International Journal of Dairy Technology via MedWorm.com

Traditional and innovative production methods of Fiore Sardo cheese: a comparison of microflora with a PCR-culture technique

International Journal of Dairy Technology — Thu, 18 Mar 2010 00:00:00 +0100

Fiore Sardo is a cheese manufactured on farms in Sardinia from raw ewe's milk, with Protected Designation of Origin (PDO). The aim of the study was to evaluate the effects of introducing a whey starter culture and specific mechanised cutting operations (innovative) vs traditional manufacture on the microbiological composition of the cheese, as assessed by conventional and molecular (PCR-Culture Tecnique) methods. Five batches were manufactured by innovative and traditional methods and there was no significant difference between the cheeses. (Source: International Journal of Dairy Technology)

The relationship of flow cytometry results with classical measures of bacterial counts in raw refrigerated milk

International Journal of Dairy Technology — Wed, 17 Mar 2010 00:00:00 +0100

Bulk milk was collected from 100 farms throughout the year and analysed after storage for either 24, 48 or 72 h, using flow cytometry. The total bacterial counts obtained by two methods [ndash] flow cytometry and standard plate count were compared and the conversion relationship between them was assessed: the results showed no effect of the age of the samples relationship between these two methods. (Source: International Journal of Dairy Technology)

Instant infusion pasteurisation of bovine milk. II. Effects on indigenous milk enzymes activity and whey protein denaturation

International Journal of Dairy Technology — Tue, 16 Mar 2010 00:00:00 +0100

Direct heat treatment of two milk types, skimmed and nonstandardised full-fat, was performed by instant steam infusion and compared with indirect heating. Infusion conditions were temperatures of 72[ndash]120°C combined with holding times of 100[ndash]700 ms, and indirect heat conditions were 72°C/15 s and 85°C/30 s. The activity of indigenous enzymes such as alkaline phosphatase, lactoperoxidase, xanthine oxidase and [gamma]-glutamyl transpeptidase was evaluated. Infusion temperature was the main determinant of inactivation. Whey protein denaturation represented by [beta]-lactoglobulin increased significantly with infusion temperature. The nonstandardised milk had a higher denaturation rate than skimmed milk. The effect of instant infusion on pH and milk fat globule size in relation to...

A comparison of two bench-scale anaerobic systems used for the treatment of dairy effluents

International Journal of Dairy Technology — Mon, 15 Mar 2010 00:00:00 +0100

The objective of this work was to compare two anaerobic reactor configurations, a hybrid upflow anaerobic sludge blanket (UASBh) reactor and an anaerobic sequencing batch reactor with immobilised biomass (ASBBR) treating dairy effluents. The reactors were fed with effluent from the milk pasteurisation process (effluent 1[mdash]E1) and later with effluent from the same process combined with the one from the cheese manufacturing (effluent 2[mdash]E2). The ASBBR reactor showed average organic matter removal efficiency of 95.2% for E1 and 93.5% for E2, while the hybrid UASB reactor showed removal efficiencies of 90.3% and 80.1% respectively. (Source: International Journal of Dairy Technology)

Comparison of Fascal cheese produced with natural, commercial or autochthonous cultures

International Journal of Dairy Technology — Thu, 11 Mar 2010 00:00:00 +0100

Lactic acid bacteria were isolated from raw ovine milk and Fascal cheese and used as two alternative inoculants for production of this Brazilian cheese. Microbiological counts and moisture of these cheeses were comparable to those observed in cheese made with a commercial starter. All cheeses showed absence of Salmonella spp., tolerable counts of coliforms, but coagulase-positive staphylococci counts exceeded the standard values. Cheeses produced with Lactobacillus plantarum LCN 28 and Lactobacillus rhamnosus LCN 43 showed better results than those observed for the other experimental combinations. Autochthonous cultures could be beneficial to the manufacture of high quality typical raw milk cheese. (Source: International Journal of Dairy Technology)

Influence of whey peptides on the surface activity of κ-casein and β-lactoglobulin A

International Journal of Dairy Technology — Wed, 10 Mar 2010 00:00:00 +0100

Whey protein hydrolysate (WPH) was fractionated by reverse-phase chromatography to obtain fractions of varying surface-hydrophobicities. A model oil[ndash]water interface (MI) was pre-coated with the WPH or fractions thereof. Contact angle ([theta]) of sessile drops of [kappa]-casein ([kappa]-CN) or [beta]-lactoglobulin A ([beta]-LGA) were measured on the MI. Pre-coating of MI with un-fractionated WPH decreased [theta], that is, increased surface activity, of both [kappa]-CN (35[ndash]8.3°) and [beta]-LGA (38[ndash]21.3°). Conversely, pre-coating of MI with the fractions significantly increased [theta] of both proteins as a function of hydrophobicity. Data provide insight into variability of whey protein functionality in food applications. (Source: International Journal of Dairy Technolo...

Nutritional and therapeutic value of fermented caprine milk

International Journal of Dairy Technology — Fri, 05 Mar 2010 00:00:00 +0100

Caprine milk is a nutritional and therapeutic food. The unique and beneficial characteristics of caprine milk that are superior to bovine milk include: better digestibility; greater buffering capacity; fat globules that are smaller in diameter and better distributed in the milk emulsion; higher content of short-chain fatty acids in the milk fat; higher content of zinc, iron and magnesium; stronger lactoperoxidase (antimicrobial) system as well as better immunological and antibacterial characteristics. The larger amounts of some minerals, such as calcium, zinc and magnesium, in caprine milk may influence the growth of lactic acid bacteria since they are a normal part of some enzymatic complexes involved in lactose fermentation. The higher whey protein content could also be significant becau...

The comparative analysis of a prophage remnant Lcazh1 in relation to other Lactobacillus prophages, particularly Lp3

International Journal of Dairy Technology — Thu, 04 Mar 2010 00:00:00 +0100

Lactobacillus casei Zhang has one defective prophage integrated into its chromosome, designated as Lcazh1. The 12.5-kb long nucleotide sequence contains 20 coding regions, 11 of which can be assigned functions by homologue searching and domain characterisation. With the exception of one uncharacterised protein cluster, genes encoded by Lcazh1 shared extensive similarities and strong synteny with the prophage Lp3 found in the chromosome of Lactobacillus plantarum WCSF1. It is the first time that prophages from different species of Lactobacillus were observed sharing clear similarities, implicating the possibility of lateral DNA transfer. (Source: International Journal of Dairy Technology)

Effect of heat treatment on the antibacterial activity of bovine lactoferrin against three foodborne pathogens

International Journal of Dairy Technology — Thu, 04 Mar 2010 00:00:00 +0100

The effect of different heat treatments on the antimicrobial activity of bovine lactoferrin against Escherichia coli O157:H7, Salmonella enteritidis and Listeria monocytogenes has been studied. We have observed that the heat treatments lower than 85°C for 10 min did not affect the antibacterial activity of the protein. Hydrolysates of bovine lactoferrin were found to be more active than the native protein against the three pathogens. Moreover, the antibacterial effect of bovine lactoferrin was also assayed in milk and whey, and although we found a reduction in the number of viable cells, this reduction was lower than in culture media. (Source: International Journal of Dairy Technology)

A comparison of the physico-chemical properties of low-cholesterol ghee with standard ghee from cow and buffalo creams

