食品科学 ›› 2017, Vol. 38 ›› Issue (24): 107-112.doi: 10.7506/spkx1002-6630-201724017

• 成分分析 • 上一篇    下一篇

人乳、牛乳、羊乳中乳清部分氨基酸组成及乳清蛋白中蛋白质二级结构的对比

张熙桐,关博元,孔繁华,刘彪,陶冬冰,武俊瑞,岳喜庆   

  1. (1.沈阳农业大学食品学院,辽宁?沈阳 110866;2.内蒙古伊利实业集团股份有限公司,内蒙古?呼和浩特 010050)
  • 出版日期:2017-12-25 发布日期:2017-12-07
  • 基金资助:
    “十二五”农村领域国家科技计划课题(2013BAD18B03-02)

Comparative Study of Amino Acid Composition and Secondary Structure of Whey Proteins in Human Milk, Cow Milk, and Goat Milk

ZHANG Xitong, GUAN Boyuan, KONG Fanhua, LIU Biao, TAO Dongbing, WU Junrui, YUE Xiqing   

  1. (1. College of Food, Shenyang Agricultural University, Shenyang 110866, China;2. Inner Mongolia Yili Industrial Co.Ltd., Hohhot 010050, China)
  • Online:2017-12-25 Published:2017-12-07

摘要: 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0.919?7、0.925?0,2?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。

关键词: 氨基酸, 营养评价, 乳清蛋白, 傅里叶变换红外光谱, 二级结构

Abstract: 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.

Key words: amino acid, nutritional evaluation, whey protein, Fourier transform infrared (FTIR), secondary structure

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