-0.907) by using a standardized conductivity thermohygrometer. The sorption isotherms exhibited the type III behaviour, thus, an increase in temperature promoted a decrease in water activity. The GAB, Halsey, Henderson, Iglesias & Chirife and Oswin models were tested to fit the experimental data by using nonlinear regression analysis. The GAB and Henderson models satisfactorily described the sorption isotherms (mean relative error < 5.6%). The net isosteric heat of sorption (Qstn) and the differential entropy (Sd), estimated as functions of the moisture content, decreased ...

Impact of Fruit Ripeness on Physicochemical Properties and Convective Drying Characteristics of Kent Mango (Mangifera indica L. cv. ‘Kent’)

International Journal of Food Engineering — Thu, 26 May 2011 07:18:20 +0100

Impact of ripeness on drying characteristics of mango was studied by considering different zones on the fruit. For each zone, ripeness was estimated by total soluble solids/acidity ratio, colour and texture of fruit flesh. For each state of ripeness, drying curves and time-temperature curves were established both in forced and natural convection. Mass diffusivity (estimated by considering two diffusion regions), thermal diffusivity and drying rates were deduced from these drying curves by considering product shrinkage. Results showed that the time required to reduce moisture content to any given level depended on the ripeness state, being highest for unripe samples and lowest for ripe samples. At each drying moment, temperature of ripe sample was higher than that of unripe sample. Mass dif...

Optimizing Machine Vision Based Applications in Agricultural Products by Artificial Neural Network

International Journal of Food Engineering — Thu, 19 May 2011 00:08:38 +0100

In this study, optimization of ANNs for machine vision based applications for better prediction accuracy has been conducted using soybean weighing as an example. Neural network systems consisting of a varying number of neurons trained under dissimilar algorithms were compared in determining the weights of soybeans based on the correlation of weight to features extracted from one- and two-direction images. Results show that imaging from the side of a soybean produces superior data to that of top-down images, and that with a properly trained neural network, weight predictions could be accurate up to a relative error of less than three percent. Furthermore, the continuous dependence of weight to features of the soybean suggested use of a training batch consisting of uniformly distributed weig...

Recent Methods and Techniques of External Grading Systems for Agricultural Crops Quality Inspection - Review

International Journal of Food Engineering — Wed, 18 May 2011 22:25:19 +0100

In recent years, due to increasing necessity and the rise in agricultural production worldwide, an efficient, uncomplicated and precise classification mechanism of agricultural crops is indeed an important endeavor for high quality products. This paper reviews the recent techniques and features of external grading systems for the non-destructive operation and performance of automated quality verification systems for agricultural products. The grading systems utilize highly technical engineering designs and image processing techniques to convey information and grade the products. The most common methods and techniques involved in the grading system’s external inspection stages such as color, size, shape and texture are highlighted. (Source: International Journal of Food Engineering)

Modeling the Fracture Resistance of Sunflower Seed and Its Kernel as a Function of Moisture Content, Variety, Size and Loading Orientation

International Journal of Food Engineering — Wed, 18 May 2011 22:25:15 +0100

The aim of this work was to develop a mathematical model describing the evolution of rupture force, absorbed energy and deformation at rupture point. The models exploit the theory of the mechanical behavior of sunflower seeds and its kernel with moisture content, variety, size and loading orientation. The proposed models have been tested on three common Iranian varieties of sunflower seeds and their kernels namely Azargol, Shahroodi and Fandoghi. The results showed that rupture forces for both sunflower seed and kernel decreased with increasing moisture content, while in both loading orientations and for all varieties and size categories, the absorbed energy and deformation at rupture point increased as moisture content increased. The required compressive forces in both orientations, to in...

Characterisation of Potato Slices During Drying: Density, Shrinkage, and Thermodynamic of Sorption

International Journal of Food Engineering — Sat, 14 May 2011 01:57:38 +0100

In this study, we are interested in a thermo-physic characterisation during hot air drying of one food product: the potato. The drying kinetics of potato slices are determined at three temperatures and three air velocities. The evolution of the density and the material shrinkage are determined and commented. We finish with the equilibrium moisture relations for the product. From experimental data, we have modeled the desorption isotherms using the GAB model. From the results, we notice that this model perfectly describes the measures with correlation factors superior to 97%. A thermodynamic analysis of isotherms has been made: the heat of sorption is calculated; the entropy of sorption has also been determined and has been commented. (Source: International Journal of Food Engineering)

Effects of Pre-Treatments and Air Drying Temperatures on Colour and Antioxidant Properties of Gac Fruit Powder

International Journal of Food Engineering — Thu, 12 May 2011 08:46:41 +0100

Gac fruit contains extraordinarily high levels of carotenoids that are well-known as strong antioxidants with an attractive yellow-orange-red colour. The aim of this study was to investigate the effects of different pre-treatments and air drying temperatures on colour characteristics, total carotenoid content (TCC) and total antioxidant activity (TAA) of resultant Gac fruit powder. Results showed that pre-soaking in solutions of ascorbic acid or bisulfite prior to air drying at low temperature of 40°C was effective in preserving TCC and TAA. Loss of TCC and TAA increased as drying temperatures increased (50, 60, 70, and 80°C). Moreover, the colour characteristics of Gac powder, such as chroma and hue angle, were not significantly affected by pre-treatments and air drying temperatures. Th...

Influence of Microwave Osmotic Dehydration Pre-Treatment on the Second Stage of Air-Drying Kinetics of Apples

International Journal of Food Engineering — Wed, 11 May 2011 05:11:17 +0100

The effect of microwave-osmotic dehydration pre-treatment under continuous flow medium spray (MWODS) conditions on the second stage air-drying kinetics of apple (Red Gala) cylinders was evaluated. MWODS pre-treatment was carried out using a response surface methodology involving 5-levels of sucrose concentration (33-66.8°B), temperature (33-66.8°C) and contact time (5-55 min). Drying time and coefficient of moisture diffusion (Dm) and coefficient of moisture infusion (Im) during rehydration were evaluated as responses and the results were compared with their air-dried (AD) (worst scenario) and freeze-dried (FD) (best scenario) counterparts without the osmotic treatments. The diffusion and infusion coefficients were based on the solution of Fick's diffusion model. Empirical models develop...

Microencapsulation of Ferrous Fumarate for the Production of Salt Double Fortified with Iron and Iodine

International Journal of Food Engineering — Tue, 26 Apr 2011 01:22:52 +0100

This study evaluates the creation and use of this system, producing engineered iron premixes for integration into coarse iodized salt. Bioavailable ferrous fumarate powders were encapsulated via spray-drying to produce particles which are too small to be detected visually ( (Source: International Journal of Food Engineering)

Development of a Garlic Clove Peeler for Small Scale Industry

International Journal of Food Engineering — Fri, 22 Apr 2011 02:32:35 +0100

Garlic (Allium sativum L.) has been used as a food, a condiment, and for medicinal purposes for over many centuries. The typical physical characteristics of garlic cloves make the peeling to be very tedious and time-consuming operation. Considering the increasing demand for garlic products in domestic and export market, a low cost garlic clove peeler was developed and its performance was evaluated. The developed garlic clove peeler consisted of a 130 mm diameter, 400 mm long peeling chamber mounted on a mild steel (MS) angle frame. The top portion of the pressure chamber was connected with a 40 mm diameter reducer to separate the thin husk from the peeled material. A 10 mm galvanized iron (GI) pipe was inserted and positioned at a height of 60 mm from the top surface of the garlic bed to f...

The Use of an Inductive Coil System for the Description of Damages in Apple Tissue with Electrical Parameters

International Journal of Food Engineering — Thu, 21 Apr 2011 04:46:51 +0100

The main objective of this work was to determine if it is possible to distinguish between intact and destroyed apple tissue with an inductively working coil system. With conductive measurement, it is possible to measure the amount of destroyed cell in plant tissues. Destroyed cells in plant tissue can mean bad quality for the particular product. The advantage of the inductive measuring technique is the possibility to measure the complete product contactless and non-destructively during the production process. Hence, an inline measurement system could be developed. In order to destroy cells in apples, a freeze-thaw cycle was subjected to three different apples varieties (Braeburn, Jonagold and Idared). The changes of the electrical parameters were observed before and after the thermal treat...