International Journal of Dairy Technology — Tue, 02 Mar 2010 00:00:00 +0100

Low-cholesterol ghee with 90% less cholesterol was prepared using [beta]-cyclodextrin. The physico-chemical properties such as Reichert-Meissl (RM) value, Polenske value, Butyro-refractometer (BR) reading at 40°C, Iodine value and free fatty acids (FFA) as oleic acid in cow standard ghee and the corresponding low-cholesterol ghee remained almost unaltered. A similar trend was also observed in buffalo ghee. Fat soluble vitamins ([beta]-carotene, A and E) in both cow and buffalo low-cholesterol ghee were very similar to that of respective standard ghee samples. However, 65 to 70% loss of vitamin D was observed in low-cholesterol ghee. (Source: International Journal of Dairy Technology)

Optimisation of sweetener blends for the preparation of lassi

International Journal of Dairy Technology — Fri, 26 Feb 2010 00:00:00 +0100

Sucrose was successfully replaced with sweetener blends for the preparation of lassi. Optimisation of the levels of sweeteners added individually or in blends, viz. binary, tertiary and quaternary and finally selection of the best blend among them was based on organoleptic assessment. Binary blend aspartame × acesulfame-k scored the highest when compared with the best optimised single sweetener aspartame, tertiary and quaternary blend in lassi and had nonsignificant differences with control in all sensory attributes. It showed maximum synergy in sweetness intensity in comparison to tertiary and quaternary blends. Use of binary blend resulted in 38% reduction of usage level when compared with single sweetener aspartame. (Source: International Journal of Dairy Technology)

The influence of breed on the organoleptic characteristics of Zamorano sheep's raw milk cheese and its assessment by instrumental analysis

International Journal of Dairy Technology — Thu, 25 Feb 2010 00:00:00 +0100

The aim of this study was to investigate the effects of three different somatic cell count (SCC) values on the sensory characteristics of sheep's milk cheeses from the Castellana and Churra breeds (allowed for Protected Designation of Origin Zamorano cheese manufacture) and the Assaf breed (foreign), determined by typical consumers and instrumentally. The results show that the sensory characteristics of hardness, intensity of taste, and pungency reflect a significant influence of the SCCs of the original milk whereas breed significantly affects colour intensity and hardness (Warner-Bratzler maximum shear force; WBSF). The instrumental parameters most closely related to the assessments of the typical consumers were WBSF and the value of a*, for hardness and colour respectively. (Source: Int...

Restrictions to the use of cleanrooms for packaging pasteurised milk

International Journal of Dairy Technology — Fri, 19 Feb 2010 00:00:00 +0100

The study evaluated the effect of packaging pasteurised milk inside an ISO Class 8 cleanroom and an external Class 7 antechamber. Chemical, microbiological and sensory analyses of three trials did not show evidence of improvements in the product shelf life, although the total airborne particle and the viable airborne counts were considerable higher outside the cleanroom than inside it. Post-pasteurisation contaminations inherent to the equipments should be considered in futures studies. Therefore, the use of cleanroom technology is an operational alternative to be taken into consideration, provided that the characteristics of the whole system is compatible with the high standards of the clean air. (Source: International Journal of Dairy Technology)

The effect of transglutaminase on the properties of milk gels and processed cheese

International Journal of Dairy Technology — Thu, 18 Feb 2010 00:00:00 +0100

The aim of this study was to investigate the influence of transglutaminase (TG) on rennet coagulation properties, and the impact on the properties of processed cheese. The TG was added before, at the same time as, and after the addition of rennet. The parameters moisture, total solids and proteins and physical parameters (syneresis index, wheying-off and rheological behaviour) were measured. The manufacturing of the milk gels treated with transglutaminase after rennet addition was shown to be an effective means of improving the physical properties (reduced synereseis index and increased consistency index) of processed cheese, possible by the occurrence of enzymatic cross-linking. (Source: International Journal of Dairy Technology)

The effect of wild lactic acid bacteria on the production of goat's milk soft cheese

International Journal of Dairy Technology — Tue, 09 Feb 2010 00:00:00 +0100

A blend of four wild strains of lactic acid bacteria, Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, Lactobacillus paracasei subsp. paracasei and Enterococcus faecalis, was used as starter to produce a goat's milk soft cheese. The cheese was analysed microbiologically, physicochemically and organoleptically through a 30-day period of ripening. Counts of the starter cultures increased in the first 24 h and then remained stable during ripening. Yeasts and coliforms were found at low numbers initially and gradually decreased to undetectable levels. Micrococcal counts were high throughout ripening. The end product was a soft cheese characterised by a mild, aromatic taste as well as a smooth structure. (Source: International Journal of Dairy Technology)

Assessment of aflatoxin M1 levels in selected dairy products in north-western Iran

International Journal of Dairy Technology — Thu, 31 Dec 2009 00:00:00 +0100

The purpose of this survey was to evaluate the natural occurrence and content of aflatoxin M1, AFM1, in dairy products marketed in Urmia. During September 2007, 40 samples of pasteurised milk, 40 samples of ultra high temperature-treated (UHT) milk, 40 samples of creamy cheese and 40 samples of Iranian Feta cheese were collected from different supermarkets in Urmia city. AFM1 contents were determined by the competitive enzyme-linked imunosorbent assay (ELISA) technique. All milk samples analysed showed a mean of AFM1 concentrations lower than the permissible level of 50 ng/kg in Iran (23.22 and 19.53 ng/kg in pasteurised milk and UHT milk respectively). The mean levels of AFM1 contamination were 43.31 ng/kg in Feta cheeses and 21.96 ng/kg in creamy cheeses. The potential risk of human expo...

Consumer-led Food Product Development

International Journal of Dairy Technology — Tue, 29 Dec 2009 00:00:00 +0100

(Source: International Journal of Dairy Technology)

Microparticulation of mixtures of whey protein and inulin

International Journal of Dairy Technology — Mon, 21 Dec 2009 00:00:00 +0100

In conclusion, it appears possible to successfully manufacture a low-calorie microparticulated whey protein based fat replacer using the dietary fibre inulin as the carbohydrate source. (Source: International Journal of Dairy Technology)

Effect of probiotic Lactobacillus casei Zhang on fermentation characteristics of set yogurt

International Journal of Dairy Technology — Mon, 21 Dec 2009 00:00:00 +0100

The effect of four inoculation levels of Lactobacillus casei Zhang (0.001, 0.01, 0.1 and 1.0 g/100 g) on the fermentation characteristics of set-style yogurt, and the changes in viable counts of lactic acid bacteria, pH value, syneresis, apparent viscosity, sugar and organic acid contents were determined during fermentation and storage over 21 days. The presence of 0.001 to 0.01 g/100 g L. casei Zhang did not affect the growth of the yogurt strains, and the yogurt inoculated with 0.00 1 g/100 g of L. casei Zhang had the highest apparent viscosity among the samples. However, a high inoculated level of L. casei Zhang (1.0 g/100 g) resulted in yogurts with inferior quality. (Source: International Journal of Dairy Technology)

Evaluation of different soybean varieties for manufacture of soy ice cream

International Journal of Dairy Technology — Mon, 21 Dec 2009 00:00:00 +0100

Soy ice cream is a delicious and nutritious frozen product. Seven varieties of soybean were evaluated for their suitability in the preparation of soy ice cream. Significant differences (p < 0.05) were found between the moisture, protein, fat and ash contents of ice cream mixes prepared from different soybean varieties. The viscosity of the ice cream mix increased, while specific gravity decreased, after ageing and freezing of the mix. Significant differences (P < 0.05) were observed in the over-run and melt down time of ice cream prepared from different soybean varieties. Soy ice cream prepared from variety PK-472 was rated organoleptically superior t0 other varieties. (Source: International Journal of Dairy Technology)

The development of burfi sweetened with aspartame

International Journal of Dairy Technology — Mon, 21 Dec 2009 00:00:00 +0100

Sucrose was successfully replaced with the sweetener aspartame for the preparation of the indigenous dairy product burfi. Analytical conditions were standardised for the solid phase extraction of aspartame and its degradation products from burfi followed by their reverse phase HPLC. Recovery using this method was 90[ndash]97%. Aspartame at a level of 0.065% of milk w/w scored highest in terms of sweetness perception and resembled control burfi in sweetness. Storage studies at 6[ndash]8°C revealed that aspartame-sweetened burfi resembled the control burfi in retaining the sensory profile, but showed an increase in acidity and microbial load and could not retain the texture. High-performance liquid chromatography analysis revealed no degradation of aspartame in burfi, establishing its stabi...

