牦牛乳的凝乳性质研究  

Coagulation Properties of Yak Milk

作　　者：郑玉才[1] 钟光辉[1] 王永[1] 毛永江[1] 江明峰[1] 彭先文[1] 刘文静[1] 

机构地区：[1]西南民族学院动物科技系,成都610041

出　　处：《西南民族学院学报（自然科学版）》2001年第2期216-220,共5页Journal of Southwest Nationalities College(Natural Science Edition)

基　　金：国家自然科学基金!(39870 60 7);南京农业大学动物生理生化农业部重点开放实验室资助课题

摘　　要：对麦洼牦牛乳的若干凝乳性质进行了分析 ,并与中国荷斯坦牛乳作了比较 .全乳加入凝乳酶后 ,所测定的牦牛个体乳样均能正常凝乳 ,而中国荷斯坦牛乳中有 35%的样品无法凝乳 .降低牦牛乳的pH值或在全乳中加入CaCl2 ( 2 0mg/ 10 0ml乳 )可显著减少凝乳时间 .- 2 0℃保存一个月的牦牛乳样无法正常凝乳 ,提示凝乳与酪蛋白微团的结构有很大关系 .同一时间采集的全奶牦牛与半奶牦牛乳的凝乳时间未见明显差异 ;牦牛乳的凝乳时间与乳的常规营养成分含量及乳蛋白组成之间也未发现明显的相关性 .由于牦牛中未检测到象中国荷斯坦牛那样无法凝乳的个体 ,这一特点使得牦牛乳更适合制作乳酪 .实验还对牦牛凝乳后的酶乳清。Some coagulation properties of Maiwa yak milk were investigated and compared with that of Chinese Holstein. All of the yak milk samples coagulated normally after adding chymosin, while in Chinese Holsteins, 35% of the milk samples failed to coagulate. Coagulation time decreased significantly by lowing the pH of the milk, or adding CaCl 2(20mg/100ml milk)to the whole milk of Maiwa yak. Maiwa yak milk failed to coagulate after storing at -20℃ for approximately one month, suggesting the significance of casein micelle structure in the coagulation process. No significant difference was observed in coagulation time between milks of the total lactating and half lactating yaks, which were in different stages of lactation. No marked relationship was found between coagulation time and protein, fat, lactose contents and relative percentages of the main protein components in yak milk. Yak milk might be more suitable for cheese making due to its good coagulation properties, since there was no poor chymosin coagulation milk like Chinese Holsteins. Protein compositions of whey and casein obtained from coagulation were also analysed by SDS PAGE and alkaline urea PAGE.

关 键 词：牦牛乳 凝乳 凝乳酶 乳酪 电泳分析 

分 类 号：TS252.59[轻工技术与工程—农产品加工及贮藏工程] S823.85[轻工技术与工程—食品科学与工程]