采用全自动氨基酸分析仪分别测定人乳、牛乳、羊乳氨基酸组成.应用模糊识别法和氨基酸比值系数、氨基酸比值系数分等指标全面评价3种乳乳清部分营养价值.采用傅里叶红外光谱的酰胺Ⅰ带和酰胺Ⅲ带测定3种乳中乳清蛋白的天然二级构象.结果表明:羊乳乳清部分必需氨基酸与总氨基酸比值为0.450,全鸡蛋蛋白贴近度与联合国粮食及农业组织/世界卫生组织贴近度分别为0.9197、0.9250,2种氨基酸比值系数分分别为68.47、76.56,在氨基酸营养评价上营养价值较高.羊乳乳清蛋白二级结构中的α-螺旋比例为20.26%,与人乳的27.37%更为接近,一定程度上更利于人体吸收.因此,羊乳是相比牛乳较好的婴幼儿功能性食品原料.%This study adopted an automatic amino acid analyzer to measure the amino acid composition of whey proteins in human milk, bovine milk and goat milk. The nutritional value was comprehensively evaluated by the fuzzy recognition method based on ratio coefficient of amino acid (RCAA) and score of ratio coefficient amino acid ratio coefficient score (SRCAA). The secondary structure of whey proteins was measured based on the amide Ⅰ and amide Ⅲ bands in Fourier transform infrared (FTIR) spectra. Results showed that the ratio of essential amino acids to total amino acids (EAA/TAA) in goat whey proteins was 0.450, showing a 0.919 7 and 0.925 0 similarity to whole egg protein and United Nations Food and Agriculture Organization/World Health Organization (FAO/WHO) reference protein, respectively, and the SRCAA values were 68.47 and 76.56, respectively in the two patterns indicating high nutritional value. The proportion of α-helix structure in goat whey proteins was 20.26%, which is much closer to that of human whey proteins (27.37%) indicating greater ease of absorption by the human body. Therefore, goat milk is a better source of functional foods for infants and young children.
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