• Journal of Dairy Science and Biotechnology
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• v.28 no.1
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• pp.17-28
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• 2010

A substantial body of evidence has emerged over the last decade in support of the novel concept that dietary calcium and dairy foods play an important role in regulating energy metabolism and thereby promote healthy weight management and reduce obesity risk. This concept has been demonstrated in experimental animals studies, cross-sectional and prospective population studies and a number of randomized clinical trials. Notably, the effects of dairy foods in weight management are more consistent than the effects of supplemental calcium across clinical trials, and calcium per se is responsible for approximately 40-50% of the effects of dairy. The calcium component is only effective in individuals with chronically low calcium intake, as it serves to prevent the endocrine response to low calcium diets which otherwise favors adipocyte energy storage; calcium also serves to promote energy loss via formation of calcium soaps in the gastrointestinal tract and thereby reduce fat absorption. The calcium-independent anti-obesity bioactivity of dairy resides primarily in whey. The key components identified to date are leucine and bioactive peptides resulting from whey protein digestion. The high concentration of leucine in whey stimulates a repartitioning of dietary energy from adipose tissue to skeletal muscle where it provides the energy required for leucine-stimulated protein synthesis, resulting in increased loss of adipose tissue and preservation of skeletal muscle mass during weight loss. Finally, dairy rich diets suppress the oxidative and inflammatory responses to obesity and thereby attenuate the diabetes and cardiovascular disease risk associated with obesity.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.2
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• pp.297-304
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• 2006

Insulin-like growth factor-I (IGF-I) rich fraction, collected components between 1 kDa and 30 kDa, was fractionated from bovine colostral whey using an ultrafiltration membrane. IGF-I was confirmed in the collected IGF-I rich fraction by both SDS-PAGE and Western blotting. The concentration of IGF-I in the IGF-I rich fraction was 10 ng/mg protein. One hundred microliters of the reconstituted IGF-I rich fraction was intraperitoneally injected into ICR male mice for 2 weeks at 24 h intervals. The functions of peritoneal macrophages, including phagocytosis, interleukin (IL)-6 and tumor necrosis factor (TNF)-${\alpha}$ production, and nitric oxide and hydrogen peroxide production, were enhanced significantly by the administration of the IGF-I rich fraction in a dose-dependent manner (p<0.01). The proliferation of Concanavalin (Con) A-stimulated and Lipopolysaccharide (LPS)-stimulated splenocytes was also determined to have been enhanced significantly by the administration of the IGF-I rich fraction in a dose-dependent manner (p<0.01). Our results indicate that the administration of IGF-I rich fraction obtained from bovine colostral whey enhances both innate and acquired immunity for ICR male mice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1128-1134
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• 1997

Lactobacillus helveticus was inoculated to the fermentation liquid containing skin milk powder(SMT) plus soymilk, SMP plus isolated soybean protein(ISP), SMP plus ISP plus whey powder(WP) to increase the nutritional and economic value of commercial soy yogurt. The yogurt fermented with soymilk and SMP showed the lower acid production than of SMP and had significant beany flavor in the product. The yogurt prepared with ISP and SMP showed the higher cell number and lower acid production than that of SMP. Also, the partial substitution of SMP with ISP over 6%(w/w) produced less acceptable product due to gel production. The yogurt prepared by the partial substitution of SMP with ISP, WP and SMP showed the higher cell number and lower acid production than that of SMP and not bring about gel formation unlike the case of ISP. Sensory properties of yogurt substituted SMP with ISP and WP(38:62 mixture) below 4% were not significantly different from that of SMP and the sample containing the mixture over 6% and 0.067% artificial flavor showed lower sensory score due to beany taste than that of SMP. But increase of yogurt flavor up to 0.1% resulted in significantly high score in organoleptic acceptability. The separation of water occured in yogurt prepared by the combined mixture of ISP, WP and SMP, and this problem could be resolved by addition of Na-alginate and PGA at the concentration of 0.1%(w/w).

