• Asian-Australasian Journal of Animal Sciences
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• 제14권3호
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• pp.351-357
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• 2001

The rapid formation of a cream line cannot be observed in raw goat's milk standing at a low temperature. Although the poor creaming ability of goat's milk has been considered to be due to the small size of milk fat globules and the lack of euglobulin capable of being adsorbed on milk fat globules, there is much left to study. The present work attempted to elucidate a factor for poor creaming ability of goat's milk. The creaming ability of the experimental milks reconstituted from creams and skim milks separated from cow's milk or goat's milk was measured by the volume of the cream layer and the fat content of bottom layer. The polypeptides composition of the P1 the fraction (i.e., the high molecular weight fraction eluted near the void volume obtained by the gel filtration of whey) and milk fat globule membrane prepared from both milks were compared. It was found that the promotion of creaming originated from goat's skim milk was lower than that from cow's skim milk. The P1 fraction in goat's skim milk was less than that in cow's skim milk. The polypeptide (M.W. $4.3{\times}10^4$), found in the P1 fraction of cow's milk was not found in the P1 fraction of goat's milk. It is suggested that the poor creaming ability of goat milk is caused mainly by the difference from cow milk in the amount and the composition of the P1 fraction.

• Journal of Dairy Science and Biotechnology
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• 제24권2호
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• pp.39-45
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• 2006

산양유제품은 산양의 산간 방목지에서 천연의 산야초를 먹는 먹이습성으로 인하여 웰빙식품의 개념으로 뿐만 아니라 산양유 조제식의 형태로 다시 소비되기 시작하고 있다. 우유와 산양유의 조성에는 주요 영양성분의 경우 특별한 차이를 보이지 않는다. 그러나 젖소와 산양의 젖은 케이신 마이셀의 공간구조, 케이신 단백질의 아미노산 조성, 마이셀의 크기, 마이셀의 미네랄 함량 등에 있어서 명백한 차이를 보인다. 산양유제품의 국내생산은 연중 착유가 어려워 소비자에게 연중 공급이 불가능한 문제가 중요한 점으로 대두되고 있다. 그 어려움 속에서 산양유 시장의 확대를 추구하기 위해서는 산양유 제조사들의 집중적인 홍보가 필요하다. 국내 소비시장의 특징은 산양유 소비형태가 주로 신선유로서 소비되며, 발효유로서는 일부만 소비된다는 점이다. 이러한 제품들은 주로 소규모 산양유가공회사에서 생산되며, 대규모 유가공회사에서는 소요량이 많은 산양조제분유 생산에 치중하고 있는 점 또한 특징이라고 할 수 있다. 앞으로 산양유제품의 확대를 위해서는 유가공기술분야의 전문인들에 의해서 한국소비자들에게 적합하지 않은 산양 특유의 불쾌한 냄새와 맛을 제거하는 연구와 기술이 개발되어야 할 것으로 판단된다.

• Journal of Dairy Science and Biotechnology
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• 제31권2호
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• pp.93-98
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• 2013

For purposes of substantiation of organizing measures on industrial processing of goat's and sheep's milk in Mongolia and the production of dairy products we have conducted the studied physico-chemical characteristics of the Mongolian goat's and sheep's milks especially to recognize amino acids, minerals and vitamins in the milk and compare with the Mongolian cow's milk. And also was studied fractional structure of goat's milk whey proteins.

• Journal of Dairy Science and Biotechnology
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• 제34권3호
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• pp.173-180
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• 2016

In many countries, goat milk is an excellent nutrient source and is less allergenic for children and the elderly. The casein composition of goat milk consists largely of ${\beta}$-casein and lower amounts of ${\alpha}_{s1}$-casein, which may interfere with digestion by forming solid curds in the human stomach. Goat milk contains small fat globules and large amounts of medium chain fatty acids for, better digestibility, as well as abundant minerals and vitamins with high absorption rates. Recently, the medical benefits of goat milk in different human disorders have been recognized, leading to an increased interest in developing functional foods with goat milk, particularly for individuals with malabsorption syndrome. However, the physiological and biochemical properties of goat milk are largely unknown. We review the importance of goat milk as a potential functional food by providing scientific evidence confirming its health benefits.

