• 한국축산식품학회지
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• 제41권5호
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• pp.855-868
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• 2021

The present study was designed to investigate the effects of protein formula with different casein (C) to whey protein (W) ratios on dispersion stability, protein quality and body composition in rats. Modification of the casein to whey protein (CW) ratio affected the extent of protein aggregation, and heated CW-2:8 showed a significantly increased larger particle (>100 ㎛) size distribution. The largest protein aggregates were formed by whey protein self-aggregation. There were no significant differences in protein aggregation when the CW ratios changed from 10:0 to 5:5. Based on the protein quality assessment (CW-10:0, CW-8:2, CW-5:5, and CW-2:8) for four weeks, CW-10:0 showed a significantly higher feed intake (p<0.05), but the high proportion of whey protein in the diet (CW-5:5 and CW-2:8) increased the feed efficiency ratio, protein efficiency ratio, and net protein ratio compared to other groups. Similarly, CW-2:8 showed greater true digestibility compared to other groups. No significant differences in fat mass and lean mass analyzed by dual-energy x-ray absorptiometry were observed. A significant difference was found in the bone mineral density between the CW-10:0 and CW-2:8 groups (p<0.05), but no difference was observed among the other groups. Based on the results, CW-5:5 improved protein quality without causing protein instability problems in the dispersion.

• Journal of Nutrition and Health
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• 제30권1호
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• pp.3-11
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• 1997

This study was conducted to investigate the effects of protein levels and casein/whey ratios on organ growth and protein metabolism in early weaned rats. Premature rats weaned by the 17th day were fed six semipurified synthetic, isocaloric and gel diets that contained three levels (low, medium and high) and two different combinations(casein/whey ; 80 : 20 or 20 : 80) of milk protein for 8 days. On the 25th day postpartum, frest weigth and DNA, RNA and milk protein contents in brain, liver, kidney and muscle were determined to ascertain organ and cellular growth. Futher, with a view to ascertain protein metabolism and renal functions, serum total protein, $\alpha$-amino N, urea N, and creatinine and creatinine and urinary urea N, creatinine and hydroxproline were determined. Total DNA contents of brain, liver and kidney, which may represent as an index of cell numbers in those organs were significantly decreased in the rats fed diets containing low level protein regardless of casein/whey ratio. However, as fat as the rats fed high protein diets were concerned, their fresh weight, protein contents and GFR of kidney were significantly increased. Furthermore, nitrogen components, $\alpha$-amino N, urea N and creatinie in serum and urine were also increassed. Another observation was that high casein/whey ratio significantly facilitated accumulation of porteins in muscle and kidney and urinary hydorxyproline excretion, not affecting the DNA content of those organs. This study showed that low(8%) or high(32%) contents of protein had less desirable effects either on protein metabolism or on organ cellular growth in prematurely weaned rats, whereas there were no effects on general growth and bone strength.

• 한국축산식품학회지
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• 제43권1호
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• pp.195-195
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• 2023

• 한국식품과학회지
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• 제6권2호
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• pp.75-78
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• 1974

본(本) 실험(實驗)에서는 현재(現在)까지 학문적(學問的)으로 충분(充分)히 밝혀지고 있지 않은, 한우유(韓牛乳)의 이화학적(理化學的) 성질(性質)을 구명(究明)하기 위(爲)하여 한우유(韓牛乳)의 주성분(主成分)을 분석(分析)하고, 또한 DEAE-cellulose를 사용(使用)하여 산(酸) casein, 유청단백질(乳淸蛋白質)을 분별(分別)하여 다음과 같은 결과(結果)를 얻었다. 1. 한우유(韓牛乳)의 비중(比重)은 1.036, 산도(酸度) 0.21, pH는 6.4였고 알콜시험(試驗)에서는 정상(正常)이었다. 2. 한우유(韓牛乳)의 수분함량(水分含量)은 88.39%였고, 무지고형분(無脂固形分) 9.53%였고, 지방(脂肪)은 2.08%, 단백질(蛋白質)은 3.99%, 유당(乳糖)은 4.76%였고 Sialic acid는 0.25%였다. 3. 총단백질중(總蛋白質中) casein이 3.07% 유청단백질(乳淸蛋白質)이 1.13%, lactoglobulin 0.34%, lactalbumin은 0.66%였다. 4. 6M 요소(尿素)를 함유(含有)한 0.005M TCU-buffer를 사용(使用)하여 DEAE-cellulose column에 의(依)해서 한우유(韓牛乳)의 산(酸) casein을 분별(分別)한 결과(結果) 4개(個)의 fraction을 얻었다. 5. 0.04M phosphate-buffer를 사용(使用)하여 DEAE-cellulose column에서 유청단백질(乳淸蛋白質)을 분별(分別)한 결과(結果) 4개(個)의 fraction을 얻어 각(各) fraction의 면적(面積)을 냈다.

