稻米蛋白质测定方法的比较与分析

分别利用凯氏定氮法和双缩脲法对10个稻米样品的蛋白质含量进行测定。比较发现,两种方法的测定结果并不相同,并表现出双缩脲法的测定结果较凯氏定氮法小约10%～20%的规律。提出利用已标定蛋白质含量的稻米为标样,基于双缩脲反应原理,进行蛋白质测定的分析方法,结果表明,该法可获得较高的检测精度。

Comparison and analysis on determining methods towards protein in rice

The protein content of 10 rice samples were determined by Kjeldahl determination method and biuret reaction analytical method separately. Distinct difference was found by comparing from these two methods. The protein content determined by biuret reaction analytical method is 10%~20% lower than that determined by Kjeldahl determination method. An improved biuret reaction analytical method was presented for rice protein determination. With the method improved, the pre-marked rice powder was used as standard sample instead of pure protein, and higher precision was given than the conventional method.