• 한국축산식품학회지
• /
• 제37권6호
• /
• pp.940-947
• /
• 2017

Goat milk has a protein composition similar to that of breast milk and contains abundant nutrients, but its use in functional foods is rather limited in comparison to milk from other sources. The aim of this study was to prepare a goat A2 ${\beta}$-casein fraction with improved digestibility and hypoallergenic properties. We investigated the optimal conditions for the separation of A2 ${\beta}$-casein fraction from goat milk by pH adjustment to pH 4.4 and treating the casein suspension with calcium chloride (0.05 M for 1 h at $25^{\circ}C$). Selective reduction of ${\beta}$- lactoglobulin and ${\alpha}_s$-casein was confirmed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis and reverse-phase high-performance liquid chromatography. The hypoallergenic property of A2 ${\beta}$-casein fraction was examined by measuring the release of histamine and tumor necrosis factor alpha from HMC-1 human mast cells exposed to different proteins, including A2 ${\beta}$-casein fraction. There was no significant difference in levels of both indicators between A2 ${\beta}$-casein treatment and the control (no protein treatment). The A2 ${\beta}$-casein fraction is abundant in essential amino acids, especially, branched-chain amino acids (leucine, valine, and isoleucine). The physicochemical properties of A2 ${\beta}$-casein fraction, including protein solubility and viscosity, are similar to those of bovine whole casein which is widely used as a protein source in various foods. Therefore, the goat A2 ${\beta}$-casein fraction may be useful as a food material with good digestibility and hypoallergenic properties for infants, the elderly, and people with metabolic disorders.

• Asian-Australasian Journal of Animal Sciences
• /
• 제28권8호
• /
• pp.1202-1208
• /
• 2015

The effects of daily dietary Bacillus subtilis (Bs), and adding L-tryptophan, fructan, or casein to fecal fermentation broths were investigated as means to reduce the production of noxious gas during manure fermentation caused by ammonia, hydrogen sulfide ($H_2S$), and 3-methylindole (skatole). Eighty swine ($50.0{\pm}0.5kg$) were equally apportioned to an experimental group given Bs in daily feed, or a control group without Bs. After 6 weeks, fresh manure was collected from both groups for fermentation studies using a $3{\times}3$ orthogonal array, in which tryptophan, casein, and fructan were added at various concentrations. After fermentation, the ammonia, $H_2S$, L-tryptophan, skatole, and microflora were measured. In both groups, L-tryptophan was the principle additive increasing skatole production, with significant correlation (r = 0.9992). L-tryptophan had no effect on the production of ammonia, $H_2S$, or skatole in animals fed Bs. In both groups, fructan was the principle additive that reduced $H_2S$ production (r = 0.9981). Fructan and Bs significantly interacted in $H_2S$ production (p = 0.014). Casein was the principle additive affecting the concentration of ammonia, only in the control group. Casein and Bs significantly interacted in ammonia production (p = 0.039). The predominant bacteria were Bacillus spp. CWBI B1434 (26%) in the control group, and Streptococcus alactolyticus AF201899 (36%) in the experimental group. In summary, daily dietary Bs reduced ammonia production during fecal fermentation. Lessening L-tryptophan and increasing fructan in the fermentation broth reduced skatole and $H_2S$.

• 한국축산식품학회:학술대회논문집
• /
• 한국축산식품학회 2004년도 정기총회 및 제33차 춘계 학술대회
• /
• pp.304-306
• /
• 2004

본 연구는 산양유 ${\beta}$-casein의 효소에 의한 가수분해 특성과 가수분해물의 Angiotensin Converting Enzyme의 저해 효과를 측정하고자 실시하였으며 그 결과는 다음과 같다. 1. 산양유 ${\beta}$-casein은 Mono S HR 5/5 양이온 교환 컬럼에서 분리하여 SDS-PAGE로 순수하게 분리된 것을 확인하였다. 2. 분리된 ${\beta}$-casein을 Trypsin으로 처리하여 가수분해물의 ACE저해 활성을 측정한 결과 가수분해 하지 않은 ${\beta}$-casein은 1.8%의 저해활성을 나타낸 반면, 가수분해한 ${\beta}$-casein은 25.36%의 저해활성을 나타내어 ACE 저해활성이 크게 증가한 것을 확인하였다. 3. 가수분해물의 $IC_{50}$을 측정한 결과 $308.7{\mu}{\ell}/m{\ell}$로 나타났다.