Effect of natural starter culture activity on ethanol content in fermented dairy products

International Journal of Dairy Technology — Fri, 11 Dec 2009 00:00:00 +0100

The influence of kefir grains' activation time on kefir pH changes and ethanol production was investigated. The proposed exponential pH model was used successfully to describe any decrease in pH during 24 h fermentation. Furthermore, the influence was investigated of differently active kefir grains on the correlation between ethanol and yeast population in grains and kefir drink respectively. Results showed that longer-activated grains produce more ethanol and have a larger number of yeasts than grains, which are activated for only a few days. The number of yeasts in a kefir product also increases over the grains' activation time. (Source: International Journal of Dairy Technology)

Indigenous enzymatic activities in ovine and caprine milks

International Journal of Dairy Technology — Fri, 11 Dec 2009 00:00:00 +0100

The objective of this review paper is the presentation of research findings about enzymes of ovine and caprine milks taking into consideration the bovine milk indigenous enzymatic activities as a reference. Information about indigenous enzymatic activities in these milk types focuses mainly on plasmin, lipoprotein lipase and on the enzymes that are used as thermal treatment indicators, i.e. alkaline phosphatase, and lactoperoxidase. Further research including the effects of genetic and environmental factors on the enzymatic activities is necessary. (Source: International Journal of Dairy Technology)

Production of proteinaceous antifungal substances from Lactobacillus brevis NCDC 02

International Journal of Dairy Technology — Fri, 11 Dec 2009 00:00:00 +0100

Forty standard Lactobacillus cultures were checked for their antifungal properties against nine standard fungi. Yeasts were found to be more resistant than moulds. Lactobacillus brevis NCDC 02 was selected for further studies due to the maximum antifungal activity and proteinaceous nature of antifungal substance production. The optimum production of antifungal substances was at 37°C for 48 h and at the initial pH of 6[ndash]7 of the medium. The antifungal substances were heat- and pH-stable. The antifungal substances were found to be hydrophobic and their molecular weight was found to be more than 1 kDa and less than 5 kDa. (Source: International Journal of Dairy Technology)

A comparison of the physicochemical, microbiological and aromatic composition of Traditional and Industrial Leben in Tunisia

International Journal of Dairy Technology — Tue, 08 Dec 2009 00:00:00 +0100

Traditional Tunisian Leben (TL) was produced according to the traditional method. Physicochemical and microbiological characteristics and major aromatic compounds were studied and compared to industrial Leben (IL) and experimental Leben (EL). The results show a decrease in lactose content and pH value and an increase in lactic acid during spontaneous fermentation. TL and EL were characterised by higher protein, lactose and ash contents but were less fatty and acidic than IL. Lactic acid bacteria (LAB) and yeasts present in TL were responsible for lactic acid fermentation and aroma development. The LAB and yeast counts in TL were higher than that in EL and IL. Dynamic headspace extraction procedure shows the existence of four major volatile compounds: acetaldehyde, ethanol, diacetyl and ace...

Identifcation of yeasts from raw milk and selection for some specific antioxidant properties

International Journal of Dairy Technology — Fri, 04 Dec 2009 00:00:00 +0100

Eleven different species of yeasts isolated from raw milk, such as Issatchenkia orientalis, Pichia fermentans, Rhodotorula mucilaginosa and Yarrowia lipolytica were identified using an integrated approach, including phenotypic and genotypic methods and the API 20C AUX system. Eleven selected strains which tolerated low pH levels, gastric juice and bile salt were further analysed for the presence of functional traits useful for probiotic application as antioxidants. The ability to scavenge DPPH (2, 2-diphenyl-1-picrylhydrazyl) and inhibit linoleic acid peroxidation indicated that P. fermentans BY5 and HJ15 may be promising candidate strains for use as probiotics with antioxidant activity. (Source: International Journal of Dairy Technology)

Functional milks and dairy beverages

International Journal of Dairy Technology — Thu, 03 Dec 2009 00:00:00 +0100

This article reviews recent scientific, technological and commercial developments in the functional dairy-based beverage sector. (Source: International Journal of Dairy Technology)

Characterisation of anti-Listeria monocytogenes bacteriocins from Enterococcus faecium strains isolated from dairy products

International Journal of Dairy Technology — Tue, 24 Nov 2009 00:00:00 +0100

Bacteriocin-producing lactic acid bacteria were isolated from 34 samples of dairy products. Nine bacteriocin producers were phenotypically and genotypically identified as Enterococcus faecium. By means of PCR-techniques, enterocin A was characterised in all of the nine bacteriocin-producing Enterococcus isolates. Enterocin-producing lactic acid bacteria were the most abundant in dairy products collected from different areas in Iran. Maximum bacteriocin production by Enterococcus faecium strains was detected in the stationary phase of growth. Bacteriocins produced by all isolates were found to have anti-listerial activity in sterile milk. The purified bacteriocins were identified as (Source: International Journal of Dairy Technology)

Proteolytic activity among psychrotrophic bacteria isolated from refrigerated raw milk

International Journal of Dairy Technology — Thu, 12 Nov 2009 00:00:00 +0100

Psychrotrophic bacteria were isolated from refrigerated raw milk from a processing plant in Southern Brazil. Psychrotrophic counts were between 4.9 and 7.8 log cfu/mL, and 5.3 to 7.2 log cfu/mL, for samples collected at the truck and the milk storage silo, respectively. Among the bacterial isolates, 90% were Gram-negative. Most strains presented low proteolytic activity, but strains of Burkholderia cepacia, Klebsiella oxytoca and Aeromonas sp. showed higher than 20 U/mL on azocasein as substrate. Crude proteases from selected strains were resistant to conventional heat treatments and caused coagulation of UHT milk after 5 days storage at room temperature. (Source: International Journal of Dairy Technology)

Screening of some potentially probiotic lactic acid bacteria for their ability to synthesis conjugated linoleic acid

International Journal of Dairy Technology — Wed, 11 Nov 2009 00:00:00 +0100

Strains of potentially probiotic lactobacilli, propionibacteria, leuconostoc, lactococcus, enterococcus, and pediococcus, were tested for their ability to convert linoleic acid to conjugated linoleic acid (CLA). Growth and CLA production were followed during incubation for 48 h in reconstituted skim milk containing 0.2% lipolysed sesame oil. Lactococcus lactis subsp. lactis biovar diacetylactis and Leuconostoc mesenteroides subsp. mesenteroides gave the highest CLA production. Also, the effect of lipolysed oil concentration on the growth and CLA production of six strains were studied in medium containing 0.0[ndash]1% lipolysed oil. Leuconostoc mesenteroides subsp. mesenteroides and Lac. lactis subsp. lactis biovar diacetylactis gave maximum dienes in medium containing 0.6% and 0.8% lipolys...