Response Surface Optimization of Enzymatic Hydrolysis of Silver Sillago (Sillago sihama) with Low Bitter Taste

International Journal of Food Engineering — Thu, 21 Apr 2011 04:46:46 +0100

Eleven different commercial enzymes were used in this study, the MEAP (mixed enzymes for animal proteolysis) exhibited high nitrogen recovery, high degree of hydrolysis, and low bitter taste. In addition, at any DH, MEAP hydrolysates showed weakly bitter value. Response surface methodology (RSM) was used to optimize the hydrolysis conditions and the model equations were proposed. NR= + 93.73 - 4.29X1 + 3.68X2 +1.61X3 + 0.21X1X2 + 0.85X1X3 - 0.60X2X3 - 6.06 X12 - 1.6X22 + 0.054X32; DH= + 18.53 - 2.56X1 + 2.36X2 + 1.29X3 + 0.43X1X2 - 1.87X1X3 + 0.84X2X3 - 3.22 X12 - 0.44X22 - 0.52X32, where X1, X2 and X3 are the coded variables for temperature, E/S and pH, respectively. NR and DH at optimum conditions (temperature 55°C, E/S 1.5 percent, pH 7.5) were 95.76 percent and 20.19 percent, respecti...

Development of a Functional Beverage Formulation with High Protein Content, Inulin and Stevia

International Journal of Food Engineering — Sun, 17 Apr 2011 03:20:04 +0100

A beverage formulation with proteins of high quality, inulin, Stevia and C vitamin has been prepared. The protein source was bovine plasma which was concentrated and demineralized by a combined membrane methodologies as microfiltration, ultrafiltration and discontinues diafiltration. The use of inulin as protective agent to prevent protein concentrate denaturation during freeze-drying was assayed. The inulin is a versatile food ingredient and it also has health benefits. The powder obtained has improved sensory characteristic and high solubility. Stevia has been added as sweetness, being a low-carbohydrate, low-sugar food alternative. The formulation could be destined as protein supplement with functional properties or for special dietary use. (Source: International Journal of Food Enginee...

Feather Keratin Hydrolysis by an Aquatic Bacterium Meiothermus I40 from Hot Spring Water

International Journal of Food Engineering — Sat, 26 Mar 2011 03:54:00 +0100

In this study, the fermentation conditions of feather-degrading Meiothermus sp. strain I40 (I40) were optimized to enhance the biodegradation of chicken feather to hydrolysates. Initially, the factors essential for I40 keratinase production in submerged fermentation were screened, whereas response surface methodology (RSM) was then employed to evaluate the interactions among the effective factors. At first stage, eight fermentation parameters were screened using a Plackett-Burman (PB) design. Four effective factors identified by PB screening, namely feather concentration, tryptone concentration, yeast extract concentration, and incubation temperature, were further investigated their effects on keratinase production by RSM using central composite design (CCD). The I40 fermentation condition...

A New Model for Predicting Sorption Isotherm of Water in Foods

International Journal of Food Engineering — Sat, 26 Mar 2011 03:53:56 +0100

A new model for predicting sorption isotherms of type II and III based on the Polanyi theory is proposed. This model allows the prediction of the sorption isotherms at different temperatures from one experimental isotherm. The theoretical predictions of isotherms and isosteric heat were validated successfully using data from literature for twenty one foods. This method allows total experimental time and operation costs to be reduced. (Source: International Journal of Food Engineering)

Study of Whey Protein Concentrate Fortification in Cookies Variety Biscuits

International Journal of Food Engineering — Sat, 12 Mar 2011 00:06:48 +0100

The objective of present study was to explore the possibility of fortifying the whey protein concentrate in the formulation of biscuits. Biscuits were prepared from the blend (wheat flour and whey protein concentrate) containing various wt% levels of whey protein concentrate (0, 20, 25, 30, 35 and 40 percent) using traditional creaming method. Prepared biscuits were then evaluated for chemical, physical and sensory properties. It was observed that the thickness of whey protein concentrate fortified biscuits increased with increasing wt% level of whey protein concentrate, whereas diameter, spread ratio, spread factor and weight decreased with increasing wt% level of incorporation. The sensory evaluation supported incorporation of maximum 25 percent level of whey protein concentrate. (Source...

Optimization of Drying Kinetics and Quality Parameters of Broccoli Florets

International Journal of Food Engineering — Sat, 12 Mar 2011 00:06:32 +0100

Drying kinetics of broccoli florets in a tunnel dryer was studied. Effective moisture diffusivity (Deff) and activation energy for moisture diffusion (E0) were estimated. The effect of air temperature, air flow rate and particle size on antioxidant capacity, greenness and texture were calculated through a 23 factorial design. Air flow rate and temperature significantly affected drying time. Deff fluctuated between 2.82 x 10-10 and 2.00 x 10-9 (m2/s), and E0 was around 42 KJ/mol, agreeing with values reported in literature. The maximum antioxidant activity was obtained at 60°C, air flow rate of 4 m/s and 1.5 cm particle diameter, resulting in a 70 percent reduction in free radical scavenging ability and a 29 percent increase in total reductive capability. Air temperature had significant ef...

Modeling and Optimization of Mass Transfer during Osmosis Dehydration of Carrot Slices by Neural Networks and Genetic Algorithms

International Journal of Food Engineering — Sat, 05 Mar 2011 10:15:33 +0100

Osmotic dehydration, as a minimal processing method, has found increasingly wide prospects during the past few decades. This process involves mass transfer which is commonly modeled by applications of different procedures, mostly based on Fick's law. In this research, we approach the modeling process by first obtaining experimental measurement of carrot’s solid gain and water loss under different conditions of solution concentrations ( 20, 40 and 60% w/w), temperatures ( 40, 60 and 80°C) as well as time intervals (1-6h). Then two paradigms of artificial neural networks (ANN), feed forward neural networks (FFNN) and radial basis function neural networks (RBFNN) are applied and compared for modeling this process. Additionally, genetic algorithm is used to determine optimal conditions for ...

Electrode Configuration and Polarity Effects on Water Evaporation Enhancement by Electric Field

International Journal of Food Engineering — Fri, 04 Mar 2011 09:00:47 +0100

Applying an electric field to some water solutions or food materials has been shown experimentally to increase the drying rate. In this work, an electric field was applied cross the interface of water via electrodes located upright above the water and under the water container. The polarity and the strength of the electric field and the shape of the electrodes were altered to investigate their effect on the water evaporation rate. The results show that the water evaporation rate in AC field is higher than that in DC field, indicate that the AC field have more effect in water evaporation and heat transfer than DC field. With respect to the effect of electrode configuration, the evaporation rate in the point-to-plane electrode configuration is higher than that in parallel plate, wire-plane, ...

Investigation of EHD-Enhanced Water Evaporation and a Novel Empirical Model

International Journal of Food Engineering — Fri, 04 Mar 2011 09:00:42 +0100

This paper investigates the relationship between the enhanced evaporation rate by electric field, applied voltage (U) and electrode gap (d) in electrohydrodynamics-enhanced water evaporation. The electric fields produced by a single point-to-plane electrode configuration are used. In our experiments, the enhanced evaporation rate by electric field has shown increasing linearly with the U/d ratio. As regard the evaporation rate distribution on the plane electrode, the maximum evaporation rate is observed at the center of the plane (i.e., directly under the point electrode), and significantly decreased while the radial distance (i.e., radial distance from the point electrode centerline) increases. The evaporation rate is inversely proportional to the radial distance. A novel empirical model ...

Effect of the Microwave Irradiated Treatment on the Wine Sensory Properties

International Journal of Food Engineering — Thu, 03 Mar 2011 04:12:27 +0100

An instantaneous microwave irradiation method was applied to treat young dry red wine in order to accelerate the desired aging process during storing wine for the improvement of its taste quality. Effects of the microwave power and irradiation duration on the wine sensory property were investigated. Experimental results showed that microwave treatment had a significant effect on taste and total score, but no obvious effect was found on appearance, fragrance, fragrance duration and overall assessment. The influence of irradiation duration was significant on appearance, fragrance and total score, while not obvious on other indexes. The optimum conditions were obtained with microwave power 420 W and irradiation duration 5 min, and the result was corresponding to the content of chemical consti...

Optimization of Twin-Screw Extrusion Process to Produce Okara-Maize Snack Foods Using Response Surface Methodology

International Journal of Food Engineering — Tue, 01 Mar 2011 22:06:08 +0100

Okara-maize flour blends were extruded in a co-rotating twin-screw extruder in order to assess their suitability as snack foods. Response surface methodology (RSM) using a central composite design was used to evaluate the effects of process variables (extrusion temperature (120-180°C), screw speed (100-180 rpm) and feed composition (20-40 percent ww) and moisture content (14-22 percent ww)). Multiple regression equations were developed to describe the effects of each variable on product responses. The product characteristics such as bulk density, expansion index, appearance (colour, porosity), flavor (aroma, grittiness and off-odor), texture (hardness, crispness and brittleness) and overall acceptability were determined through experiments and sensory analyses. Through superimposed RSM co...