• Journal of Animal Science and Technology
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• 제50권1호
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• pp.111-120
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• 2008

산양유의 비유기간 중 연평균 유지방 함량이 3.88% 이었으며, 동절기(4.2%) 보다 하절기 (3.8%)에 낮았다. 유지방 함유율이 높을수록 총고형분 함량도 비례하여 증가하였다. 산양유 원유를 24시간 냉장저장 하는 동안에 저급 유리지방산(C4:0~C10:0)은 106% 증가하였으며 중급 및 고급 유리지방산(C12:0~C18:1)은 203%로 높은 증가율을 보였다. 균질한 시유에 원유를 첨가하여 반응할 때에 저급 유리지방산은 22% 증가되었으며 중급 및 고급 유리지방산은 199% 증가되었다. Lipase의 종류에 따른 지방분해실험에서 calf lipase는 중급 및 고급지방산 9배 보다 저급지방산은 5.6배로 증가시켰다. 그러나 Candida rugosa lipase와 Pseudomonas fluorescens lipase는 저급 유리지방산이 각각 6배와 14배 증가하고, 중급 및 고급 유리지방산은 각각 34배와 162배 증가하여 중급 및 고급지방산을 더 잘 분해하는 것으로 나타났다. 산양유의 LPL 활성이 높을수록 유리지방산 생성량도 증가되어 유의적 상관관계(r=0.5635)를 보였으며 또한 산양유 이취가 높아지는 상관관계(r=0.5777)를 보였다. 유지방 함량이 낮을수록 LPL 활성은 높아지는 유의적 역 상관관계(r=－0.4627)를 보였다. 산양유의 palmitic acid 함량이 높을 경우 산양유 이취 강도가 증가하는 유의적 상관관계(r=0.7226)를 보였다.

• 한국축산식품학회지
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• 제42권2호
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• pp.210-224
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• 2022

The use of skim milk is a strategy to increase goat milk yogurt acceptability. However, it can negatively affect yogurt rheology because fat plays a vital role in dairy structural integrity. Thus, this study aimed to investigate the effects of fat replacers on the rheological, physical, and sensory parameters of low-fat cupuassu goat milk yogurts during refrigerated storage (28 days). Five goat milk yogurts formulations were carried out: whole yogurt (WY), skim yogurt (SY), skim yogurt with inulin (SIY), skim yogurt with maltodextrin (SMY), and skim yogurt with whey protein (SWY). Treatments were subjected to bacterial counts, chemical composition, pH, water holding capacity, instrumental color and texture, rheological and sensory analyses. All samples showed reducing pH values, water holding capacity, and L^* and b^* value during storage. Regarding texture, the firmness and consistency decreased during storage. On the other hand, the viscosity index significantly increased during refrigerated storage time. Moreover, all treatments exhibited viscoelastic behaviour. In addition, SIY and SMY showed the highest apparent viscosity. Furthermore, SIY, SMY, and SWY formulations exhibited positive sensory scores for appearance, color, aroma, texture, and viscosity. However, the overall acceptability and purchase intention did not differ statistically between WY and the fat-replacement treatments (SIY, SMY, and SWY). These results indicate that fat substitutes improved the quality of skimmed formulations. Thus, inulin and maltodextrin have the potential as functional fat replaces to produce low-fat goat milk yogurts.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1513-1513
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• 2001

Present Food Legislation compels dairy industry to carry out analyses in order to guarantee the food safety and quality of products. Furthermore, in many cases industry pays milk according to bacteriological or/and nutritional quality. In order to do these analyses, several expensive instruments are needed (Milkoscan, Fossomatic, Bactoscan). NIRS technology Provides a unique instrument to deal with all analytical requirements. It offers as main advantages its speed and, specially, its versatility, since not only allows determine all the parameters required in milk analysis, but also allows analyse other dairy products, like cheese or whey. The objective of this study is to develop NIRS calibration equations to predict several quality parameters in goat milk, cheese and whey. Three sets of 123 milk samples, 190 cheese samples and 109 whey samples, have been analysed in a FOSS NIR Systems 6500 I spectrophotometer equipped with a spinning module. Milk and whey were analysed by folded transmission, using circular cells with gold surface and pathlength of 0.1 m, while intact cheese was analysed by reflectance using standard circular cells. NIRS calibrations were obtained for the prediction of chemical composition in goat milk, for fat (r$^2$=0.92; SECV=0.20%), total solids (r$^2$=0.95: SECV=0.22%), protein (r$^2$=0.94; SECV=0.07%), casein (r$^2$=0.93; SECV=0.07%) and lactose (r$^2$=0.89; SECV=0.05%). Moreover, equations have been performed to determine somatic cells (r$^2$=0.81; SECV=276.89%) and total bacteria (r$^2$=0.58; SECV=499.32%) counts in goat milk. In the case of cheese, calibrations were obtained for the prediction of fat (r$^2$=0.92; SECV=0.57), total solids (r$^2$=0.80; SECV=0.92%) and protein (r$^2$=0.70; SECV=0.63%). In whey, fat (r$^2$=0.66; SECV=0.08%), total solids (r$^2$=0.67; SECV=0.19%) and protein (r$^2$=0.76; SECV=0.07%) NIRS equations were obtained. These results proved the viability of NIRS technology to predict chemical and microbiological parameters and somatic cells count in goat milk, as well as chemical composition of goat cheese and whey.