Entrapment of nutrients during cholesterol removal from cream by crosslinked β-cyclodextrin

International Journal of Dairy Technology — Tue, 10 Nov 2009 00:00:00 +0100

This study was designed to elucidate the quantities of nutrients entrapped during cholesterol removal from cream by crosslinked [beta]-cyclodextrin ([beta]-CD, 4[ndash]12%, w/v) and to evaluate the amounts of the residual [beta]-CD in cholesterol-removed cream treated by crosslinked [beta]-CD. The content of lactose in the control cream (without the treatment by crosslinked [beta]-CD) was 2.74%, and the amounts of lactose entrapped by crosslinked [beta]-CD ranged from 0.00 to 0.03%. The total amounts of the entrapped short-chain free fatty acid (FFA) and free amino acid (FAA) ranged from 0.04 to 0.12 ppm and from 0.37 to 0.48 [mu]mol/mL, respectively. The amounts of the entrapped water-soluble vitamins (L-ascorbic acid, niacin, thiamine and riboflavin) ranged from 0.01 to 0.05 ppm, from 0....

The influence of transglutaminase treatment on functional properties of set yoghurt

International Journal of Dairy Technology — Mon, 02 Nov 2009 00:00:00 +0100

The objective of this study was to investigate the effect of transglutaminase (Tgase) on the functional properties of set yoghurt, due to enzymatic cross-linking of the milk proteins. Yoghurt samples were prepared from three formulations: reconstituted skim milk, and whole milk containing two different solid-non-fat (SNF) content, with four enzyme treatments: Control (no enzyme) and three microbial Tgase treatments: Pre-incubated 90 min, Pre-incubated and inactivated after 90 min, Not pre-incubated. The modifications which were caused by Tgase were found to be more clear when Tgase was active in set type yoghurts. It was found that nonfat yoghurt sample with lower SNF content can be produced with improved textural properties using Tgase. (Source: International Journal of Dairy Technology)

Storage stability of traditional Tunisian butter oil produced from spontaneous fermentation of cow's milk

International Journal of Dairy Technology — Mon, 19 Oct 2009 23:00:00 +0100

Physicochemical characteristics of traditional Tunisian butter (TTB) and thermal stability of the butter oil were studied. Thermal stability of samples was estimated by using the accelerated shelf life testing method. Effect of heating on some quality characteristics of traditional Tunisian butter oil (TTBO) was investigated and compared at different temperatures (60°C, 100°C and 130°C). Induction period of sample heated at 60°C was important compared to that at 100°C and 130°C. This result may indicate the sensitivity of TTBO to elevated temperature. Absorption at 232 and 270 nm, acidity and PV increased rapidly after reaching the oxidation induction time. The temperature had a significant effect on the formation of oxidation products in traditional butter oil (TTBO). Fatty acid com...

Functional Dairy Products Volume 2 (2007)

International Journal of Dairy Technology — Thu, 15 Oct 2009 23:00:00 +0100

(Source: International Journal of Dairy Technology)

Handbook of Fermented Functional Foods, 2nd edition (2008)

International Journal of Dairy Technology — Thu, 15 Oct 2009 23:00:00 +0100

(Source: International Journal of Dairy Technology)

Dictionary of Food Science & Technology, 2nd edition

International Journal of Dairy Technology — Thu, 15 Oct 2009 23:00:00 +0100

(Source: International Journal of Dairy Technology)

Case Studies in Food Product Development (2008)

International Journal of Dairy Technology — Thu, 15 Oct 2009 23:00:00 +0100

(Source: International Journal of Dairy Technology)

The textural properties of soy paneer

International Journal of Dairy Technology — Thu, 15 Oct 2009 23:00:00 +0100

Toned dairy milk and soy milk were mixed in different proportions and coagulated at various temperatures to produce paneer blends, and their textural properties were evaluated. As the soy milk proportion in the blend increased from 0% to 50%, hardness, cohesiveness and chewiness of the samples decreased initially, but further increase in the blend from 50% to 100% cause these values to increase slightly. The proportion of soymilk in the prepared paneer had a significant effect on hardness, cohesiveness, adhesiveness, chewiness and yield, whereas the coagulation temperature affected cohesiveness and yield. The process parameters did not show any effect on the springiness. (Source: International Journal of Dairy Technology)

Probiotic buttermilk-like fermented milk product development in a semiindustrial scale: Physicochemical, microbiological and sensory acceptability

International Journal of Dairy Technology — Thu, 15 Oct 2009 23:00:00 +0100

Probiotic buttermilk-like fermented milk in different flavors in versions with sucrose and sucralose were processed in a pilot plant. The Mesophilic Aromatic Culture CHN-22 and Bifidobacterium animalis Bb12 were the cultures employed for fermentation. Physicochemical composition, apparent viscosity, diacetyl content, viability of cultures during storage, and acceptance of product via sensorial analysis were assessment factors. The high viability of the probiotic culture was observed (average 8.08 log cfu/ml) during refrigerated storage (28 days) of buttermilk and good acceptance of the product via sensory test. However, the probiotic culture might have been responsible for the loss of diacetyl, a volatile compound that is a characteristic feature of the product. (Source: International Jour...

Effect of some technological parameters on microbiological, chemical and sensory qualities of Civil cheese during ripening

International Journal of Dairy Technology — Thu, 15 Oct 2009 23:00:00 +0100

The objective of this research was to determine the effects of different ripening methods [brine salting, dry salting, incorporating with Lor cheese (LR) and vacuum packaging] of Civil cheeses on its microbiological, chemical and sensory properties. Civil cheeses were analysed on the 2nd, 30th, 60th and 90th day of ripening. Chemical compositions of the cheeses were significantly different. While the highest dry matter and titratable acidity values were determined on dry salted cheeses, the highest fat and fat in dry matter contents were found in Civil cheese ripened together with LR. The water-soluble nitrogen and ripening index values were lower in cheese ripened incorporating with LR. Excessive proteolysis was not seen in any of cheese samples. The ripening in different methods affected...

Oaxaca cheese: Manufacture process and physicochemical characteristics

International Journal of Dairy Technology — Thu, 15 Oct 2009 23:00:00 +0100

The objective of this study was to document the method of manufacture and its physicochemical characteristics. There are variations in the process of manufacturing and has been affected by external influences such as time and temperature. There were variations in the physicochemical characteristics as the processes were not standardised, the variations being in protein from 150.3 to 241.5 g/kg; in fat from 170 to 253.3 g/kg; in pH from 4.9 to 5.8; in salt from 8.4 to 36.2 g/kg; in moisture from 124.1 to 610.3 g/kg and in ashes from 18 to 41.8 g/kg. (Source: International Journal of Dairy Technology)

Effect of the addition of trisodium citrate and calcium chloride during salting on the rheological and textural properties of Cheddar-style cheese during ripening

International Journal of Dairy Technology — Thu, 15 Oct 2009 23:00:00 +0100

The effect of addition of trisodium citrate (TSC) and calcium chloride (CaCl2) on the textural and rheological properties of Cheddar-style cheese was investigated. Cheese curds were salted (2.5%) with NaCl (control) or NaCl supplemented with either TSC or CaCl2 with a constant ionic strength. Casein-bound calcium phosphate decreased upon addition of TSC and increased upon addition of CaCl2. Addition of CaCl2 resulted in increased hardness. Addition of TSC resulted in reduced hardness but more elastic cheeses at high temperatures. The addition of TSC or CaCl2 at salting had a significant effect on cheese rheology and texture. (Source: International Journal of Dairy Technology)

Estimation of sugars in milk by HPLC and its application in detection of adulteration of milk with soymilk