Co-Immobilization of Glucose Oxidase-Catalase: Optimization of Immobilization Parameters to Improve the Immobilization Yield

International Journal of Food Engineering — Sat, 19 Feb 2011 06:57:34 +0100

Co-immobilization of glucose oxidase (EC 1.1.3.4) and catalase (EC 1. 11.1.6) on non-porus glass surfaces using γ-aminopropyltriethoxysilane and polyethyleneimine as an activator and gluteraldehyde as cross linking agent has been carried out for its potential use. Polyethyleneimine was found to be a superior immobilization activator than γ-aminopropyltriethoxysilane. In present study, the effects of rough and smooth beads and optimization of the ratio of enzyme concentrations, activator material and concentration of the cross linking agent were investigated using response surface technology. With optimized concentration of glucose oxidase to catalase ratio (0.97), polyethyleneimine (150 mg/l) and gluteraldehyde (15 ml), the effect of glass bead concentration for maximum immobilization yi...

Air Drying Kinetics of Pomegranate Seeds

International Journal of Food Engineering — Thu, 17 Feb 2011 00:55:10 +0100

The thin layer drying of pretreated wild pomegranate seeds was conducted in a laboratory mechanical dryer at air temperatures of 55, 60 and 65Â°C. Six different mathematical models were used to predict the drying behavior. Thompson model was adjudged as the best model. The coefficients of this model were found to be correlated best with drying temperatures by using two degree polynomials. The effective diffusivity was determined to be 3.18 x 10-10 to 4.36 x 10-10 m2/s. The activation energy for diffusion was found to be 29.07 kJ /mol. The variation in shrinkage exhibited a linear relationship with moisture content. The rate constants for âaâ and âbâ parameters of colour were determined and their value was 0.0128 and 0.0136 min-1, respectively. (Source: International J...

Impact of Potato Chips Frying on the Quality Characteristics of Rapeseed Oil

International Journal of Food Engineering — Wed, 09 Feb 2011 00:27:23 +0100

The quality of rapeseed oil, as affected by potato chips frying at 180Â°C for 14 h, was investigated. The purpose of the study was to find out the quality deterioration of rapeseed oil with respect to time as affected by potato chips frying and to find the treatment that can be used for quality control. The parameters evaluated were refractive index, color, total polar material, free fatty acids, iodine value and peroxide value. There was a gradual increase in refractive index and color with time of frying which was found to be significant (P < 0.05) in the latter. Iodine value decreased significantly (P < 0.05) with time of frying. Peroxide value increased significantly (P < 0.05) with time of frying. After 14 h of frying, the total polar materials were 20.7 percent, indicating the need...

Evaluation of Conjugated Linoleic Acid Addition to a Chocolate Milk Drink

International Journal of Food Engineering — Fri, 04 Feb 2011 00:37:05 +0100

Aiming the development of a chocolate milk drink added of conjugated linoleic acid (CLA), some parameters, such as equipment type (blender and ultraturrax) and stirring time (1, 2 and 5 min) were tested. Chocolate milk drinks normally found in Brazilian market served as basis for obtaining the preparation in this study. The results showed that CLA incorporation to the dairy drink was more efficient using the blender (11,500 rpm, 3 min) than ultraturrax (11,000 rpm, 5 min), since it produced a higher emulsion stability, which was evaluated by visual inspection and optical microscopy (OM). The size of the oil droplets ranged from 2.28 mm to 11.80 mm and was evaluated only by MO due to the impossibility of using dynamic light scattering associated to the polydispersion of all samples which wa...

Functional Properties of Microbial Transglutaminase Modified Soybean Glycinin and β-Conglycinin

International Journal of Food Engineering — Thu, 03 Feb 2011 01:27:40 +0100

Soybean β-conglycinin and glycinin were polymerized by a microbial transglutaminase (MTGase), and some functional properties of these polymers, including solubility, heat stability and emulsifying, foaming, and gelling properties, were investigated. SDS-PAGE showed that the acidic subunits of glycinin and α, α’ subunits of β-conglycinin were easily susceptible to MTGase than basic subunits and β-subunits, respectively. Although MTGase treatment led to the decreases in solubility and emulsifying activity of β-conglycinin and glycinin, the significant improvements in their gelling and heat stability were observed (p < 0.05). In addition, the MTGase polymerization also increased the foaming property and emulsifying stability of glycinin. These results show that MTGase treatment could ...

Heat Inactivation of Mycobacterium avium subsp. paratuberculosis in Aseptically Prepared Ground Beef

International Journal of Food Engineering — Wed, 02 Feb 2011 03:18:33 +0100

In this study, aseptically prepared ground beef was obtained from beef semimembranosus muscle and inoculated with two stains of Map (ATCC 7080 and gN27) to determine the decimal reduction time (D-value) and temperature sensitivity (z-value) for each strain. A 25 g sample of meat was inoculated with 100 ul of culture to a final concentration of 107 cfu/g. The inoculum was evenly distributed in the meat, which was spread in a thin (2 mm) layer of to maximise heat transfer. Treatments were performed at 55, 60, 65 and 70 Â°C for times allowing a minimum 5-log reduction. D-values decreased significantly with temperature (P < 0.05) ranging from 80.5 Â± 6.1 minutes to 12 Â± 1 seconds for both Map strains. When compared to Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 7080, D-va...

Heat Transfer Enhancement of a Three Phase Circulating Fluidized Bed Fruit Juice Evaporator Using Inert Particles

International Journal of Food Engineering — Wed, 02 Feb 2011 03:18:27 +0100

In this paper, pumpkin juice concentration was carried out using a three-phase circulating fluidized bed evaporator. The flow and heat transfer characteristics of the evaporation process were investigated and parametric studies were conducted to identify the governing parameters in the process. It was found that the heat transfer efficiency was improved by 35 percent through addition of the inert particles into the two-phase evaporation process. Inert particles also inhibited the forming of fouling during the pumpkin juice concentration. A correlation equation of the boiling heat transfer coefficient was established for the three-phase circulating fluidized bed evaporator. This work improves the understanding of the three-phase circulating fluidized bed evaporator, which is beneficial to i...

Modelling with Response Surface Methodology of the Effects of Egg Yolk, Egg White, and Sodium Carbonate on Some of the Physical-Chemical and Sensory Properties of Beef Patties

International Journal of Food Engineering — Sat, 29 Jan 2011 03:40:21 +0100

This study was accomplished to determine the effects of sodium carbonate, egg yolk, and egg white powders on some of the physical-chemical and sensory properties of meat patties by using central composite design of response surface methodology. Meat patties were prepared using beef, lamb tail fat, and spices. Effects of the addition of egg yolk powder (0-1%), egg white powder (0-1%), and sodium carbonate (0-1%) on pH, proximate composition, cooking yield, and sensory properties were studied. The influence of egg yolk in the beef patties was found to be limited. However, the effects of egg white and sodium carbonate were found to be significant on several parameters. The levels of sodium carbonate up to 0.8% and egg white greater than 0.5% improved the physical-chemical and sensory properti...

Proximate Composition of Dry Fermented Turkish Sausage (Sucuk) as Affected by Ripening Period, Nitrite Level and Heat Treatment

International Journal of Food Engineering — Tue, 18 Jan 2011 04:21:45 +0100

In order to determine the potential for the reduction of nitrite level and ripening period with heat treatment, the effects of the ripening period (1-13 days), nitrite level (45-195 ppm) and heat treatment (30-90Â°C) on yield, moisture, fat and protein contents of sucuk were investigated using response surface methodology (RSM). Ripening period was found to be the main factor affecting the studied parameters of sucuk (p < 0.01). Moisture and yield decreased with increasing ripening period; however, fat and protein values increased with increasing ripening period. Higher levels of heat treatment, particularly above 60Â°C, increased protein values and decreased yield values. The changes in the studied parameters caused by additional nitrite levels were not found to be significant (p > 0....

Effective Parameters Consideration in Ohmic Heating Process in Two Phase Static System of Bio-Particle-Liquid

International Journal of Food Engineering — Tue, 18 Jan 2011 04:21:41 +0100

In this research, the effective parameters on Ohmic heating in aseptic and heating applications were studied. For this purpose, two- and three-dimensional Ohmic heating models in a two phase bio-solid-liquid system were developed. In these models, effects of particles distribution, particles size, effect of electrical conductivity on heating, overall heating of mixture and effect of salt concentration on heating rate were investigated. Temperature distribution profile, effects of intensity and distribution of electrical field on total temperature, and type of salt on phase electrical conductivity was also investigated. The modeling equation was solved with Finite Elements Method. The results showed that in Ohmic heating, heat diffusion in entire products was faster than the conventional me...

Modelling of Freezing Kinetics of Extract of Betel Leaves (Piper betle L.)

