薏苡仁蛋白质组分研究

目的:对药食两用功能的薏苡仁蛋白质四类组分和氨基酸含量进行分析。方法:采用旋光法、索氏提取法、烘干法、马弗炉法分别进行淀粉、粗脂肪、水分和灰分的测定;采用顺序抽提法依次进行清蛋白、球蛋白、醇溶蛋白和谷蛋白的提取,用Brandford和凯式定氮法进行蛋白质含量分析;采用氨基酸分析仪进行氨基酸含量测定。结果:薏苡仁总蛋白含量为14.17%,其中清蛋白、球蛋白、醇溶蛋白和谷蛋白含量分别为0.20、0.88、6.34和5.30 mg/100mg鲜重,分别占总蛋白质含量的1.43%、6.20%、44.74%和37.38%;薏苡仁粉经酸水解后共检测到15种氨基酸,除Trp外,人体必需氨基酸和半必需氨基酸均有检测到;各氨基酸含量也存在着差异,含量最高的为Glu(3.59 mg/100mg),含量最低的为Me(t0.17 mg/100mg)。结论:薏苡仁蛋白中醇溶蛋白和谷蛋白含量较丰富,为今后进一步开发薏苡仁功能食品提供了理论数据。

Protein Composition Analysis ofCoix Lacryma-Jobi L. var. ma-yuen (Roman.) Stapf Seeds

Objective: To analyze the major proteins and amino acid composition of Coix seeds.Methods: Polarimetry,Soxhlet extraction and drying method were respctively used to analyze the starch,crude fat and water content.Muffle furnace was applied when the ash percentage was measured.Albumins,gulbulins,coixins and glutelins were sequentially extracted and then quantified.Amino acid content was measured by amino acid analyzer Hitachi L 8900.Results: The total protein content of Coix seeds was 14.17%,among which the contents of albumins,globulins,coixins and glutelins were 0.20,0.88,6.34 and 5.30 mg/100 mg fresh weight,accounting for 1.43%,6.20%,44.74% and 37.38% of total protein content,respectively.A total of 15 kinds of amino acid were detected in this research,including all essential and semi-essential amino acids for human beings except for Trp.There was a wide range of amino acid contents,from Glu,the highest composition(3.59 mg/100 mg) to Met,the lowest(0.17 mg/100 mg) one.Conclusions: Coixins and glutelins are the most abundant proteins ofCoix seeds,and this research provides valuable sights for exploring functional food from Coix seeds.