蛋白酶水解大豆分离蛋白的分子水平表征  

Characterization of enzymatic hydrolysates of soybean protein isolate on molecular level

作　　者：庞美蓉[1] 丁秀臻[1] 孔祥珍[1] 华欲飞[1] 

机构地区：[1]江南大学食品学院,食品科学与技术国家重点实验室,江苏无锡214122

出　　处：《中国油脂》2013年第5期20-23,共4页China Oils and Fats

基　　金：国家自然科学基金主任基金(21146002);江苏省自然科学基金项目(BK2011151);江南大学食品科学与技术国家重点实验室开放课题资助课题(SKLF-ZZB-201202)

摘　　要：采用两种蛋白酶(胃蛋白酶和碱性蛋白酶)对大豆分离蛋白进行水解,水解结束调节pH至4.8,离心分离得到酸可溶蛋白和酸不可溶蛋白。考察不同的蛋白酶、水解时间、温度以及未添加蛋白酶的情况下,酸不可溶蛋白所占比例,并采用SE-HPLC和SDS-PAGE对这些酶解物进行了分子水平的表征。结果发现:胃蛋白酶选择性地水解大豆球蛋白(11S),在pH 2.0、37℃条件下水解6 h,酸不可溶蛋白所占比例为51.14%,其相对分子质量大于10 kDa的部分占到50%以上。水解温度对碱性蛋白酶水解大豆分离蛋白的影响较大,在pH 8.0、60℃条件下水解1 h获得的大豆分离蛋白碱性蛋白酶酶解物的相对分子质量主要分布在20 kDa以下。不同蛋白酶水解大豆分离蛋白,其水解进程存在显著差异,即使是采用同一种蛋白酶进行水解,不同的水解条件下得到的酶解物分子结构也大不相同。Soybean protein isolate was hydrolyzed by pepsin and alcalase respectively, and then acid - soluble protein and acid - insoluble protein were prepared by adjusting pH to 4. 8 and centrifugation. The contents of acid -insoluble proteins prepared under different hydrolysis conditions were measured, and the enzymatic hydrolysates were characterized on molecular level by SE - HPLC and SDS - PAGE. The results showed that soybean glycinin 11S was selectively hydrolyzed by pepsin and the content of acid - insoluble protein obtained was 51.14% when the soybean protein was hydrolyzed at pH 2. 0,37℃ for 6 h, in which the content of the fraction with the relative molecular weight above 10 kDa was over 50%. Hydrolysis temperature had remarkable influence on soybean protein isolate hydrolyzed by alcalase. The relative molecular weight of enzymatic hydrolysates with alcalase was mainly below 20 kDa under the hydrolysis conditions of 60℃, pH 8.0 and 1 h. Hydrolysis processes with different proteases varied sig- nificantly. Even the enzymatic hydrolysates obtained with the same protease under different hydrolysis conditions had significantly different molecular structures.

关 键 词：蛋白酶 大豆分离蛋白 水解 胃蛋白酶 碱性蛋白酶 相对分子质量 

分 类 号：TS201.25[轻工技术与工程—食品科学]