甲醛值滴定法快速测定牛奶中蛋白质含量  

Determination of Protein Content in Milk by Formaldehyde Value Titration

作　　者：田志梅[1] 

机构地区：[1]河北省衡水市疾病预防控制中心,河北衡水053000

出　　处：《中国食品卫生杂志》2008年第3期244-245,共2页Chinese Journal of Food Hygiene

摘　　要：目的建立牛奶中蛋白质的快速检验方法-甲醛值滴定法。方法利用氨基酸的两性特性,加入甲醛溶液并用标准碱溶液滴定,通过测定牛奶中蛋白质的游离氨基酸含量,计算求得牛奶中蛋白质含量。结果牛奶中蛋白质含量与游离氨基酸含量呈良好的正相关,RSD%2.63～3.40,本法与国标法两种方法测定结果的绝对差值与其算术平均值之比小于5%,测定时间由约3h缩短为3～5min。结论本方法有效地解决了非蛋白质类的含氮物质对牛奶中蛋白质测定结果的干扰问题,适用于牛奶与奶粉中蛋白质的快速定量检验。Objective To determine protein content in milk by formaldehyde value titration, Method Using amphoteric property of amino acids, the formaldehyde solution was added into milk sample, and then the sample was titrated by standard alkali, The protein content in milk was calculated by determining free amino acids of it. Results There was a good correlation between protein content in milk and free amino acids. The RSD was 2,63 % - 3.40 %, Compared with the national standard method, ＂the ratios of absolute difference to its arithmetic average Of two methods were all below 5 % , The determining time was 3 - 5 min, and less than 3 b of national standard method, Conclusion The method could effectively resolve the interference problems of nitrogen substances which belong to non-protein kinds, and apply to rapid quantitative test of protein in milk and milk powder,

关 键 词：乳 蛋白质类 甲醛 滴定分析法 

分 类 号：R151[医药卫生—营养与食品卫生学]