International Journal of Food Engineering — Thu, 13 Jan 2011 15:48:50 +0100

Betel is a native medicinal plant from central and eastern parts of Peninsular Malaysia. It is now an important commercial crop in India and Sri Lanka. There are various beneficial bioactivities discovered in this herb including anti-carcinogenic, anti-inflammatory, antioxidant, and antimicrobial properties. Freeze drying is one of the common methods used to dehydrate the herbal aqueous extract. This work studied the freezing process of aqueous extract of betel leaves (Piper betle L.). The effects of different freezing temperatures on the freezing kinetics were investigated. Freezing temperatures of -20, -25, -30Â°C were selected for the study. The freezing time which was taken as the time required for the temperature of the sample to reach the freezing temperature was determined from th...

High Hydrostatic Pressure Effect on Natural Microflora, Saccharomyces cerevisiae, Escherichia coli, and Listeria Innocua in Navel Orange Juice

International Journal of Food Engineering — Thu, 13 Jan 2011 01:32:37 +0100

An isostatic pressure system was used to treat fresh-squeezed orange juice inoculated with Saccharomyces cerevisiae, Escherichia coli, and Listeria innocua for selected times (come-up time, CUT, to 15 min plus CUT) and pressures (103 - 414 MPa). Specific agars, for each type of microorganism, were used for pour plating to count survivors after pressure treatment. Decimal reduction time values (Dp) were calculated from the first order kinetics modeling for S. cerevisiae (103-241 MPa), E. coli (103-241 MPa), and L. innocua (103-345 MPa) survivors in juice. Dp values of 6.1â52.1, 0.6â14.9, and 4.8â357.1 min were obtained for S. cerevisiae, E. coli, and L. innocua, respectively. zp values of 147.1, 92.6, and 59.2 MPa were calculated for these microorganisms, respectively. The co...

Formulation, Drying and Nutritional Evaluation of Ready-to-Eat Sapota (Achras zapota) Extrudes

International Journal of Food Engineering — Wed, 12 Jan 2011 17:57:38 +0100

One of the most interesting and desirable of all tropical fruits is sapodilla, a member of the family Sapotaceae. In the present study, a new and economical method has been developed for value addition to this fruit into a neutraceutical ready-to-eat formulation using drying as the main step. The drying of sapota fruit was carried out in two steps. In the first step, blanched sapota pulp was partially dried (up to moisture content 32 percent w/w on wet basis) in a convective dryer. The effect of different additives on the drying kinetics was studied and then proper drying conditions were selected. In the second step, different nutritional additives of interest were mixed with this partially dried pulp; subsequently, this mixture was extruded to a variety of shapes, which were finally dried...

A Survey on Packaging Materials and Technologies for Commercial Food Products

International Journal of Food Engineering — Wed, 12 Jan 2011 05:45:56 +0100

This paper presents the outcomes of a comprehensive and detailed analysis of the Italian food market, targeting the Fast Moving Consumer Goods products and aimed at defining the existing relationships between product characteristics and packaging technologies. A sample of 175 products has been examined, and the corresponding characteristics and packaging technologies were derived from an in-field investigation performed in large and small Italian retailers. Subsequent statistical analyses were first focused on providing descriptive statistics concerning the packaging materials used for food products. Then, cluster analysis was exploited to group products on the basis of the material used for the primary packaging. Discriminant analysis was also adopted to identify product characteristics t...

Hydrodistillation of Essential Oil from Cymbopogon flexuosus

International Journal of Food Engineering — Wed, 12 Jan 2011 05:45:53 +0100

Hydrodistillation is a potentially useful method to extract essential oil from various plant materials and was used to separate essential oil from Cymbopogon flexuosus (lemongrass). The yield is dependent on various parameters like weight of raw material, volume of water, size of raw material and nature of raw material. The purpose of this study was to find the optimum values of these parameters. The optimized conditions for the extraction were 50 g of raw material, 500 ml of water volume, plant size of 25 mm, and the yield obtained was 1.04 percent. The loss of about nine percent essential oil was observed during drying of leaves of lemongrass. Composition of the essential oil was analyzed by GC-MS and higher amount of oxygenated compounds, mainly citral, was found in each sample. There w...

Determination of the Convective Heat Transfer Coefficient (h) in the Sterilization of Retortable Pouches

International Journal of Food Engineering — Tue, 11 Jan 2011 14:54:22 +0100

The present work has employed an optimization process among experimental temperatures and those obtained by finite elements analysis (FEA) for the determination of the convective heat transfer coefficient (h) during a stand up retortable pouch process in a steam-air retort. The process was divided in four periods, and the values obtained were: 828.7 W.m-2.K-1 (hh1, first portion of heating; come up time); 538.5 W.m-2.K-1 (hh2, second portion of heating; ball time); 1293.6 W.m-2.K-1 (hc1, first phase of cooling); and 183.6 W.m-2.K-1 (hc2, second phase of cooling). The results obtained were validated experimentally by meat product sterilization, presenting good correlation between experimental values and those obtained by the model. The values obtained contribute to the studies of heat trans...

Suitability of Feature Extraction Methods in Recognition and Classification of Grains, Fruits and Flowers

International Journal of Food Engineering — Tue, 11 Jan 2011 14:54:19 +0100

This paper presents the suitability of feature extraction methods for the identification and classification of certain agriculture and horticulture crops. Primarily, agriculture/horticulture crops are recognized based on their shape, size, color, texture and the like. When crops exhibit different shapes and sizes, it is customary to choose the shape and size as the basic features. Certain crops are easily identified simply by color; for example, with crops like jowar, ground nut, pomegranate and mango, color becomes the discriminating feature. We have considered color as one of the features in this study. Some agriculture/horticulture crops have overlapping colors, such as wheat and ground nut or mango and orange. When we consider the bulk samples of such grains or fruits, the surface patt...

Isolation of Immunoglobulin from Chicken Egg Yolk using Single-Stage Ultrafiltration with 100-kDa Regenerated Cellulose Membranes

International Journal of Food Engineering — Tue, 11 Jan 2011 14:54:13 +0100

The aim of this work is to develop a membrane-based cost-effective process for the rapid isolation of immunoglobulin from chicken egg yolk. It was found that a single-stage ultrafiltration using a 100 kDa molecular weight cut-off regenerated cellulose membrane could be employed to isolate immunoglobulin from the crude feedstock. The effects of operational parameters (solution pH, ionic strength, stirring speed and permeate flux) on the transmission of immunoglobulin and the presence of impurity protein with molecular weight close to immunoglobulin were quantified using the parameter scanning ultrafiltration technique. Under optimized conditions, the purity of immunoglobulin obtained was about 85 percent after the single-stage ultrafiltration process, and the recovery of immunoglobulin from...

Relative Antioxidant Activity of Common Indian Herbs

International Journal of Food Engineering — Sat, 08 Jan 2011 02:18:37 +0100

Ten Indian herbs (Manjisth, Tagar, Kulfa, Khuskhus, Gokharu, Carrot, Kasni, Bathua, Soya ke Beej, Pudina), popularly used for medicinal purpose, were extracted in sonicator by methanol and water for the estimation of polyphenols and flavonoids. Antioxidant capacities (AOC) of extracts were evaluated based on their ability to scavenge the DPPH radical and FRAP Assay. The results showed that methanolic extract of all the plant materials had very high antioxidant activity. Amongst them, Pudina extract in the methanol showed highest value of AOC by both FRAP and DPPH methods (33 percent and 1.36 mg QEq / 100 g). Total phenol and flavonoids content were also evaluated for these extracts. It varied from 0.8736 to 6.3918 mg GAE / 100 g and 0.3642 to 1.9876 mg QE / 100 g. Total ash content and aci...

Optimization of Culture Conditions on Mycelial Grown in Submerged Culture of Cordyceps militaris

International Journal of Food Engineering — Sat, 08 Jan 2011 02:18:35 +0100

Statistical experimental design strategy (SES) was employed to optimize the culture conditions for the mycelial growth of C. militaris by submerged culture. Using Plackett-Burman design (PBD), liquid volumes in flask and fermentation time were identified as the significant variables that would highly influence mycelial growth, and these variables were subsequently optimized using response surface method (RSM). The steepest ascent method was used to access the optimal region of the culture condition. The results showed that the optimum values of the tested variables were 47.3 mL of liquid volumes in flask and 7.6 days of fermentation time. Under optimized culture conditions, the mycelial production was enhanced from 10.33 to 19.97 g/L. In comparison with that of original culture conditions,...