International Journal of Dairy Technology — Thu, 15 Oct 2009 23:00:00 +0100

A high-performance liquid chromatography method is described for the detection of adulteration of milk with soymilk, based on separation of sugars on NH2 column and their detection by refractive index detector. Sugars were extracted with 20% acetonitrile in the presence of Carrez solutions and quantified. Recovery of added raffinose to soymilk was 96.3%. Owing to relative high concentration of lactose in milk or adulterated milk, lactose peak was very broad and spread to retention time corresponding to sucrose and raffinose. However, stachyose peak remained well separated. Presence of stachyose peak in milk can be used for the detection of adulteration of milk with soymilk and the method can detect upto 5% soymilk in milk. (Source: International Journal of Dairy Technology)

Physicochemical characteristics and renneting properties of camels' milk: A comparison with goats', ewes' and cows' milks

International Journal of Dairy Technology — Thu, 15 Oct 2009 23:00:00 +0100

A great variability in physicochemical and microscopic characteristics of individual milk has been observed leading to the presence of differences in kinetics of the renneting reaction and in drainage ability. Furthermore, this study shows that casein concentration, total calcium content and mean diameter of casein micelles are the principal variables explaining the major part of the variation in the renneting properties. Finally, several relationships between coagulation characteristics, drainage ability and some compositional parameters of these kinds of milk were highlighted. (Source: International Journal of Dairy Technology)

Instant infusion pasteurisation of bovine milk. I. Effects on bacterial inactivation and physical–chemical properties

International Journal of Dairy Technology — Thu, 15 Oct 2009 23:00:00 +0100

Two types of milk, skim milk and non-standardised raw milk, were heat treated using direct heating by instant infusion pasteurisation with treatment temperatures in the range from 72°C to 120°C and with holding times of less than 1 second. Indirect heating by HTST pasteurisation (72°C for 15 seconds) was used for comparison. The inactivation of microorganisms reached at least the same level when using instant infusion pasteurisation compared to HTST pasteurisation. Changes in the physical-chemical properties were observed in the skim milk fractions of instant infusion pasteurised non-standardised milk, whereas for instant infusion pasteurised skim milk less influence from the treatments was observed. (Source: International Journal of Dairy Technology)

Probiotic fermented milks: Present and future

International Journal of Dairy Technology — Thu, 17 Sep 2009 23:00:00 +0100

Milk and dairy products have been part of human nutrition since ancient times, constituting an important part of a balanced diet. Fermented dairy products containing living micro-organisms have traditionally been used to restore gut health, being among the pioneers in functional foods. Such utilization of live micro-organisms forms the basis of the probiotic concept, which constitutes a fast growing market for the development of new products. In this article, we review the current status of fermented milk as a vehicle for delivery of beneficial bacteria and look into future new directions and challenges. (Source: International Journal of Dairy Technology)

Utilization of buttermilk for the preparation of carbonated fruit-flavoured beverages

International Journal of Dairy Technology — Mon, 14 Sep 2009 23:00:00 +0100

This study set out to utilize buttermilk to formulate beverages. Various filtration techniques, such as prefiltration and ultrafiltration were used, and orange, mango and pineapple juices were added with a view to making them more nutritious and acceptable organoleptically. Carbonation remarkably improved the sensory characteristics of the beverages, which were found to be more acceptable than the market samples. The beverage containing 12% sugar, 24% pineapple juice and processed by ultrafiltration was adjudged the best compared with other combinations. (Source: International Journal of Dairy Technology)

Utilisation of buttermilk for the preparation of carbonated fruit-flavoured beverages

International Journal of Dairy Technology — Sun, 13 Sep 2009 23:00:00 +0100

This study set out to utilise buttermilk to formulate beverages. Various filtration techniques, such as prefiltration and ultrafiltration were used, and orange, mango and pineapple juices were added with a view to making them more nutritious and acceptable organoleptically. Carbonation remarkably improved the sensory characteristics of the beverages, which were found to be more acceptable than the market samples. The beverage containing 12% sugar, 24% pineapple juice and processed by ultrafiltration was adjudged the best compared with other combinations. (Source: International Journal of Dairy Technology)

The effect of Lallemantia royleana (Balangu) seed, palmate-tuber salep and carboxymethylcellulose gums on the physicochemical and sensory properties of typical soft ice cream

International Journal of Dairy Technology — Wed, 09 Sep 2009 23:00:00 +0100

This study was aimed primarily at determining the suitability of two Iranian sources of hydrocolloid, Balangu seed and palmate-tuber salep (PTS), for the production of ice cream mix. For this purpose, the effect of these gums and carboxymethylcellulose (CMC) on some physicochemical and sensory characteristics of a typical soft ice cream was investigated. In comparison with carboxymethylcellulose, Balangu seed did not make a significant difference (P > 0.05) to most characteristics and could be used as a suitable stabilizer. Although products prepared using only the palmate-tuber salep showed more differences from the corresponding ones with carboxymethylcellulose, the variations were not significant. (Source: International Journal of Dairy Technology)

Effects of homogenization conditions on the physical properties of high-fat ice cream

International Journal of Dairy Technology — Mon, 31 Aug 2009 23:00:00 +0100

The effect of homogenization pressure on the physical properties of high-fat ice cream was investigated. Nonhomogenized ice cream was hard, with low resistance to meltdown, and ice crystals grew rapidly therein. Fat globule networks were not formed in the nonhomogenized ice cream. The ice cream homogenized at 5 MPa or more was harder and showed a higher resistance to meltdown. Ice crystals in the ice cream homogenized at 5 MPa or more grew slowly. The physical properties of each ice cream varied with homogenizations from 5 to 25 MPa and could be controlled by homogenization pressure. (Source: International Journal of Dairy Technology)

Effects of homogenisation conditions on the physical properties of high-fat ice cream

International Journal of Dairy Technology — Sun, 30 Aug 2009 23:00:00 +0100

The effect of homogenisation pressure on the physical properties of high-fat ice cream was investigated. Nonhomogenised ice cream was hard, with low resistance to meltdown, and ice crystals grew rapidly therein. Fat globule networks were not formed in the nonhomogenised ice cream. The ice cream homogenised at 5 MPa or more was harder and showed a higher resistance to meltdown. Ice crystals in the ice cream homogenised at 5 MPa or more grew slowly. The physical properties of each ice cream varied with homogenisations from 5 to 25 MPa and could be controlled by homogenisation pressure. (Source: International Journal of Dairy Technology)

Stability of β-lactoglobulin/micellar casein mixtures on heating in simulated milk ultrafiltrate at pH 6.0

International Journal of Dairy Technology — Fri, 21 Aug 2009 23:00:00 +0100

The stability of [beta]-lactoglobulin ([beta]-lg)/micellar casein (MC) mixtures was examined on heating at pH 6.0 in increasing levels of lactose-free simulated milk ultrafiltrate (SMUF). Heated [beta]-lg associated with MC to form stable particles (up to 771 nm in size in SMUF × 0.5). Higher levels of SMUF induced reductions in the charge on particles, resulting in greater aggregation and precipitation. Results indicated that the nonthiol-containing [alpha]s1- and [beta]-casein fractions showed greater interaction with [beta]-lg on heating than the thiol-containing fractions ([alpha]s2-casein and [kappa]-casein). Casein proteins and their fractions have potential application in the development of heat-stable dairy-based beverages. (Source: International Journal of Dairy Technology)

The potential of probiotic fermented milk products in reducing risk of antibiotic-associated diarrhoea and Clostridium difficile disease

International Journal of Dairy Technology — Wed, 12 Aug 2009 23:00:00 +0100

Currently, the burden of infective antibiotic-associated diarrhoea (AAD) and Clostridium difficile-associated disease (CDAD) is placing considerable strain on health services. The potential of probiotics has been investigated, particularly whether they may help reduce the vulnerability of the elderly to these diseases. Probiotic mechanisms of activity include helping to maintain the normal intestinal microbiota and supporting its ability to resist colonization by pathogens as well as immune modulation. Despite conflicting results from meta-analyses, there is now increasing evidence that certain Lactobacillus probiotic strains may reduce the risk of AAD and CDAD. Several recent studies report positive results with probiotic-fermented dairy products. (Source: International Journal of Dairy T...

