青稞中氨基酸含量的测定分析及评价

Determination of amino acids in Hulless barley

目的研究测定青稞中氨基酸含量的方法,并进行氨基酸评分。方法样品用含0.05%巯基乙酸的盐酸溶液水解提取,样液经定容、过滤、真空浓缩、复溶、过膜,采用水解氨基酸色谱柱PH(4.6 mm×60 mm, 3μm)分离后,氨基酸分析仪测定,外标法定量。结果本实验应用含巯基乙酸的盐酸水解液,对样品进行水解的同时有效防止了蛋氨酸的氧化,方法的回收率为93.2%～96.7%,相对标准偏差小于2.9%(n=6)。赖氨酸作为谷物限制性氨基酸,在青稞中含量高达0.367 g/100 g,其赖氨酸评分(AAS)为62.4,高于小麦、粳米、玉米、小米的相应评分。结论该方法准确快速、重现性好,适用于青稞中氨基酸含量测定方法的要求。

OBJECTIVE A new method for the determination of 16 amino acids in Hulless barley which were planted in the Tibetan plateau of China was established by the amino acid analyzer(AAA),and the amino acid was graded.METHODS The samples were subjected to hydrolysis by the hydrochloric acid solution containing 0.05%thioglycolic acid,and were carried out by AAA and hydrolyzed amino acid column PH(4.6 mm×60 mm,3μm).The external standard method was used for quantitative analysis.RESULTS This hydrolysis pretreatment process could effectively prevent oxidation of methionine.The recoveries were 93.2%-96.7%,and the relative standard deviations were no more than 2.9%(n=6).As the cereal-restricted amino acid,Hulless barley restricted amino acid lysine was the content of up to 0.367 g/100 g,and the lysine score(AAS)was 62.4,which was better than the corresponding scores of wheat,glutinous rice,corn and millet.CONCLUSION The method is accurate,and has good repeatability which could meet the requirements for determination of 16 amino acids in Hulless barley.