Effect of Raw Material and Processing Factors on the Production of Effervescent Artichoke (Cynara scolymus L.) Tea Tablets

International Journal of Food Engineering — Sat, 08 Jan 2011 02:18:33 +0100

An investigation was carried out to determine the effects of some factors on the production of effervescent artichoke tea tablets from dried artichoke (Cynara scolymus L.): extraction solvent composition, extraction temperature, extraction time, ratios of leaf, flower, stalk and root of dried artichoke, concentration of spray-drying solution, spray-drying temperature, spray-drying carrier, concentration of spray-drying carrier, proportion of effervescent agent, and components proportion of effervescent agent. The recommended extraction solvent was water with 10 percent of ethanol 96 percent (v/v), with an extraction temperature of 100Â°C, soak time of 14 hours, first extraction time of one hour, second extraction time of three hours. The dried artichoke raw material consisted of 1.0 part...

Evaluation of Moisture Diffusion Coefficient of Cylindrical Bodies Considering Shrinkage During Natural Convection Drying

International Journal of Food Engineering — Sat, 08 Jan 2011 02:18:30 +0100

An analytical diffusion model which considers the influence of the external resistance to mass transfer, sample finite geometry and shrinkage is proposed to simulate drying kinetic curves of cylindrical bodies. The convective mass transfer coefficients, hm at air-solid interface obtained from natural convection drying experiments on potato cylinders of length 0.05m and diameter 0.01m at different air drying temperatures were used for the model evaluation. Using Levenberg-Marquardt algorithm for optimization, an empirical relation describing effective diffusion coefficient of potato as a function of air temperature and material moisture content is proposed for finite and infinite cylinders with and without considering shrinkage. The significance of material moisture content in the proposed ...

Effects of Different Temperatures on Storage Quality of Heavily Salted Cod (Gadus morhua)

International Journal of Food Engineering — Thu, 06 Jan 2011 01:29:16 +0100

The aim of this study was to compare the effects of different storage temperatures (+2Â°C, -4Â°C, -12Â°C, -18Â°C and -24Â°C) and time (0, 1, 3 and 6 weeks) on the quality of heavily salted cod. The color, water content, water holding capacity (WHC), cooking yield, total volatile basic nitrogen (TVB-N) and trimethylamine (TMA) of the samples were determined. Results showed that the whiteness of the salted cod decreased slightly, whereas the yellow/orange color increased during the storage period. The WHC and cooking yield increased and were inversely related to water content. The TVB-N value increased slightly, whilst a lightly decrease in TMA value was observed. Storage at -4Â°C and lower temperatures had a detrimental influence on the color of the product which is the main qua...

Different Approaches for Mass Transfer Studies on Potato Cylinders and Slices during Solar Drying

International Journal of Food Engineering — Thu, 06 Jan 2011 01:29:14 +0100

In this paper, the influence of sample geometry and different solar drying conditions on mass transfer evaluation at food-air interface, hm obtained from different approaches is experimentally investigated. Two different approaches of hm estimation used in the analysis are based on the measurement of moisture loss rate data (direct method) and graphically computed values of drying parameters and moisture diffusion coefficient (indirect method). Drying experiments were performed with potato cylinders and slices of same thickness of 0.01 m with their respective length and diameter of 0.05 m using natural convection mixed-mode solar dryer and open air sun drying conditions. Results of analysis reveal that for each method of estimation, the cylinders vis-Ã -vis slices produce higher values o...

Improving Anti-Î±-Glucosidase Activity of Douchi Koji Using a Newly Isolated Strain of Bacillus subtilis B2

International Journal of Food Engineering — Thu, 06 Jan 2011 01:29:10 +0100

In attempt to develop an effective strategy to obtain douchi with anti-Î±-glucosidase functionality, Bacillus subtilis B2 was used as the initial microorganism to produce bacterial-type douchi koji capable of inhibiting Î±-glucosidase activity in the current study. Various fermentation conditions, such as soybean type, fermentation time and humidity, resulted in different anti-Î±-glucosidase activity of the douchi koji. Regardless of soybean or black bean, the douchi koji exhibited a drastic increase in anti-Î±-glucosidase activity during the first 48 h of fermentation and kept a slight increase from 48 h to 96 h. The anti-Î±-glucosidase activities of both soybean and black bean kojis displaying the lowest at the relative humidity of 70 percent, rose up to the highest at the humi...

Experimental Validation of Hybrid Photovoltaic-Thermal (PV/T) Greenhouse Dryer under Forced Mode

International Journal of Food Engineering — Tue, 04 Jan 2011 04:32:33 +0100

In this communication, a thermal model has been developed to predict the performance of hybrid photovoltaic-thermal (PV/T) greenhouse (roof type even span) dryer under forced mode. Based on energy balance, analytical expressions for temperatures of greenhouse air and produce (grape) surface as a function of design and climatic parameters have been developed. The analytical expressions for instantaneous and overall thermal efficiencies have also been developed. The experimental validations have also been carried out for greenhouse room air temperature, crop produce temperature and moisture evaporated etc. under composite climate of New Delhi (28Â°35'N, 77Â°12'E, 216 m above MSL). It has been observed that the developed thermal model was in well agreement with experimental data. It has b...

Computational Fluid Dynamics Analysis of Viscosity Influence on Thermal In-Package Liquid Food Process

International Journal of Food Engineering — Thu, 23 Dec 2010 02:27:52 +0100

Food processes must ensure safety and high-quality products for a growing demand consumer creating needs for its better unit operations knowledge. Computational fluid dynamics (CFD) have been widely used to better understand food thermal processes, one of the safest and most frequently used methods for food preservation. Fluid heating in enclosures is a complex phenomenon, which must be better understood. Although the relative convection importance at thermal liquid food process was recently evaluated trough CFD, viscosity influence as well as critical viscosity when a fluid behaves as a solid, has still not been evaluated. The present work has aimed to assess viscosity influence on thermal process lethality of in-package liquid food Typical thermal in-package process efficiency was compar...

Storage Stability of Kerman Pistachio Nuts (Pistacia vera L.)

International Journal of Food Engineering — Tue, 21 Dec 2010 02:59:15 +0100

Storage stability of whole split Kerman pistachio nuts (Pistacia vera L.) was examined on the samples stored at 5, 15, 25 and 35 Â°C and a relative humidity range of 11 to 87 percent. Rate constants of lipid oxidation reaction at 5 to 35 Â°C varied between 0.145 to 0.567 (month-1). The oxidation activation energy was 31.459 kJ/mol. Least product oxidation and lipolysis occurred at or near monolayer moisture content. (Source: International Journal of Food Engineering)

Effects of Drying Parameters on the Drying Kinetics of Fermented Ground Cassava Using a Rotary Dryer

International Journal of Food Engineering — Wed, 15 Dec 2010 00:05:03 +0100

The effects of drying parameters on the drying kinetics of fermented ground cassava were studied. Fermented ground cassava (TMS 30572) was dried in a bench scale rotary dryer at different inlet air temperature (115-230Â°C), inlet air velocity (0.83-1.55 m/s), feed drive speed (12-100 rpm), drum drive speed (8-18 rpm), relative humidity of inlet air (50 to 80 percent), and mass of feed (50-500 g). It is shown that inlet air temperature and inlet air velocity have the most significant effects on the drying rate of fermented ground cassava. A model which predicts the drying rate of fermented ground cassava as function of inlet air temperature and inlet air velocity is presented. Predictions of the model are compared with experimental data, and good agreement is obtained. For proper gelatini...

In Vitro Binding of Bile Salts by Different Insoluble Dietary Fiber Extracted from Brewersâ Spent Grain

International Journal of Food Engineering — Tue, 14 Dec 2010 04:07:22 +0100

Brewersâ spent grain (BSG), one of the major by-products of the brewing industry, has been mainly used as fertilizer or animal feed. Nevertheless, BSG was shown to contain a number of potentially high-value components such as insoluble dietary fiber (IDF). Recently, most studies on health benefits associated with IDF have been demonstrated. In the present study, the water holding capacity (WHC), swelling capacity (SC), oil holding capacity (OHC) and bile salts binding of the different insoluble dietary fiber extracted from BSG were tested in vitro. The results showed WHC, SC and OHC of the different IDF increased greatly. The WHC, SC and OHC of IDF extracted by alkaline hydrolysis were 2.63Â±0.11, 1.31Â±0.06 and 2.33Â±0.09 fold of BSG, respectively. The WHC, SC and OHC of IDF ex...

Response Surface Methodology for Studying the Effects of Feed Moisture and Ingredient Variations on the Chemical Composition and Appearance of Extruded Sorghum-Groundnut-Cowpea Blends

International Journal of Food Engineering — Tue, 14 Dec 2010 04:07:17 +0100

Studies were conducted to evaluate the effects of feed moisture and ingredient variations on the chemical composition and appearance of extruded sorghum-groundnut-cowpea blends using response surface methodology. Central composite rotatable design for k = 3 was used to study the combined effect of feed moisture (12 to 44 percent), groundnut concentration (zero to 10 percent) and cowpea level (zero to 20 percent) on the chemical composition and appearance of extruded ready-to-eat sorghum-legume blends in a single screw extruder. Product moisture, crude protein, crude fat, ash (minerals), crude fibre, carbohydrate and colour (L, a and b-values) were determined on the products using standard analytical methods. The results showed that irrespective of the feed moisture level, the extrusion pro...