Influence of starter culture type and incubation temperatures on rheology and microstructure of low fat set yogurt

International Journal of Dairy Technology — Mon, 03 Aug 2009 23:00:00 +0100

The effects of different cultures and incubation temperatures on the physical properties of low fat yogurts were investigated. The samples were incubated with exopolysaccharide (EPS)-producing and non-EPS-producing cultures at 37, 42 and 45°C. All measured parameters except firmness were influenced by culture type and incubation temperature. Firmness, G' and G" were maximized at 42°C for both cultures. Increased incubation temperature and EPS culture led to a higher water-holding capacity but lower syneresis, G' and G". The EPS treatment incubated at 37°C showed even lower syneresis than non-EPS treatments incubated at higher temperatures. (Source: International Journal of Dairy Technology)

Influence of starter culture type and incubation temperatures on rheology and microstructure of low fat set yoghurt

International Journal of Dairy Technology — Sun, 02 Aug 2009 23:00:00 +0100

The effects of different cultures and incubation temperatures on the physical properties of low fat yoghurts were investigated. The samples were incubated with exopolysaccharide (EPS)-producing and non-EPS-producing cultures at 37, 42 and 45°C. All measured parameters except firmness were influenced by culture type and incubation temperature. Firmness, G' and G" were maximised at 42°C for both cultures. Increased incubation temperature and EPS culture led to a higher water-holding capacity but lower syneresis, G' and G". The EPS treatment incubated at 37°C showed even lower syneresis than non-EPS treatments incubated at higher temperatures. (Source: International Journal of Dairy Technology)

Research on the chemical composition of Saanen goat colostrum

International Journal of Dairy Technology — Wed, 22 Jul 2009 23:00:00 +0100

Changes in chemical composition in Saanen goat colostrum were studied 3, 12, 24, 48, 72, 120 and 168 h after parturition. The concentrations of dry matter, fat, ash, lactose, protein and IgG at 3 h of lactation were 21.23%, 7.73%, 1.57%, 1.93%, 10.24% and 72.01 mg/mL respectively. Saanen goat colostrum contained very high concentrations of Ca, P and Mg, and very low concentrations of Zn, Fe, Cd, As, Pb and Hg. In Saanen goat colostrum, the total concentrations of 17 amino acids and 8 essential amino acids were 5796.6 mg/100 mL and 2567.7 mg/100 mL respectively. The concentrations of saturated fatty acids were 75.21%, and medium chain saturated fatty acids (C80, C100) were 19.84%. (Source: International Journal of Dairy Technology)

An evaluation of methods for inoculating Listeria monocytogenes into butter for microbiological experimentation

International Journal of Dairy Technology — Wed, 15 Jul 2009 23:00:00 +0100

The behaviour of Listeria monocytogenes Scott A was assessed when inoculated into butter using six different methods. The butter was made using a laboratory-scale butter churn to give consistency in the butter ingredients. No increase in count was seen using the 'stab' or 'contact' methods of butter inoculation. No inoculation method was found to be ideal for every inoculation experiment that may be required. However, it was concluded that the 'mix' and 'bead' methods were most appropriate if the 'cream' inoculation method could not be used. (Source: International Journal of Dairy Technology)

Raw milk and raw milk cheeses as vehicles for infection by Verocytotoxin-producing Escherichia coli

International Journal of Dairy Technology — Tue, 14 Jul 2009 11:20:38 +0100

Raw milk and raw milk cheeses can be a source of food-borne pathogens, including Verocytotoxin (Shiga toxin)-producing Escherichia coli (VTEC/STEC). Outbreaks of VTEC O157: H7 infections have been attributed to the consumption of raw milk and associated dairy products. Although the general prevalence of VTEC O157 in raw milk and raw milk cheeses is low, it can be higher for non-O157 VTEC. The clinical significance of many of these VTEC is unclear, although some are associated with disease. Studies show that E. coli O157 strains can survive the various stages of the cheesemaking process and that raw milk and raw milk cheeses remain a potential vehicle for VTEC infections. (Source: International Journal of Dairy Technology)

Dairy Fats and Related Products

International Journal of Dairy Technology — Sun, 12 Jul 2009 23:00:00 +0100

(Source: International Journal of Dairy Technology)

Milk Processing and Quality Management

International Journal of Dairy Technology — Sun, 12 Jul 2009 23:00:00 +0100

(Source: International Journal of Dairy Technology)

Properties of cholesterol-reduced ice cream made with cross-linked β-cyclodextrin

International Journal of Dairy Technology — Sun, 12 Jul 2009 23:00:00 +0100

This study examined the properties of cholesterol-reduced ice cream stored at [minus]12, [minus]18 and [minus]28°C. Over 90.0% cholesterol was removed, and ice crystal size decreased while viscosity increased as the freezing temperature decreased in the cholesterol-reduced ice cream. The melting time was slightly shorter in the cholesterol-reduced ice cream than in the control. A significant difference was found in the dull colour, and crumbly and unnatural flavour, especially when stored at [minus]28°C, regardless of cross-linked [beta]-cyclodextrin treatment. This study indicated that although some differences were observed, most of the properties of the cholesterol-reduced ice cream were comparable to the control ice cream. (Source: International Journal of Dairy Technology)

Investigation of the possible use of probiotics in ice cream manufacture

International Journal of Dairy Technology — Sun, 12 Jul 2009 23:00:00 +0100

This study attempted to investigate the possibility of using some types of probiotic bacteria in the production of ice cream and was aimed at making a contribution to the manufacture of new functional foods. For this purpose, different cream levels (5% and 10%) and different strains of probiotic bacteria (Lactobacillus acidophilus, Bifidobacterium bifidum and both) were used in ice cream production to determine their effects on the quality of the ice creams in each group. During storage of 1, 15, 30, 45, 60, 75 and 90 days, L. acidophilus, B. bifidum counts and sensory analyses were performed. The results obtained at the end of storage demonstrated that the counts of L. acidophilus and B. bifidum continued to decrease during the storage but all types of ice cream sample seemed to preserve ...

