牛乳基和羊乳基奶粉中16种氨基酸含量的测定及比较

Determination and Comparison of 16 Kinds of Amino Acid Contents in Cow Milk-based Milk Powder and Goat Milk-based Milk Powder

目的:对乳粉中氨基酸分析的水解方法进行研究,比较牛乳基奶粉和羊乳基奶粉中氨基酸的含量。方法:样品用含巯基乙酸的盐酸溶液水解提取,经定容、过滤、真空浓缩、复溶、过膜后,用氨基酸分析仪测定,外标法定量。结果:应用含0. 05%巯基乙酸的盐酸水解液对奶粉样品进行水解的同时有效防止了蛋氨酸的氧化,相对氧化水解方法节省前处理时间,方法的回收率为94%~97%,相对标准偏差小于3. 0%。通过对牛乳基和羊乳基奶粉样品中的16种氨基酸分析,牛乳基奶粉中赖氨酸含量略高于羊乳基奶粉,其他相应氨基酸含量不存在显著性差异。结论:该方法准确快速、重现性好,适用于奶粉中氨基酸含量分析的检测要求。

[Objective] A new Method for the determination of 16 kinds of amino acids in milk powder was established with the amino acid analyzer(AAA).The contents of the amino acids in cow milk-based milk powder and goat milk-based milk powder was compared.[Method] The sample was hydrolyzed with a hydrochloric acid solution containing thioglycolic acid,and subjected to constant volume,filtration,vacuum concentration,reconstitution,membrane,and then were determined by AAA.The external standard Method was used for quantitative analysis.[Result] The hydrochloric acid containing 0.05 % thioglycolic acid was used to hydrolyze the milk powder sample,which effectively prevented the oxidation of methionine,and saved the pretreatment time.The recovery rate of the Method was 94 %~97 %.The deviation was less than 3.0 %.Through the analysis of 16 kinds of amino acids of cow milk-based milk powder and goat milk-based milk powder samples,the content of lysine in cow milk-based milk powder was slightly higher than that of goat milk-based milk powder,and there was no significant difference in other corresponding amino acid contents.[Conclusion] The Method is accurate,rapid,and is suitable for the detection requirements of amino acid content analysis in milk powder.