Selection of Adsorbents and Determination of Parameters for the Separation of Glucose, Fructose, Sucrose and Fructooligosaccharides

International Journal of Food Engineering — Sat, 11 Dec 2010 07:18:54 +0100

This work aimed to describe the adsorption of sugars (glucose, fructose, sucrose and fructooligosaccharides) employing different adsorbents (celite, active carbon and NaX zeolite) by means of isothermal models. At the adsorbent selection step, the active carbon exhibited a higher affinity for the adsorption of fructooligosaccharides. On the other hand, the adsorbents NaX zeolite and celite presented the highest adsorption stability with glucose, giving values of 1.496 g glucose/g zeolite and 1.35 g glucose/g celite. Therefore, zeolite and celite were the adsorbents selected for the determination of isothermal kinetics and it was shown that the linear model (q*= k.C*) provided the best fit for the experimental data. The temperatures studied were 30, 40 and 50 Â°C, and the 50Â°C resulted...

Research and Application Progress of Insect Antimicrobial Peptides on Food Industry

International Journal of Food Engineering — Wed, 08 Dec 2010 23:31:58 +0100

This article overviews research and application progress of insect antimicrobial peptides on food industry, especially the existing problems for AMPs, which might be contributive in designing new and promising antimicrobial peptides for food preservatives. (Source: International Journal of Food Engineering)

Effect of Wine Properties and Operating Mode upon Mass Transfer in Micro-Oxygenation

International Journal of Food Engineering — Wed, 08 Dec 2010 02:52:14 +0100

All along wine-making and during its ageing, oxygen plays an important role for the evolution of the wine. Solubilization of oxygen into musts or wines occurs when gaseous oxygen is brought into contact with the liquid. In this work, the specific technique of wine micro-oxygenation is addressed through the evaluation of transfer capacity for oxygen solubilization. This was done considering the parameters likely to influence the saturation concentration of dissolved oxygen and the conventional volumetric mass transfer coefficient kLa, which quantifies the efficiency of the oxygen transfer. The study has shown that the sugar concentration in the must induces a viscosity enhancement which leads to a significant decrease of the kLa value. Surprisingly, it was also observed that a very low quan...

Mathematical Modelling of Thin Layer Sun and Solar Drying of Cassava Chips

International Journal of Food Engineering — Wed, 08 Dec 2010 02:52:11 +0100

In this paper, the effect of sun and solar drying and pretreatment conditions (soaking in water; soaking in water and then blanching; blanching and then soaking) on the drying characteristics and kinetics of cassava chips were investigated. The drying time was shorter for samples pretreated by soaking only (SK) compared to the others. It was observed that pretreatment conditions and drying method significantly (P < 0.05) affected the drying rate. The drying for all experiments occurred in the falling rate period with no constant rate period. Four mathematical models were studied for the description thin layer drying characteristics of pretreated cassava chips. The models considered were the Henderson and Pabis, Newton, Logarithmic and the Page model. Comparing the correlation coefficients ...

Evaluation of Two Mathematical Models Applied to Soybean Hydration

International Journal of Food Engineering — Tue, 07 Dec 2010 11:22:04 +0100

The predictions of the Hsu model of soybean hydration are compared with simulation results of the distributed parameter phenomenological model (DPP) that was developed in this study. The models were developed based on the same mass balance with one volume differential element of the Hsu model; however, the Hsu model admits an exponential variation of concentration while the DPP model admits equal diffusion and convection fluxes at the solid-fluid interface. The models are represented by a partial second order differential equation in relation to the radial position and a first order equation in relation to time, which were solved and numerically fitted using MATLAB routines and experimental data obtained from the hydration assays in the temperature range from 10 to 50 Â°C. The Hsu model ...

Colour Characteristics and Overall Acceptability of Fibre Enriched Biscuits: A Response Surface Approach

International Journal of Food Engineering — Tue, 07 Dec 2010 05:27:26 +0100

The effects of baking time and baking temperature on colour (L*a*b*), colour difference (ÎE) and overall acceptability (OAA) of biscuits made from different blends of refined wheat flour (RWF) and millet was investigated using a three factor central composite rotatable design (CCRD). ANOVA for response surface model demonstrated that the data could fit the three polynomial models adequately. All the models were found to be statistically sound to predict the responses. The colour values and OAA were significantly influenced by the processing variables at different levels of significance. The blend ratio, percent RWF, was found to have an overwhelming effect on all the colour values and OAA. It was predicted that the optimum product colour characteristics in terms of L*(29.45), a*(-105.01...

Relationships between Moisture Content and Physical Properties of Korean Honeys

International Journal of Food Engineering — Tue, 07 Dec 2010 05:27:20 +0100

Dynamic rheological and thermal characteristics of ten Korean acacia honeys with different moisture contents (18.4 to 20.4 percent) were evaluated as a function of moisture content using both a controlled stress rheometer for small-deformation oscillatory measurements and a differential scanning calorimeter (DSC). The honey samples displayed a liquid-like behavior at a subzero temperature (-5Â°C) with loss modulus (G") predominating over storage modulus (G'), showing a high dependence on frequency. Plots of dynamic moduli (G' and G") and complex viscosity (Æ*) versus moisture content gave better exponential relationships (R2 = 0.95-0.97) than the tan delta values (R2 = 0.89). Glass transition temperatures at onset (To) showed a better linear relationship (R2 = 0.87) with moisture cont...

Galacto-oligosaccharides Production Using Permeabilized Cells of Kluyveromyces marxianus

International Journal of Food Engineering — Tue, 30 Nov 2010 00:25:08 +0100

Galacto-oligosaccharides are non-digestible carbohydrates and are recognized as important prebiotics for than stimulation of the proliferation of lactic acid bacteria and bifidobacteria in the human intestine. GOS can be produced by a transgalactosylation reaction catalysed by Î²-galactosidase enzyme, and microorganisms can be used as a source of Î²-galactosidase. In this work, a process for producing GOS using permeabilized cells of Kluyveromyces marxianus CCT 7082 was proposed. The effects of the concentrations of lactose and enzyme, temperature and pH were studied using a fractional design followed by a central composite rotatable design. The optimum conditions for galacto-oligosaccharides production were found to be: lactose concentration 500 g/L, enzyme concentration 10 U/mL, 45Â...

Optimization of Ultrahigh Pressure Extraction of Momordicosides from Bitter Melon

International Journal of Food Engineering — Tue, 30 Nov 2010 00:25:04 +0100

Response surface methodology was used to optimize the conditions of ultrahigh pressure extraction of momordicosides from fresh fruits of bitter melon. The effect of extraction pressure, extraction time, ethanol concentration and solvent to sample ratio, and their interactions on yield of total momordicosides was investigated. Results showed that data could be well fitted to a second-order polynomial model. The independent parameters of extraction pressure, extraction time, solvent to sample ratio, all quadratics as well as the interactions between extraction pressure and solvent to sample ratio affected the yield significantly (p < 0.05). The model predicted that the optimal conditions were 423.1 MPa, extraction time 7.0 min, ethanol concentration 70.0 percent (V/V) and solvent to sample r...

Numerical Investigation on the Effect of Uncertainty in Thermal Diffusivity on Thermal Process Lethality of Canned Foods

International Journal of Food Engineering — Wed, 24 Nov 2010 04:32:31 +0100

The effect of uncertainty in thermal diffusivity on thermal process lethality was investigated for a model food of 8 percent canned bentonite suspension in two different can sizes. A developed computer program that account for can headspace thermal resistance and finite thermal resistance during cooling was used in this investigation. Six levels of errors in thermal diffusivity (Â±2%, Â±5% and Â±10%) were used to generate computer simulation time-temperature data at the geometric centre for both cans. The calculated lethality values from the time-temperature data when errors were imposed on thermal diffusivity were compared to that of the standard process. The results of the investigation revealed that error in thermal diffusivity of (-2%, -5% and -10%) resulted in under-processing, ...