• 한국축산식품학회지
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• 제26권3호
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• pp.368-374
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• 2006

We have studied on characterization and cheese making like mineral contents, protein composition and coagulation pattern on equine milk. At first, for contents of mineral on equine milk, It was lower in equine than bovine milk Contents of Na, Mg, P, Ca and K the major minerals, were indicated as 18.3 mg, 0.4 mg, 33.3 mg, 80.9 mg and 134.9 mg respectively by 100 g. In the distribution of nitrogen, the ratio NPN to Nt was indicated as 9.8% while that of bovine milk was 7%. And In NCN, its percentage was indicated as 45.6% shelving that Equine casein was lower than bovine. From these results, equine milk could not be applicable to cheese production since there are no coagulable nitrogen fraction such as ${\kappa}$-casein, as there aye with bovine milk. Equine milk will be more acceptable if we accept that the phylogenic affinity is near to human. It is the same as equine from the view points that monogastric, which did not contain ruminant's casein. For the rennet coagulation, equine milk was different than bovine milk. Equine milk did not coagulated by rennet after the addition of $Ca^{2+}$. But when bovine ${\kappa}$-casein was added in the presece of rennet, and $Ca^{2+}$ to equine milk, coagulation occurred. Such phenomenon was also observed by the use SEM. Verification of ${\kappa}$-casein by SDS-PACE did not existed in equine milk. The Casein of equine milk(54.4%) is similar to human milk in that casein/whey is about 1. For equine milt this can be explained because distance between casein and Ca is great, casein being lower, which result in reaction of casein with $Ca^{2+}$ because it could not activated which lasting time of coagulation is too long.

• Asian-Australasian Journal of Animal Sciences
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• 제27권6호
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• pp.886-897
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• 2014

The aim of the present study was to get a total physical and chemical characterization and comparison of the principal components in Bangladeshi buffalo (B), Holstein cross (HX), Indigenous cattle (IC) and Red Chittagong Cattle (RCC) milk. Protein and casein (CN) composition and type, casein micellar size (CMS), naturally occurring peptides, free amino acids, fat, milk fat globule size (MFGS), fatty acid composition, carbohydrates, total and individual minerals were analyzed. These components are related to technological and nutritional properties of milk. Consequently, they are important for the dairy industry and in the animal feeding and breeding strategies. Considerable variation in most of the principal components of milk were observed among the animals. The milk of RCC and IC contained higher protein, CN, ${\beta}$-CN, whey protein, lactose, total mineral and P. They were more or less similar in most of the all other components. The B milk was found higher in CN number, in the content of ${\alpha}_{s2}-$, ${\kappa}$-CN and ${\beta}$-lactalbumin, free amino acids, unsaturated fatty acids, Ca and Ca:P. The B milk was also lower in ${\beta}$-lactoglobulin content and had the largest CMS and MFGS. Proportion of CN to whey protein was lower in HX milk and this milk was found higher in ${\beta}$-lactoglobulin and naturally occuring peptides. Considering the results obtained including the ratio of ${\alpha}_{s1}-$, ${\alpha}_{s2}-$, ${\beta}$- and ${\kappa}$-CN, B and RCC milk showed best data both from nutritional and technological aspects.

• Journal of Dairy Science and Biotechnology
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• 제19권1호
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• pp.13-21
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• 2001

Milk can be regarded as a complete food, containing protein, fat, lactose, vitamins and minerals. Milk is heated for a variety of reasons. The main reasons are: to remove pathogenic organisms; to increase shelf-life. But, when milk is heated, many changes take place: denaturation of whey proteins and interaction with casein, Maillard browning, losses of vitamin and minerals. The addition of a additive and milk powder to flavor and taste may cause undesirable change of quality during heating milk. The reconstituted milk is the milk product resulting from the addition of water to the dried or condensed form in the amount necessary to re-establish the specified water solids ratio. Therefore, according to the increasement of consumption of processed milk, the necessity for study about the quality of processed milk mixed with reconstituted milk arose.

• 한국축산식품학회지
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• 제18권2호
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• pp.185-191
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• 1998

Human milk and bovine milk in normal stage were fractionated four parts : whey, skimmilk membrane, and casein pellet. The specific activity (nmole / mim / mg protein) and distribution ratio(%) of suborganella marker enzymes in each separated milk fraction were determined. Especially, neutral $Ca^{2+}$-ATPase, acid $Ca^{2+}$-ATPase, NADH-cytochrome C reductase, and acid phosphatase were higher in human milk. However, both $Ca^{2+}$-ATPases were not detected in all fractions of bovine milk. On the other hand, 5'-nucleotidase, phosphodiesterase I, alkaline phosphatase, and $\gamma$-glutamyl transpeptidase activities in bovine milk were higher than in human milk. Most of the marker enzymes were highly distributed in cream fraction of either human milk or bovine milk, and their specific activities were high to 24 fold from 3 fold when compared with that of whole milk. These results suggest that marker enzymes in mammary epitherial cell are transfered into cream fraction by the membrane rearrangement, and different biochemical reaction between human and bovine exists for milk secretion in mammary gland.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제20권3호
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• pp.167-177
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• 2017

Purpose: Breastfeeding is the best way to feed all infants, but not all infants can be (exclusively) breastfed. Cow's milk based infant formula is the second choice infant feeding. Methods: The safety of a new synbiotic infant formula, supplemented with Bifidobacterium lactis and fructo-oligosaccharides, with lactose and a whey/casein 60/40 protein ratio was tested in 280 infants during 3 months. Results: The median age of the infants at inclusion was 0.89 months. Weight evolution was in accordance with the World Health Organization growth charts for exclusive breastfed infants. The evolution of all anthropometric parameters (weight-for-length z score and body mass index-for-age z score) was within the normal range. The incidence of functional constipation (3.2%), daily regurgitation (10.9%), infantile crying and colic (10.5%) were all significantly lower than the reported median prevalence for a similar age according to literature (median value of 7.8% for functional constipation, 26.7% for regurgitation, 17.7% for infantile colic). Conclusion: The new synbiotic infant starter formula was safe, resulted in normal growth and was well tolerated. Functional gastro-intestinal manifestations (functional constipation, regurgitation and colic) were significantly lower than reported in literature. Synbiotics (Bifidobacterium lactis and fructo-oligosaccharides) in cow's milk based infant formula bring the second choice infant feeding, formula, closer to the golden standard, exclusive breastfeeding.