关键词: 牛初乳, 牛常乳, 游离氨基酸, 不溶性蛋白质氨基酸, 对比分析

Abstract: Bovine milk is considered as the raw milk of choice for the production of infant formula. Amino acids in bovine milk, the structural units that make up milk proteins are classified into two groups: free and insoluble-proteome amino acids, which are distributed in different regions (structural domains). In this experiment, we collected bovine colostrum at 0–7 days postpartum and mature milk at 15 days-6 months postpartum for comparative analysis of the insoluble-proteome and free amino acids in them. The results indicated that 9 essential free amino acids and 7 non-essential free amino acids were detected in both milks. Additionally, another non-essential free amino acid was found in bovine colostrum. Among these, 8 essential and 4 non-essential amino acids were found to be significantly more abundant in bovine colostrum than in mature milk (P < 0.05). Among the insoluble-proteome amino acids, 8 essential amino acids and 10 non-essential amino acids were detected simultaneously in both milks. Moreover, the levels of threonine, arginine, serine, cysteine, alanine in bovine colostrum were significantly higher than in mature milk (P < 0.05), while the level of lysine was significantly lower than in mature milk (P < 0.05).

Key words: bovine colostrum, mature milk, free amino acids, insoluble-proteome amino acids, comparative analysis