粮食游离氨基酸含量测定方法精密度及回收率分析

根据粮食中游离氨基酸的氨基与水合茚三酮反应生成蓝紫色化合物，采用比色法测定粮食中游离氨基酸含量。采用二因素随机区组试验设计和生物统计软件SSPSS11．5的单因素方差分析表明，本方法测定的粮食种类间游离氨基酸含量次序为大豆〉小麦=玉米〉糙米〉大米，其中大米游离氨基酸含量最低。该方法非常灵敏，加入标准亮氨酸2mg的回收率对谷物大于58．8％，对大豆大于20．2％，精密度小于20％。

Precision and Percent Recovery on the Determination Method of Free Amino Acids in Grains

All the alpha-amino acids in grains could react with ninhydrin into blue-purple compounds, and is quantitatively de- termined by colorimetry.This paper adopted a randomized block experimental design of two factors like grain species and analy- sers, and analyzed the experimental data by one-way ANOVA in biostatistic software SPSS 11.5 version.There was no difference in grain free amino-acid contents （FACC） among different analysers,but significant difference was existed among grain species. The contents of free amino acids in soybean ,wheat,brown rice, and milled rice were successive significantly lowered.The FACC in shelled corn was similar with that of wheat.The method for FACC determination has a precision below 20%,with high sensitivi- ty.The percent recovery with addition of 2 mg Leucine was 58.8% and 20.2% respectively for cereal and soybean.