• Food Science of Animal Resources
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• v.29 no.5
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• pp.633-639
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• 2009

The principal objective of the current study was to prepare low molecular weight peptides from milk proteins using enzymatic hydrolysis techniques, in an effort to assess the antioxidant activity of these peptides. The casein and whey proteins isolated from fresh milk were treated with several proteolytic enzymes, such as chymotrypsin, pepsin, and trypsin and the resulting low molecular weight peptides were collected by TCA precipitation. Their identity was confirmed by SDS-PAGE analysis. The hydrolysis experiments indicated that whey protein treated with chymotrypsin displayed the highest degree of protein hydrolysis. The antioxidant activity of milk protein hydrolysates was determined by measuring the ABTS-radical scavenging activity. The results of these experiments showed that hydrolysis of the milk protein was effective in increasing their antioxidant activities. Especially, the tryptic digested casein displayed the highest radical scavenging activity (80.7%). The hydrolyzed low molecular weight milk protein was isolated using an ultrafiltration membrane. The casein hydrolysate passed through a membrane with molecular weight cut-off (MWCO) of 3 kDa displayed the strongest antioxidant activity.

• Journal of Dairy Science and Biotechnology
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• v.32 no.2
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• pp.93-100
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• 2014

In general, whey obtained from various cheese batches is being reused, so as to improve the texture and to increase the yield and the nutrient value of the various final milk-based products. In fact, re-usage of whey proteins, including whey cream, is a common and routine procedure. Unfortunately, most bacteriophages can survive heat treatments such as pasteurization. Hence, there is a high risk of an increase in the bacteriophage population during the cheese-making process. Whey samples contaminated with bacteriophages can cause serious problems in the cheese industry. In particular, the process of whey separation frequently leads to aerosol-borne bacteriophages and thus to a contaminated environment in the dairy production plant. In addition, whey proteins and whey cream reused in a cheese matrix can be infected by bacteriophages with thermal resistance. Therefore, to completely abolish the various risks of fermentation failure during re-usage of whey, a whey treatment that effectively decreases the bacteriophage population is urgently needed and indispensable. Hence, the purpose of this review is to introduce various newly developed methods and state-of-the-art technologies for removing bacteriophages from contaminated whey and whey products.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.10
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• pp.1421-1424
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• 2005

The aim of this study was to evaluate the effect of two diets different in crude fibre content and ingredients on performance and on caecal characteristics of rabbits around weaning. Thirty litters from thirty New Zealand White does were divided at Day 18 in two groups fed, respectively, a low fibre concentrate (LFC, consisting mainly of soybean meal, delactated whey, barley) from Day 18-28 followed by a creep feed (CF, consisting mainly in alfalfa meal, barley and wheat bran) from Day 29-32, and a CF from Day 18-32. After weaning (32 days) both groups were fed the CF ad libitum for two weeks. During the pre-weaning period, mortality, milk intake and solid feed intake (from Day 20) were recorded daily, while the live weight of kits was recorded twice, at 18 and 32 days. At day 28, one rabbit/litter was slaughtered in order to obtain data on caecal content characteristics. After weaning, the rabbits were located in collective cages, feeding ad libitum CF; feed intake, live weight and mortality were recorded weekly for two weeks. During the preweaning period, there were no differences between the groups in milk and solid feed intake and, by consequence, in live weight at weaning; instead, the mortality was higher (12.5 vs 4.5%) for the group (A) that changed diet at 28 days. Group A showed also a higher caecal pH (6.12 vs. 5.72), propionate to butyrate ratio (0.73 vs. 0.46), ammonia content (9.3 vs. 7.1 mmol/l), but a lower total volatile fatty acid content (66.8 vs. 82.1 mmol/l) than B Group, probably due to the dried milk whey in the concentrate. After weaning, there were no significant differences between the two groups. The authors concluded that the use of a low fibre concentrate for suckling rabbits is not recommended.

• Food Quality and Culture
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• v.1 no.1
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• pp.22-26
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• 2007

This study was performed to determine the feasibility of developing a healthy yogurt using tofu whey concentrates separated by nanofiltration (NF). The curd yogurt was prepared from whole milk with added skim milk powder, in which the NF powder was substituted at 0, 6.25, 12.5, or 25% for the skim milk powder. The quality characteristics were evaluated for pH, titratable acidity, viscosity, color, and viable cell counts. There were no significant differences in pH or titratable acidity between the control (yogurt with added skim milk powder only) and the yogurts with added NF powder, after 24 hr of fermentation at $37^{\circ}C$. The apparent viscosities of the yogurts with added NF powder were higher ($3,197{\sim}3,574\;cps$) than that of the control yogurt (3,196 cps). Lightness decreased, while yellowness increased, as the amount of NF powder increased. Sensory evaluations showed that the NF powder could be substituted for the skim milk powder at 6.25% without lowering the yogurt quality.