• Journal of Dairy Science and Biotechnology
• /
• 제25권2호
• /
• pp.11-16
• /
• 2007

The nomenclature of genetic variants of casein which is major protein in milk have had a lot of confusion, but now have established. Genetic variants of ${\alpha}_{s1}-CN,\;{\alpha}_{s2}-CN,\;{\beta}-CN,\;{\kappa}-CN$ have reported 8 variants(A, B, C, D, E, F, G, H), 4 variants(A, B, C, D), 13 variants ($A_1,\;A_2,\;A_3,\;A_4$, B, C, D, E, F, G, $H_1,\;H_2$, I), 11 variants(A, B, C, E, $F_1,\;F_2,\;G_1,\;G_2$, H, I, J), respectively. Their data detailed have introduced in several web sites including www.uniprot.org. The studies on genetic variants of casein from Korean native cattle have been reported only ${\beta}-casein\;A_4$ but still not established the protein sequence. The classification and distinct nomenclature of genetic variants of bovine casein were required because the development of milk science and technology have been focused in the region that have to studied biochemically such as functional foods, EMC and GMO et al.

• Journal of Nutrition and Health
• /
• 제38권5호
• /
• pp.373-379
• /
• 2005

This study was performed to determine the effect of isoflavone on bone mineral density and bone mineral content in growing male rats. Twenty male, Sprague-Dawley rats were assigned to groups, that underwent 9 weeks of experi-ental treatment. Animals were assigned to one of two diet groups (casein group or casein supplemented with isoflavones). During 9 week of the study, food consumption was determined every other day through the measurement of total food given subtracting the food uneaten from original amount given. Rats in two experimental groups had similar initial body weights. At the end of experiment, however, the casein group had significantly greater body weights compared to casein supplemented with isoflavones group. It was also observed that the casein group had greater food intake comared to casein supplemented with isoflavones group. The difference in the final body weights of the groups was therefore due to difference in amount of food ingested, but could be due to the effect of isoflavones. Total BMD, spine BMD, and spine BMC per weight and femoral BMD per weight were significantly greater in casein supplemented with isolaones group than casein group. ALP and osteocalcin were significantly greater in the casein-fed group. Crosslink value was significantly lower in the casein supplemented with isoflavones group, All other variables were statistically similar between two groups. Overall, it can be concluded that casein supplemented with isoflavones beneficial for acquisition of bone mineral density and content on growing male rats.

• Journal of Nutrition and Health
• /
• 제29권6호
• /
• pp.578-589
• /
• 1996

This study was performed to invstigate the effect of dietary protein level and source on cadmium intoxicification in rats. Forty-eight male rats of Sprague-Dawley strain weighing 171$\pm$3g were blocked into 8 groups of 6 animals according to body weigth, and were raised for 30days. Eight experimental diets different with cadmium(0ppm, 400ppm)and protein(15%, 40%) levels and protein source[casien, I.S.P.(isolated soy protein)] were given to animals for 30days. Food intake, weight gain, food efficiency ratio, liver weight, kidney weight and femur weight were lower in cadmium added group, and higher in high protein groups(40% protein) than medium protein groups(15% protein). But, dietary protein source had no influence on them. Cadmium concerntration of liver was higher in rats fed casein than I.S.P. groups, and cadmium concentration in intestine was higher in high protein groups. In femur both high protein and I.S.P.diets increased cadmium concentrations. MT concdentrations in liver, kidney and intestine were higher in cadmium added group, and kidney intestine MT concentration were higher in high protein group. Absorption and retention rates of cadmium were lower in rat fed I.S.P. than animal fed casein among medium protein groups and cadmium concentration in blood and liver of I.S.P groups were lower than casein groups. But absorption and retention rates of cadmium were similar in high casein and I.S.P. groups. Renal damage by cadmium administration was not seen in all groups. Absorption rates of zinc and copper competing with cadmium in absorption process were lower in high protein groups than medium protein groups and lower in rats fed I.S.P. than casein. In conclusion, weight gain, F.E.R, and MT concentraion of high protein groups were higher than those of medium protein groups and absorption and retention rates of cadmium were lower in high protein groups. From these results, it was shown that cadmium toxicity was alleviated by high dietary protein. Meanwhile, the effect of dietary source on the cadmium toxicity was different with protein level. In medium protein groups absorption and retention rates of cadmium were much lower in rats fed I.S.P. than casein. In high protein groups, cadmium toxicity was not influenced by protein source and absorption and retention rates of cadmium were not different between casein and I.S.P. groups.