Use of whey and buttermilk based media to obtain biomass of thermophilic LAB

International Journal of Dairy Technology — Sun, 12 Jul 2009 23:00:00 +0100

The growth of commercial strains of thermophilic lactic acid bacteria (LAB) was determined in reconstituted dried whey and buttermilk. Kinetic ([mu], /h and g, h) and growth (N, cfu/mL; X, cell yield and IV , percentual variation) parameters were determined using Elliker (streptococci) and MRS (lactobacilli) broths, and a commercial medium as controls. Cheese whey was the least effective substrate for growing streptococci and lactobacilli strains. However, whey and buttermilk with added yeast extract gave the best performance. These media could be efficient and easily available alternatives for producing industrial biomass of thermophilic LAB. (Source: International Journal of Dairy Technology)

Influence of different exopolysaccharide-producing strains on the physicochemical, sensory and syneresis characteristics of reduced-fat stirred yoghurt

International Journal of Dairy Technology — Sun, 12 Jul 2009 23:00:00 +0100

Reduced-fat stirred yoghurts were prepared by using ropy and nonropy exopolysaccharide (EPS)-producing strains or nonexopolysaccharide-producing strains. Yoghurts were evaluated for pH, titrable acidity, acetaldehyde, whey separation, viscosity, EPS concentration, sensory and microbiological analyses. Determinations of these parameters were made at 1, 7, 14 and 21 days of storage. Reduced-fat yoghurts made with EPS+ strains exhibited lower syneresis and acetaldehyde contents, but higher viscosity than those made with the EPS [minus] strain. Physico-chemical results correlated with the sensory results in that panellists scored the EPS+ yoghurts as having an overall better mouthfeel, but a worse flavour than EPS [minus] yoghurt. (Source: International Journal of Dairy Technology)

Rheological properties of fermented milk produced by a single exopolysaccharide producing Streptococcus thermophilus strain in the presence of added calcium and sucrose

International Journal of Dairy Technology — Sun, 12 Jul 2009 23:00:00 +0100

The effect of calcium supplementation, presence of exopolysaccharides (EPS) and sucrose on the texture of low-fat fermented milk was examined. Reconstituted skim milk (14%) was acidified by 2% glucono-[delta]-lactone (GDL) or a single strain, EPS-producing Streptococcus thermophilus, and incubated at 42°C. The levels of calcium and sucrose addition ranged from 0 to 9 mm and 0 to 45 mm respectively. Compared with acidified milk (GDL), fermented milk containing EPS showed different rheological properties in the presence of added calcium and sucrose. Calcium addition reduced gel characteristics: G', K, and the second maximum of derivative of shear rate-shear stress; while sucrose addition also increased them but subsequently reduced syneresis. Added calcium or sucrose increased gel hysteresi...

Texture of nonfat yoghurt as influenced by whey protein concentrate and Gum Tragacanth as fat replacers

International Journal of Dairy Technology — Sun, 12 Jul 2009 23:00:00 +0100

Seven batches of nonfat yoghurt stabilized with different concentrations of whey protein concentrate (WPC) and Gum Tragacanth (GT) were produced to study the effects of WPC and GT as fat replacers on the rheological properties of yoghurt. By increasing the WPC up to 15 g/L, storage modulus (G'), loss modulus (G") and complex dynamic viscosity ([eta]*) values were increased and sensory impressions of texture and appearance were improved when compared with the control nonfat yoghurt. Addition of gum above 0.5 g/L led the decrease of G', G", [eta]* and resulted in lower scores for sensory attributes than control nonfat yoghurt. (Source: International Journal of Dairy Technology)

The viability of three probiotic organisms grown with yoghurt starter cultures during storage for 21 days at 4°C

International Journal of Dairy Technology — Sun, 12 Jul 2009 23:00:00 +0100

This study investigated the viability of probiotic (Lactobacillus acidophilus LA5, Lactobacillus rhamnosus LBA and Bifidobacterium animalis subsp. lactis BL-04) in milk fermented with Lactobacillus delbrueckii subsp. bulgaricus LB340 and Streptococcus thermophilus TAO (yoghurt [ndash] Y). Each probiotic strain was grown separately in co-culture with Y and in blends of different combinations. Blends affected fermentation time(s), pH and firmness during storage at 4°C. The product made with Y plus B. animalis subsp. lactis and L. rhamnosus had counts of viable cells at the end of shelf life that met the minimum required to achieve probiotic effect. However, L. acidophilus and L. delbrueckii subsp. bulgaricus were inhibited. (Source: International Journal of Dairy Technology)

Shelf life of Turkish whey cheese (Lor) under modified atmosphere packaging

International Journal of Dairy Technology — Sun, 12 Jul 2009 23:00:00 +0100

In this study, the shelf life of Lor cheese stored under different atmosphere compositions was assessed and compared. Lor cheeses were held in four different atmospheres containing: vacuum packaging (VP), 40% CO2/60% N2, 60% CO2/40% N2 and 70% CO2/30% N2 (modified atmosphere packaging). Control cheeses were stored in air. All cheese samples were kept in the refrigerator at 4°C for 45 days and investigated for physicochemical, microbiological and sensory properties. The acidity index value was significantly higher ( P < 0.05) in the control and vacuum packaged samples than in those stored for the same period under CO2. Microbiological results showed that modified atmosphere packaging delayed microbial growth compared with air and VP samples. Of the three modified atmospheres, gas mixtures ...

Occurrence of coagulase-positive Staphylococci, microbial indicators and physical–chemical characteristics of traditional semihard cheese produced in Brazil

International Journal of Dairy Technology — Sun, 12 Jul 2009 23:00:00 +0100

Coagulase-positive Staphylococci and microbial indicators of the 'Requeijão do Norte', a traditional semihard cheese, were surveyed in Brazil. Coagulase-positive Staphylococci were found in quantities of up to 9.4 log cfu/g. The coagulase gene was detected in isolates physiologically classified as coagulase-negative. The SEB and TSST-1 toxins were detected. Salmonella spp. were not detected. High levels of total and fecal coliforms ([ge] 210 MPN/g) and moulds ([ge] 6.48 log cfu/g) were found in most samples. The values of physical[ndash]chemical parameters and water activity showed the greatest variations. These results suggest a possible risk that this cheese may pose to consumers. (Source: International Journal of Dairy Technology)

Occurrence and characterization of Staphylococcus aureus isolated from raw milk for cheesemaking

International Journal of Dairy Technology — Sun, 12 Jul 2009 23:00:00 +0100

Fifty-four samples of raw milk for cheesemaking were tested for the presence of Staphylococcus aureus. Multiplex polymerase chain reactions were performed to identify presumptive isolates and the presence of enterotoxin-coding genes sea-see. The strains were tested for antibiotic resistance. Eighty strains were identified as S. aureus and 31 of these carried one or more enterotoxin genes (sea-see). Resistance to eritromycin, penicillin and ampicillin was widespread among isolates. Staphylococcus aureus in raw milk for cheesemaking may constitute a risk with respect to staphylococcal food poisoning from raw milk products. (Source: International Journal of Dairy Technology)

Behaviour of Listeria monocytogenes inoculated into Minas Frescal cheese made by direct acidification or lactic culture during refrigerated storage

International Journal of Dairy Technology — Sun, 12 Jul 2009 23:00:00 +0100

The behaviour of Listeria monocytogenes Scott A artificially inoculated into Brazilian Minas Frescal cheese manufactured with the addition of a lactic culture or by direct acidification with lactic acid was evaluated at 5 and 10°C for 25 days. In cheese produced with a lactic culture, the counts remained almost unchanged during storage, whereas cheeses produced by direct acidification presented an increase in the counts of 2[ndash]3 log cycles. The profiles of the lactic bacterial counts, associated with those of L. monocytogenes, show a strong influence of the competitive starter culture on the survival of L. monocytogenes. This suggests that the addition of starter culture is an efficient way to control the growth of L. monocytogenes in these products. (Source: International Journal of ...