Study on Postharvest Physico-Mechanical and Aerodynamic Properties of Mungbean [Vigna radiate (L.) Wilczek] Seeds

International Journal of Food Engineering — Sat, 20 Nov 2010 08:20:08 +0100

In this study, these properties of mungbean have been evaluated as a function of seed moisture content varying from 8.72 to 27.41% (d.b.). In this moisture range, the length, width, thickness, geometric mean diameter and surface area increased significantly (p < 0.05) from 4.32 to 5.10 mm, 3.33 to 3.54 mm, 3.30 to 3.59 mm, 3.62 to 4.01 mm and 41.1 to 50.6 mm2, respectively, whereas sphericity, porosity, bulk and true density decreased significantly (p < 0.05) from 83.80 to 78.63%, 39 to 36.56%, 841.3 to 730.7 kg/m3 and 1379.1 to 1151.8 kg/m3, respectively. Moreover, thousand seed mass, angle of repose and terminal velocity increased (p < 0.01) from 37.3 to 43.8 g, 31.6 to 40.3Â° and 4.9 to 5.8 m/s, respectively, by increasing the moisture content. The static coefficient of friction of mu...

Effect of High Hydrostatic Pressure Processing on Lycopene Isomers

International Journal of Food Engineering — Fri, 05 Nov 2010 04:42:57 +0100

Lycopene is known for its preventive mechanism of action against various types of cancers and chronic diseases. It is an acyclic C40 non-polar carotenoid that is found in tomatoes in various geometrical isomeric forms. In nature, the predominant form is the all-trans isomeric form (80-97%) in tomato and tomato related products. However research indicates that >50% of the lycopene in human body is found in the cis isomeric form, thereby leading to the hypothesis that the cis form is the more bioavailable /bioactive form in the human body.Todayâs consumers seek processed products that are minimally processed and have retained their overall quality. This has lead scientists to explore nonâthermal processing technologies like High Hydrostatic Pressure (HHP) processing technology. Our...

Simulation of the Transport Phenomena during Food Drying with Ohmic Heating in a Static System

International Journal of Food Engineering — Sat, 30 Oct 2010 11:01:10 +0100

In this article, the computational fluid dynamics (CFD) technique was used to simulate mass and heat transfer during the food drying via ohmic heating process. The effects of electrical field intensity, electrical conductivity, solid heating, liquid-solid conductivity and some parameters such as drying rate, moisture content and temperature changes on drying process of potato were investigated. The partial differential equations for the unsteady-state system were solved by the finite element method. In this modeling, simultaneous solution of the equations of heat transfer, moisture and electrical field was achieved. The results showed that ohmic heating process reduced drying time and accelerate the diffusion in the entire product in comparison with the other conventional methods. Therefor...

Development of a Linear Heat Source Probe and Determination of Banana Thermal Conductivity

International Journal of Food Engineering — Thu, 21 Oct 2010 03:22:48 +0100

In this study, such heat source probe was applied to measure the effective thermal conductivity of bananas and to evaluate its relation with the moisture contents of the product, in the range of 63-85% (wet basis). The values obtained to thermal conductivity ranged from 0.3 to 0.55 W/mÂ°C and were fitted to empirical equations. The predicted effective thermal conductivity presented satisfactory agreement with literature data and the best adjustment to thermal conductivity was given by the linear equation k = 0.8975U â 0.1568, with R2 of 0.8414. Furthermore, the banana was selected in this study because it is an important food due to its intense worldwide commercialization and high nutritional value and also because it has been increasingly produced in dry form, in a new range of pro...

Water Absorption Characteristics of Nigerian Acha (Digitaria exilis)

International Journal of Food Engineering — Wed, 20 Oct 2010 02:38:40 +0100

The water absorption characteristics of acha (Digitaria exilis) were investigated at temperatures of 40, 60, 80 and 100Â°C. The Peleg equation was used to model the hydration behaviour of the hydrated grains. The correlation coefficient for Pelegâs equation, which varied from 0.9931 to 0.9986, suggests that the equation gave a good fit to the experimental data. The water absorption capacity and hydration equilibrium water contents of the grain increased as the hydration temperature increased. The gelatinization temperature of acha was 600Â°C and the activation energy was 0.35 kJ mol-1 and 2.00 kJ mol-1 above and below this temperature. (Source: International Journal of Food Engineering)

Moisture Dependent Physical Properties of Grape Seeds

International Journal of Food Engineering — Tue, 12 Oct 2010 00:45:14 +0100

This study was carried out to determine the effect of moisture content on some physical properties of grape seed. Seven levels of moisture content varying from 12.26 to 24.61% (w.b.) were considered in this study. Length, width, thickness, geometric mean diameter, sphericity and 1000 seed mass increased by 2.58%, 3.63%, 8.36%, 4.78%, 2.14%, and 22.62%, respectively, with the increase of moisture content. Bulk and true density increased from 469.3 to 546.3 kg/m3 and 1058.7 to 1159.3 kg/m3, respectively, while porosity decreased from 55.67 to 52.87%. The angle of repose increased from 21.79 to 29.65Â° with the increase of moisture content. The hardness decreased from 58.72 to 23.34 N with increase in moisture content. The static coefficient of friction of seeds was determined on concrete, ...

Non-Thermal Microwave Reduction of Pathogenic Cellular Population

International Journal of Food Engineering — Tue, 12 Oct 2010 00:45:12 +0100

Pathogenic bacterial cells have been proved to be destroyed by heat at specific parameters such as dry heat, moist heat, thermal radiation, etc. In the study that was undertaken, it was found that microwaves had shown the ability to destroy bacterial cells at specific parameters without causing heating of the substrate, when using low dielectric substrates such as a glass slide (originally devised method). It was found that the bacterial cells, when exposed to microwaves as a smear on glass slide were reduced in cell population using 2.45GHz microwaves at various power levels (Watts). The degrees of reduction of bacterial cells in smears were estimated by growing the exposed smears in routine bacterial media and by studying the surviving bacterial growth density in a spectrophotometer at 6...

Aspect Ratio Analysis Using Image Processing for Rice Grain Quality

International Journal of Food Engineering — Sun, 03 Oct 2010 10:17:28 +0100

Determination of aspect ratio distribution is important for elongated, needle-shaped particles whose utility and/or value may depend on this feature. In this work rice grain is taken as an example of such a particle and its aspect ratio distribution in various samples is found using image processing. The samples examined were from three different grades (commonly termed as full, half and broken) sold in local market and priced according to their size. From the analysis, reference aspect ratios were assigned to classify the grains and hence determine the extent of off-size in each market grade. Further, the effectiveness of the technique to quantify mixed or adulterated grades was studied. It was found that it is possible to know the undesired content within 10 percent accuracy. (Source: In...

Kinetic and Thermodynamic Characteristics of Seaweed Dried in the Convective Air Drier

International Journal of Food Engineering — Fri, 24 Sep 2010 07:03:32 +0100

This study reveals the drying kinetics, specific heat and enthalpy of seaweed dried in the convective air drier. Comparison between convective hot air and sun drying process was also studied. At 50Â°C air temperature with 23.45 percent relative humidity and 1.55 ms-1air flow rate, it has been found that the moisture removal required 4 hours to reach moisture content of 19.66 percent wet basis with its drying rate at 0.28 x 10-3 kg water h-1. The data of drying rate showed that the drying process took place in the falling rate period. The specific heat and initial enthalpy were found to be 1.3842 kJkg-1Â°C-1 and 1672.69 kJkg-1, respectively. It was observed that the drying kinetics, specific heat, and enthalpy values vary significantly as functions of air temperature which seem to have ...

Cooling Optimization and Discrete Time Event Simulation

International Journal of Food Engineering — Fri, 24 Sep 2010 07:03:30 +0100

Like most universities, Texas A&M University-Kingsville has a public service mission to the constituents it serves. Here in South Texas, there is seafood, beef and vegetable processing. These can involve, to a lesser or greater extent, the freezing of products because major markets are not in the immediate region. We relate here a problem classical to chemical engineering, optimal heat transfer, which led to ramifications impacting other aspects of the overall enterprise. The heat transfer unit, a freezer, was optimized. However, it does not stand alone. It operates in a system in which upstream of the freezer there is variable input. The discrete time event simulation that evolved is a tool that chemical engineers should find useful, and the code SIGMA was especially helpful in constructi...

Physico-Chemical Characterisation of Opuntia dillenii Fruit

International Journal of Food Engineering — Fri, 24 Sep 2010 07:03:28 +0100

The chemical composition (moisture, Brix, protein, acidity, saccharose, fructose, glucose and minerals), the physical properties (Linear dimensions, mass, density, shrinkage and porosity) and equilibrium properties (sorption isotherms, enthalpy and entropy) of Opuntia dillenii fruit were determined. This fruit is characterized by an important value of water content, minerals and acidity. It has also a considerable porosity. Concerning the sorption isotherms, G.A.B. model is the best to examine the phenomenon of fixation and liberation of water molecules. (Source: International Journal of Food Engineering)

Desorption of Vitamin E from Silica-Packed Fixed-Bed Column by Isopropanol

International Journal of Food Engineering — Fri, 24 Sep 2010 07:03:26 +0100

Desorption of vitamin E from silica-packed fixed-bed column was studied as functions of column bed height, column temperature and flow rate of isopropanol. Isopropanol was the desorbing solvent and it was eluted through the columns saturated with vitamin E. The desorption profiles of all systems showed that vitamin E might desorb at two distinct rates simultaneously. The slow desorbing step was the rate-controlling process for recovery of vitamin E. The desorption rate increased with the decrease of column bed height and flow rate, but increased with increasing column temperature. This indicated that the desorption process was an endothermic process. The percentage recovery of vitamin E upon completion of desorption was considered high for all systems, ranging from 94.8 to 98.8%, with vita...