• Asian-Australasian Journal of Animal Sciences
• /
• 제26권6호
• /
• pp.896-904
• /
• 2013

Cattle breeds have a striking effect on milk, including milk composition and technological characteristics. This study aims to compare milk composition, acidification activity, viscosity, milk dispersion system stability and casein molecular weight among three buffalo breeds in China. The technological characteristics of milk produced by three cattle breeds of river buffalo (Murrah), crossbreed 1st generation ($F_1$), crossbreed multiple generation ($F_H$, $H{\geq}3$) buffaloes were investigated. Cattle breeds showed evident effect on milk protein, fat and total solids content, but little effect on most of buffalo casein molecular weight. Milk fat, protein content and the viscosity of buffalo milk from river buffalo were lower than those of $F_1$ and $F_H$, so was the buffer capacity. The viscosity was negatively correlated to temperature and concentration. Results of stability coefficient showed that milk dispersion system had the best dynamic stability characteristics under pH 6.6 and 6 times dilution, while zeta potential of Murrah milk was slightly higher than that of hybrid offspring ($F_1$, $F_H$). SDS-PAGE results showed that buffalo ${\alpha}_s$-casein had a slightly faster mobility than standard ${\alpha}_s$-casein; while buffalo ${\beta}$-casein showed a slightly slower mobility than standard ${\beta}$-casein. There is no clear differences in molecular weight of ${\alpha}_s$-, ${\beta}$-, and ${\kappa}$-casein among Murrah, $F_1$ and $F_H$.

• 한국자원식물학회지
• /
• 제8권2호
• /
• pp.153-157
• /
• 1995

초피(椒皮)나무(Zanthoxylum piperitum DC.)의 embryogenic callus로부터 부정배발생(不定胚發生)에 있어 $NH_4NO_3,\;KNO_3$와 casein hydrolysate의 첨가(添加) 효과(效果)를 알아 보기위하여 본(本) 실험(實驗)을 실시(實施)하였던 바 그 결과(結果)는 다음과 같다. 1. 2,4-D 0.1mg/1가 첨가(添加)된 MT배지(培地)에 $NH_4NO_3$를 3300mg/1 첨가(添加)시킨 배지(培地)에서 부정배발생(不定胚發生)이 가장 양호(良好)하였다. 2. $KNO_3$를 3800mg/1 첨가(添加) 시킨 경우(境遇)에는 MT 기본배지(基本培地)와 2,4-D 0.1mg/1를 첨가(添加)시킨 배지(培地)에서 비교적(比較的) 양호(良好)한 부정배(不定胚)를 발생(發生)시키었다. 3. 2,4-D 0.1mg/1가 첨가(添加)된 MT 배지(培地)에 casein hydrolysate를 700mg/1 첨가(添加)시킨 경우(境遇)에 부정배(不定培) 발생(發生)이 양호(良好)하였으며 2,4-D가 첨가(添加)되지 않는 배지(培地)에서는 부정배(不定培) 발생(發生)이 저조(低調)하였다.

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

• 한국지반공학회논문집
• /
• 제35권1호
• /
• pp.31-42
• /
• 2019

카제인은 우유 속에 약 3% 함유되어 있으면서, 우유에 함유된 전체 단백질의 약 80%를 차지한다. 카제인에 수산화칼슘 및 수산화나트륨 수용액을 섞으면 고결력이 발생하며, 이러한 고결방식은 목재나 건조한 환경에 적용하는 것이 일반적이다. 본 연구에서는 지하수위가 존재하는 토사의 고결을 위해 물에 약한 카제인 고결제의 구성성분을 조절하거나 새로운 성분을 추가하여 내수성을 향상시키고자 하였다. 이를 위해 낙동강모래에 고결제로 가장 많이 사용되는 시멘트뿐 아니라 위스콘신대학에서 제시한 표준 카제인 고결제를 비롯한 다양한 카제인 고결모래 공시체를 제작하였다. 6 종류의 카제인 고결모래 중에서 표준 카제인 고결제에 수산화칼슘을 30% 증가시키고 수산화나트륨을 50% 감소시킨 것이 가장 우수한 강도와 내구성을 나타내었다. 이렇게 개선된 카제인 고결제를 1-4% 혼합하여 만든 공시체의 일축압축강도와 반복건습으로 인한 내구성지수를 시멘트 고결모래 공시체와 비교하였다. 그 결과, 카제인비 4%인 고결모래 공시체의 입축압축강도와 내구성지수는 6,253kPa 및 92%로 일축압축강도 1,500kPa 및 내구성지수 62%인 시멘트비 8%인 고결모래 공시체보다 우수한 것으로 나타났다. 또한, 카제인이 3% 이상 함유된 고결모래 공시체는 반복적인 건습 작용에도 80% 이상의 양호한 내구성을 유지하였다.