Chemical and sensory properties of cholesterol-reduced processed cheese spread

International Journal of Dairy Technology — Sun, 12 Jul 2009 23:00:00 +0100

This study examines the property changes of cholesterol-reduced processed cheese spread made by cross-linked [beta]-cyclodextrin. Its composition was similar to that of the control and 91.5% of the cholesterol was removed. Total free amino acids content, gumminess and brittleness scores were significantly higher in cholesterol-reduced cheese spread over all storage periods than those in the control. Yellowness, bitterness and elasticity scores were significantly higher, whereas processed flavour and slimy texture were significantly lower in cholesterol-reduced cheese spread. This study indicates that although some differences were observed, most of the properties were comparable with the control processed cheese spread. (Source: International Journal of Dairy Technology)

Antioxidant activity of Cheddar cheeses at different stages of ripening

International Journal of Dairy Technology — Sun, 12 Jul 2009 23:00:00 +0100

The aim of the study was to evaluate the changes in the antioxidant properties of Cheddar cheese at different stages of ripening using different assays: 2, 2'-azinobis (3 ethyl benzothiazoline)-6-sulphonic acid, 2, 2-diphenyl 1, picryl hydrazyl and superoxide radical scavenging activity. Cheddar cheese was prepared with Lactobacillus casei ssp. casei 300 and Lactobacillus paracasei ssp. paracasei 22 and without adjunct cultures. The antioxidant activity of water-soluble extracts of Cheddar cheese was dependent on the ripening period. The changes in the antioxidant activity were related to the rate of formation of soluble peptides (proteolysis) in all the samples of cheeses up to fourth month of ripening. (Source: International Journal of Dairy Technology)

Characterization of the free fatty acids profile of Pategrás cheese during ripening

International Journal of Dairy Technology — Sun, 12 Jul 2009 23:00:00 +0100

This work compares the free fatty acids (FFA) profiles of Pategrás cheeses manufactured on the pilot scale, with and without the addition of probiotics. Total and FFA in milks and cheeses, respectively, were similar, indicating a nonselective release during ripening. Lipolysis was lo for control cheeses, but somewhat higher for those made in summer, probably because of an elevated psychrotrophic bacterial development. Probiotic bacteria remained highly viable during ripening and had an influence on FFA profiles. A simple sensory profiling of the cheeses showed no differences in flavour and taste and little evidence of treatment effects was found using univariate analysis. Nevertheless, multivariate analysis showed clear differences between probiotic and control products. (Source: Internat...

A new method to estimate the heat treatment of milk and milk-like systems

International Journal of Dairy Technology — Sun, 12 Jul 2009 23:00:00 +0100

A new UV[ndash]Vis absorbance spectrum method was proposed to evaluate the heat treatment of milk and milk-like systems. The method was based on the immediate UV absorbance development when heating amino-sugar mixtures, and validated by correlating the absorbance values of milk-like systems, processed at various temperatures and holding times, with furosine content determined using standardized HPLC analysis. The UV method correlated well with the furosine method under mild heating conditions with R2 = 0.9569 ( P < 0.001) and 0.9594 ( P < 0.01) respectively. This method allowed an efficient discrimination of commercial milk heat treatment. The paper offers the possibility to develop an easy, inexpensive and sensitive way to control the milk protein quality. (Source: International Journal o...

Alkaline phosphatase activity in pasteurized milk: A quantitative comparison of Fluorophos and colourimetric procedures

International Journal of Dairy Technology — Sun, 12 Jul 2009 23:00:00 +0100

Fluorophos and colourimetric procedures for alkaline phosphatase (ALP) testing were compared using milk with raw milk additions, purified bovine ALP additions and heat treatments. Repeatability was between 0.9% and 10.1% for Fluorophos, 3.5% and 46.1% for the Aschaffenburg and Mullen (A&M) procedure and 4.4% and 8.8% for the Scharer rapid test. Linearity ( R2) using raw milk addition was 0.96 between Fluorophos and the Scharer procedure. Between the Fluorophos and the A&M procedures, R2 values were 0.98, 0.99 and 0.98 for raw milk additions, bovine ALP additions and heat treatments respectively. Fluorophos showed greater sensitivity and was both faster and simpler to perform. (Source: International Journal of Dairy Technology)

Effects of starter culture combinations using isolates from traditional cheese on the quality of Turkish white cheese

International Journal of Dairy Technology — Tue, 16 Jun 2009 04:00:00 +0100

Four types of Turkish white cheese with good curd and acid formation properties were produced, one by using commercial starter culture and the other three by using different combinations of isolates from traditional cheese with no starters added. The effects of using these combinations on quality were determined. Starter culture combinations did not influence the chemical properties of cheese significantly. However, one cheese type produced from combinations of isolates of rural cheese was found to be comparable to the samples produced from commercial starter cultures in terms of sensory and microbial quality. This combination could have promise for white cheese production. (Source: International Journal of Dairy Technology)

A review of the chemical, biochemical and antimicrobial aspects of Turkish Otlu (herby) cheese

International Journal of Dairy Technology — Thu, 11 Jun 2009 04:00:00 +0100

Otlu (herby) cheese, a traditional Turkish dairy product, is commonly made in Eastern Anatolia in Turkey. It is consumed in the various parts of Turkey, especially in the eastern and southeastern parts. Its popularity has been increasing because of industrialization of its production. It is manufactured from raw milk, is salty in taste and has a herby intense aroma because of the added herbs. The unusual processing steps of the cheese are that it is firmly filled in a plastic cheese container and stored under the soil during ripening. The flavour becomes highly acceptable after 3 months of ripening. The most common herbs used in the cheese are wild garlic (Allium sp.) but other herbs (Ferula sp., Prangos sp., Thymus sp., Mentha sp., Chaerophyllum macropodum and Silene vulgaris) are also us...

Development of goat cheese whey-flavoured beverages

International Journal of Dairy Technology — Tue, 09 Jun 2009 04:00:00 +0100

Beverages made from goat cheese whey, flavoured with strawberry and peach pulp, were processed and submitted to physicochemical analysis and affective tests. The beverages exhibited similar values with respect to all the analyses of the proximate composition and little variation in pH and titratable acidity during refrigerated storage. They also showed low caloric value. For colour, aroma and consistency acceptability, there was no significant difference ( P > 0.05) among peach and strawberry flavoured samples. The flavour acceptability was higher for the strawberry beverage than for the peach one ( P = 0.05). A positive purchase intent for strawberry flavoured beverage was reported by 76% of the consumers, while 50% affirmed a similar intention for the peach-flavoured product. The beverag...

Characterization of milk coagulating properties from the extract of Withania coagulans

International Journal of Dairy Technology — Tue, 09 Jun 2009 04:00:00 +0100

Plant aspartic proteinases (APs) from Withania coagulans were extracted by using NaCl (0.85%) and were characterized by pH, temperature stability, rennet strength and CaCl2 supplementation. Additionally, the milk-clotting enzyme was partially purified by fractional precipitation with ammonium sulphate and acetone followed by column chromatography of the most active fraction, giving specific activity of 12 307.6 U/mg. The maximum enzyme activity was observed at 4.25 pH and 37°C, which suggested its use in making cheese requiring moderate temperatures (Mozerella, Cheddar). The enzymatic activity increases as the concentration of CaCl2 increases and decreases with the increase of temperature. SDS analysis showed the presence of a single unique band having a molecular weight of 66 KDa. (Sourc...

The effects of butter characteristics on the growth of Listeria monocytogenes

International Journal of Dairy Technology — Sun, 07 Jun 2009 04:00:00 +0100

The behaviour of Listeria monocytogenes was assessed after inoculation into butters made so that they exhibited a range of characteristics. Water droplet size and dispersion throughout the butter affected the ability of L. monocytogenes to grow, its rate of growth and the maximum population level achieved. Listeria monocytogenes was able to grow better in 'coarse' compared to 'fine' butter. Salt in the butter adversely affected growth of L. monocytogenes. However, slow growth was apparent at even higher levels (e.g. 2.1+%) of total salt. Growth of L. monocytogenes in butter at 8°C was comparable to that at 21°C. (Source: International Journal of Dairy Technology)

Erratum