乳清蛋白水解物水解度3种测定方法的比较  

Various methods available for the determination of hydrolyzed degree of whey protein

作　　者：李晓东[1] 牛治霞[1] 张柏林[1] 

机构地区：[1]北京林业大学生物科学与技术学院食品科学系,北京100083

出　　处：《中国乳品工业》2006年第10期59-62,共4页China Dairy Industry

基　　金：北京林业大学研究生自选课题基金资助(05jj042)

摘　　要：选用胰蛋白酶水解乳清浓缩蛋白,对不同时间乳清蛋白水解液的水解度测定表明,pH-stat法与茚三酮比色法获得的乳清蛋白水解液的水解度基本一致,而甲醛滴定法测定的结果偏低。按本文的实验条件,pH-stat法与茚三酮比色法获得的结果最接近实际值。鉴于pH-stat法对酶的类型和水解条件有一定的要求,茚三酮比色法则无此方面限制,因此认为茚三酮比色法是目前三种方法中最适合测定乳清蛋白水解液水解度的方法。Trypsin was used to hydrolyze whey protein concentrate, and then its degree of hydrolysis （DH） from whey hydrolysates within 8h-incubation period was determined based on three assay methods, i.e. pH-stat, formaldehyde titration and ninhydrin coclorimetry. It was seen that the DH-value obtained with formaldehyde titration was considerably lower than that obtained with the other two methods. The accuracy of DH values obtained with pH-stat method depended greatly on temperature, pH and enzyme type used in the present study, although this determining-method produced good result. Our experiments showed that ninhydrin coclorimetry might be recommended for the appropriate assay of hydrolyzed degree of whey protein since the DH-values of whey hydrolysates obtained with this method had less relation to enzyme preparations used during the whole hydrolysis reaction.

关 键 词：乳清浓缩蛋白 水解度 胰蛋白酶 

分 类 号：TS252.7[轻工技术与工程—农产品加工及贮藏工程]