• Asian-Australasian Journal of Animal Sciences
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• 제6권4호
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• pp.555-559
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• 1993

Studies at freezing point depression (FPD) for goat milk are described in this paper. The 432 samples of raw goat milk collected in a period of two years and analysed by the use of an electronic cryoscope gave a mean value of FPD: $-0.565{\pm}0.01^{\circ}C$. Statistical significant differences were found between the morning and evening milk. The evening milk showed better quality considering the lactose and others dissolved solutes. Among the Brown, Saanen and Anglo-nubian goats, the greatest increase in FPD, occurred in the Anglo-nubian breed. The statistical analysis revealed a significant breed difference (p<0.05), when climate variation was observed. The superior and inferior values found to the FPD of the caprine milk (-0.545 to $-0.585^{\circ}C$), is important in establishing regional rules, to improve the quality control criteria and legal interpretation of standards found in the pertinent legislation. The results are also important to improve herd management so that one can increase the animal production which will affect the technological composition, and the nutritional characteristics of the resultant products.

• Asian-Australasian Journal of Animal Sciences
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• 제15권7호
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• pp.963-967
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• 2002

Eighteen crossbred goats were selected from the Institute's goat herd to determine the changes in hormones, blood metabolites and yield and composition of milk during lactation. The blood and milk samples were collected from each goat in a heparinized vacutainer tubes at fortnightly interval for a period of 150 days. In milk samples, fat, protein and lactose contents were estimated while in blood plasma hormones viz., prolactin, GH, cortisol, insulin, $T_4$ and $T_3$ were measured using radioimmunoassay methods. The plasma concentration of prolactin, GH and cortisol were high during early lactation when the goats acquired peak milk yield. During remainder of lactation their concentration varied. The high NEFA concentration during early lactation indicated mobilization of body reserves as the body weights also decrease during early lactation. However, with the advancement of lactation, the body weights of the goats and the concentration of NEFA declined which indicated utilization of NEFA for energy yielding purposes in addition to fatty acid synthesis. The ambient temperatures did not influence plasma concentration of prolactin, GH, insulin, $T_3$ and $T_4$ during the lactation cycle. The fat content of milk varied significantly (p<0.01) but protein and lactose content of milk remains unchanged during different stages of lactation. Growth hormone was positively correlated with insulin (p<0.05) during lactation while prolactin had a positive correlation with lactose and plasma NEFA (p<0.01) and negative correlation with $T_3$ (p<0.05).

• Asian-Australasian Journal of Animal Sciences
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• 제26권7호
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• pp.911-915
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• 2013

The aim of this study was to investigate allele frequencies at the CSN1S2 locus in two Chinese dairy goat breeds and the effects of its variation on dairy goat economic traits. Seven hundred and eight goats from Xinong Saanen (XS, n = 268) and Guanzhong (GZ, N = 440) breeds were selected. The milk samples of 268 XS goats were collected during the middle of lactation, body size parameters (708 goats) and daily milk yield (202 goats) were registered. The RFLP (restriction fragment length polymorphism) and SSCP (single strand conformation polymorphism) were used to detect the polymorphisms in CSN1S2. The Hardy-Weinberg (HW) equilibrium and the associations between body size, milk yield and composition and the genotypes were calculated. The results revealed that only A and F CSN1S2 alleles were found in the two Chinese dairy goat breeds. Allelic frequencies of A and F were 0.795, 0.205 and 0.739, 0.261 in Xinong Saanen and Guanzhong population respectively. Xinong Saanen breed was in Hardy-Weinberg equilibrium, while Guanzhong breed deviated from Hardy-Weinberg equilibrium (p<0.05). The association of polymorphism with economic traits indicated that the goats with FF genotype have higher milk fat and total solid concentration than those with AA and AF genotypes (p<0.05).