新疆、内蒙古地区马乳及发酵酸马乳中氨基酸分析与营养评价

Amino Acid Analysis and Nutritional Evaluation of Mare Milk and Traditional Fermented Mare Milk in Xinjiang and Inner Mongolia

为探讨我国西部牧区(新疆、内蒙古)马乳与传统发酵酸马乳的氨基酸组成及营养评价,在新疆、内蒙古两地主要牧区采集马乳及传统发酵酸马乳共40份,采用氨基酸自动分析仪和高效液相色谱法测定乳中游离氨基酸和水解氨基酸的组成与含量,并进行差异性分析和营养评价。结果表明:新疆、内蒙古地区马乳氨基酸总量无显著差异(P>0.05),两地马乳经发酵后游离氨基酸含量普遍显著升高(P<0.05),且生成了包括γ-氨基丁酸、β-氨基异丁酸、γ-羟基赖氨酸等在内的多种具有特殊生理活性的氨基酸;新疆马乳经发酵后甜味氨基酸含量明显升高,呈味氨基酸总含量明显高于鲜马乳(P<0.05),发酵对马乳风味改进贡献明显;新疆、内蒙古马乳及酸马乳的必需氨基酸指数均大于95,两地发酵后的酸马乳各营养评价指标均高于鲜马乳。

The aim of this paper is to explore the amino acid composition and nutritional evaluation of mare milk and traditional fermented mare milk in two pasture areas of western China. In this study, 40 samples of mare milk and traditional fermented mare milk were collected in the main pastoral areas of Xinjiang and Inner Mongolia. An amino acid automatic analyzer and high performance liquid chromatography were used to determine the composition and content of free amino acids and hydrolyzed amino acids in the samples. The obtained data were analyzed using analysis of variance(ANOVA) and nutritional evaluation was performed. The results showed that there was no significant difference in the total amino acid of mare milk in both areas(P > 0.05);the free amino acid contents of two fermented mare milk samples were generally significantly increased relative to their unfermented counterparts(P < 0.05), and new amino acids with special physiological activities were produced such as gamma-aminobutyric acid(GABA), beta-aminoisobutyric acid(BAIBA) and gammahydroxylysine;the content of sweet amino acid Xinjiang mare milk was significantly increased after fermentation, and the total amino acid content was higher than in fresh mare milk, indicating that fermentation helped improve the flavor of mare milk;the essential amino acid index values of fresh and fermented mare milk from the two areas were all greater than 95, indicating that both fresh and fermented mare milk were high-quality protein sources. Moreover, the nutritional evaluation of fermented mare milk was higher than fresh mare milk in each area.