Combined Effect of High Hydrostatic Pressure and Nisin on Loss of Viability, Membrane Damage and Release of Intracellular Contents of Bacillus subtilis and Escherichia coli

International Journal of Food Engineering — Fri, 24 Sep 2010 07:03:23 +0100

Bacillus subtilis and Escherichia coli were chosen to investigate the combined effect of high hydrostatic pressure (HHP) and Nisin on loss of viability, membrane damage and release of intracellular contents of microorganisms. The results showed that the combination of 200 IU/mL Nisin and HHP exhibited a synergistic effect over 2 log on the inactivation of B. subtilis at pressure 300 MPa. The similar synergistic effect was observed on the membrane damage and release of intracellular contents of B. subtilis. The Nisin alone had no effect against E. coli, which belongs to gram negative bacteria. However, at pressure 300 MPa, Nisin caused the membrane damage from 55% to 80%. The synergistic effect of Nisin and HHP on loss of viability, membrane damage and release of intracellular contents of E...

Effect of Soy Cheese and Trisodium Citrate on Pizza Cheese

International Journal of Food Engineering — Fri, 24 Sep 2010 06:57:29 +0100

The effects of soy cheese (tofu) and trisodium citrate concentration on the organoleptic characteristics of pizza cheese were studied. Flavor, texture, stretchability, appearance, and overall acceptability of pizza cheese samples decreased significantly with increased proportion of soy cheese. Statistically, the color of cheese samples made from different blends of tofu and trisodium citrate was similar to that in the control sample. Stretchability, appearance, and overall acceptability of pizza cheese samples increased but not significantly (p>0.05) as concentration of trisodium citrate increased. However, the scores of flavor did not show significant difference. (Source: International Journal of Food Engineering)

Evaluation of Geometric Symmetry Condition in Numerical Simulations of Thermal Process of Packed Liquid Food by Computational Fluid Dynamics (CFD)

International Journal of Food Engineering — Tue, 21 Sep 2010 11:28:21 +0100

This study evaluated the condition of geometric symmetry used in numerical simulations of thermal process of packed liquid food via CFD. The analysis of temperature profiles obtained experimentally and through models built on 1/1, 1/4, 1/8, 1/16 and 1/32 of package geometry showed good correlation with the CFD simulations. The results indicate that the axial symmetry of the bottles allows the use of smaller models, which saves computational effort. (Source: International Journal of Food Engineering)

Relating Mechanical Changes at the Glass Transition with Water Absorption Behavior of Dry Legume Seeds

International Journal of Food Engineering — Fri, 27 Aug 2010 23:25:21 +0100

This work provides a novel view of explaining water uptake behavior commonly observed in legume seeds. A model proposed by Peleg to describe the mechanical changes in biomaterials transitioning from a glassy state to a rubbery state was used to describe water uptake by legume seeds exhibiting a lag during imbibition and to characterize the mechanical changes of the seed coat as affected by soaking time. The seeds characterized by Pelegâs model possessed seed coats with a glass transition temperature higher than ambient soaking conditions. Alternatively, the water uptake behavior of legume seeds that did not exhibit a lag phase was characterized by an exponential equation used in polymer science to model solvent sorption by materials above their glass transition. A modified exponential...

The Role of NaCl or KCl Act on Precipitation Rate and Some Properties of Mung Bean Starch

International Journal of Food Engineering — Fri, 27 Aug 2010 14:22:09 +0100

Mung bean starch has been manufactured by sour liquid processing for hundreds of years in China. Ions in sour liquid will impact the starch properties and vermicelli quality. To understand the role of the ions act on the processing and starch quality, different concentrations of NaCl or KCl effect on precipitation rate of starch slurry, starch properties and the potential quality of vermicelli were studied. Results showed that starch slurry took a shorter time to start precipitating when NaCl or KCl concentration increased from 0.027mol/L to 0.088 mol/L. Light transmittance, swelling power and peak viscosity of mung bean starch was significantly decreased from 0.02mol/L to 0.10mol/L NaCl or KCl. Increasing To, Tp, Tc and Tc-To was noticed from 0.02mol/L to 0.10 mol/L NaCl or 0.04mol/L to 0...

Gelatinization and Retrogradation of Hydroxypropylated Cornstarch

International Journal of Food Engineering — Thu, 26 Aug 2010 14:44:09 +0100

Gelatinization and retrogradation of a high amylose cornstarch modified by hydroxypropylation were studied by DSC. It was found that the gelatinization temperature of the starch was decreased and a narrow gelatinization range was measured by DSC after hydroxypropylation. The decreasing of the gelatinization temperature is explained by disrupting inter- and intra-molecular hydrogen bonds, while the narrowing of the gelatinization endotherm is explained by destroying the amylose-lipid complex. Morphologies of the starch granules with and without iodine treatment were studied under microscopy with normal and polarized lights. Brightness and birefringence decreased with increasing molar substitution since crystal structure in starch granular was partly destroyed. Weaker retrogradation was obse...

The Effects of Satay Marination on Three Beef Muscle Types

International Journal of Food Engineering — Thu, 26 Aug 2010 00:57:05 +0100

The effects of marination on the weight gain, cooking loss and Warner-Bratzler shear force of three beef muscle types, i.e. blade roast (BR), biceps femoris (BF) and semitendinosus (ST) were investigated by treating them in distilled water (as control), brine solution, tamarind juice, tamarind juice plus salt and satay marinade for 180 minutes. The weight gain of ST muscles were significantly higher (P < 0.01) than the BR muscles in brine solution, tamarind juice plus salt and satay marinade, while ST and BF muscles did not differ significantly (P > 0.01) in all the five treatments. For cooking loss, muscle types did not show a significant difference (P > 0.01) in all marinating treatments except for BR and ST muscles in tamarind juice (P = 0.00023). The presence of salt in tamarind juice ...

The Effect of Dilution Rate upon Protein Content and Cellular Amino Acid Profiles in Chemostat Cultures of Saccharomyces Cerevisiae CABI 039916

International Journal of Food Engineering — Thu, 19 Aug 2010 23:13:57 +0100

In the present study we examined the use of a chemostat system to investigate the impact of changes in the specific growth rate of Saccharomyces cerevisiae CABI 039916 on cellular amino acid profiles and total protein content. This experimental system allowed the unambiguous examination of the link between changes in dilution rate and the culture response, which would have been difficult in batch or fed-batch cultures. Alteration of the specific growth rate (via manipulation of the dilution rate) within a carbon and energy-limited chemostat has a significant impact on the physiology of Saccharomyces cerevisiae. Low dilution rates (0.2h-1) led to respirofermentative metabolism, where the cellular protein content was minimal (~40%). The content of nearly all amino acids in the yeast protein ...

Statistical Optimization and Neural Modeling of Amylase Production from Banana Peel Using Bacillus subtilis MTCC 441

International Journal of Food Engineering — Tue, 10 Aug 2010 01:55:18 +0100

Optimization of process parameters is of critical task in developing an industrial fermentation process for various reasons. Many techniques are available for experimental design and optimization of fermentation process parameters, i.e., fermentation medium composition and conditions, each having its own advantages and disadvantages. In this work response surface methodology (RSM) with central composite design (CCD) of experiments and artificial neural network (ANN) coupled with global optimization technique (TOMLABâs Direct AlogoritmâgblSolve) are used for optimization of process parameters for the production of alpha amylase using banana peel as the substrate and bacterial source Bacillus subtilis MTCC 441. A 46 run central composite design was used to plan the experiment with ...

Evaluation of Anthocyanin Content in Red and Blue Flowers

International Journal of Food Engineering — Tue, 10 Aug 2010 01:50:00 +0100

Anthocyanins are natural colorants which have gained a growing interest due to their extensive range of colors and beneficial health effects. The red and blue shades of 15 flowers were extracted with 1 % acidic methanol and these extracts were then screened for Total Anthocyanin content (TAC) using the pH method. In this paper the overall anthocyanin content of red and blue flowers was determined at room temperature (25Â°C). TAC accounts for the antioxidant activity of red and blue flowers. A quantitative relationship between acid-base and redox chemistry was also drawn. (Source: International Journal of Food Engineering)