• Journal of Animal Science and Technology
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• v.58 no.3
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• pp.10.1-10.10
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• 2016

Background: Airag, alcoholic sour-tasting beverage, has been traditionally prepared by Mongolian nomads who naturally ferment fresh mares' milk. Biochemical and microbiological compositions of airag samples collected in Ulaanbaatar, Mongolia and physiological characteristics of isolated lactic acid bacteria were investigated. Methods: Protein composition and biochemical composition were determined using sodium dodecyl sulfate-gel electrophoresis and high performance liquid chromatography, respectively. Lactic acid bacteria were identified based on nucleotide sequence of 16S rRNA gene. Carbohydrate fermentation, acid survival, bile resistance and acid production in skim milk culture were determined. Results: Equine whey proteins were present in airag samples more than caseins. The airag samples contained 0.10-3.36 % lactose, 1.44-2.33 % ethyl alcohol, 1.08-1.62 % lactic acid and 0.12-0.22 % acetic acid. Lactobacillus (L.) helveticus were major lactic acid bacteria consisting of 9 isolates among total 18 isolates of lactic acid bacteria. L. helveticus survived strongly in PBS, pH 3.0 but did not grow in MRS broth containing 0.1 % oxgall. A couple of L. helveticus isolates lowered pH of skim milk culture to less than 4.0 and produced acid up to more than 1.0 %. Conclusion: Highly variable biochemical compositions of the airag samples indicated inconsistent quality due to natural fermentation. Airag with low lactose content should be favorable for nutrition, considering that mares' milk with high lactose content has strong laxative effect. The isolates of L. helveticus which produced acid actively in skim milk culture might have a major role in production of airag.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.36-42
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• 2009

This study was performed to develop low-fat/reduced-salt sausages (LFRSS; <3% fat and <1.5% salt) containing milk protein (whey protein concentrate, WPC, or sodium caseinate, SC) that showed the similar cooking yield and textural characteristics to those of regular-fat/salt sausage control (RFC; 20% fat and 1.5% salt) or low-fat sausage control (LFC; <3% fat and 1.5% salt). Low-fat sausages (LFS) were formulated with a 2.5% fat replacer (konjac flour:carrageenan:soy protein isolate=1:1:3) and various salt levels (0.75, 1.0, 1.25, and 1.5%). LFS had differences in color and expressible moisture (EM, %) values as compared to those of RFC. A minimum salt level of 1% and addition of nonmeat proteins were required to manufacture LFRSS that have similar characteristics to those of RFC. However, LFS with 2% milk proteins reduced the hardness and gumminess as compared to LFC. These results indicated that 1% milk protein in combined with 1% salt was a proper level for manufacturing of LFRSS.

• Korean Journal of Food Science and Technology
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• v.24 no.3
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• pp.209-214
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• 1992

In order to save foreign currency and to domesticize the dairy products, various fresh cheeses and whey drinks were developed and some physicochemical, microbiological and sensory evaluation were performed. The yield of fresh cheese was 22.3%, while that of whey 77.7%. The pH-values of fresh cheeses were $5.90{\sim}6.49$, while those of whey drinks $6.07{\sim}6.49$, and fermented whey drinks $3.97{\sim}4.91$. The acidities of fresh cheeses were $0.09{\sim}0.26%$, while those of whey drinks $0.09{\sim}0.36%$. The contents of solid substances, protein and lactose in fresh cheeses were $25.67{\sim}34.18%$, $7.45{\sim}9.11%$ and $3.61{\sim}4.14%$, while those of whey drinks $7.39{\sim}7.70%$, $0.88{\sim}0.94%$ and $4.93(\sim}6.17%$, respectively. The lactic acid contents of whey drinks varied from $0.01{\sim}0.38%$, where the content in the fermented sample was the highest. The general colony counts of fresh cheeses were $0{\sim}30/g$, while those of whey drinks $0{\sim}80/ml$. The psychrotrophs counts of fresh cheeses were $0{\sim}20/g$, while those of whey drinks $0{\sim}60/ml$. Lactic acid bacterial counts in both products were not detected except for $97{\sim}401{\times}10^8/ml$ in fermented whey drinks. E. coli and fungi were not detected in both products. In sensory evaluation of both products, the strawberry added fresh cheese was the best of fresh cheeses, while the garlic added fresh cheese was the worst. Pure whey drink was the best of whey drinks, while the ginseng added whey drink was the worst.