牦牛奶渣营养成分分析

Nutritional evaluation in Yak milk residue

采用凯氏定氮法、索氏脂肪抽提法、高效液相色谱法、SDS-PAGE法,对牦牛奶渣中蛋白质、脂肪、氨基酸含量进行了测定,并分析了其蛋白质组分。结果表明,奶渣中脂肪和蛋白质含量分别为1.69%与63.92%;奶渣中含有16种水解氨基酸,必需氨基酸占总氨基酸含量的46.76%,其中Asp、Phe、Lys在牦牛奶渣中所占的比例显著高于其在牦牛乳中所占的比例;牦牛奶渣蛋白质组分以CN为主,其中CN相对含量为77.56%。结果提示,牦牛奶渣含有人体所必需氨基酸,并具有高蛋白、低脂肪的特点,可作为高原地区牧民易于保存的优质蛋白来源。

The protein, fat, amino acid and protein components in Yak milk residue（YMR） were determined by using Kjeldahl method, Soxlet＇s extraction, high-performance liquid chromatography and SDS-PAGE methods. The results showed that the content of fat and protein were 1.69% and 63.92%, respectively. The YMR contained 16 kinds of hydrolytic amino acids, essential amino acids accounting for 46.76% in total amino acids. In addition, the content of Asp, Phe, Lys were significantly higher than those in Yak milk. CN was found to be the major kind of the protein components, reaching to the level of 77.56%. The results suggest that due to the characteristics of low fat, high protein and essential amino acids level, YMR could be considered as an excellent easily preserved protein source for local farmers.