甘薯可溶性蛋白sporamin胰蛋白酶抑制剂活性的两种测定方法比较及温度对其活性的影响  

Comparison of two determination methods of trypsin inhibitor activity and effect of heat treatment on trypsin inhibitor activity of Sporamin from Sweetpotato

作　　者：邓乐[1] 熊志冬[1] 李鹏高[2] 木泰华[1] 

机构地区：[1]中国农业科学院农产品加工研究所食品化学与营养研究室,北京100193 [2]首都医科大学公共卫生与家庭医学学院营养教研室,北京100069

出　　处：《食品科技》2009年第8期252-256,共5页Food Science and Technology

基　　金：国家高技术研究发展计划(863计划);"甘薯蛋白深加工技术的研究与开发"(2006AA10Z332);现代农业产业技术体系建设专项资金

摘　　要：从徐薯55—2中提取纯化了甘薯可溶性蛋白sporamin。采用Smith推荐的方法测定了sporamin的胰蛋白酶抑制剂活性，拟合分析结果表明：在对胰蛋白酶抑制率为20％-70％的范围内，胰蛋白酶抑制率与sporamin的浓度呈线性关系，回归系数R^2为0．983。并测得sporamin的胰蛋白酶抑制剂活性为（735．32±12．11）TIU／mg，此法能准确的对胰蛋白酶抑制剂活性进行定量分析，再现性较好。而Kunitz的方法能准确测定sporamin对胰蛋白酶的抑制率，适用于定性分析，且方法比较稳定。将未处理的sporamin和分别在70、90、100、127℃加热处理30min的sporamin用Smith推荐的方法测定其胰蛋白酶抑制剂活性，结果分别为718．00±19．80、650．00±14．14、564．00±33．94、496．00±45．25TIU／mg和（34．00±2．83）TIU／mg。Sporamin在100℃下高温处理30min后仍有较高的活性，而在127℃高压锅处理后其活性几乎完全丧失。Sporamin, a soluble protein of sweet potato, was extracted and purified from Xushu-55-2. The trypsin inhibitor activity of sporamin was determined using the method of Smith, and show a fairly linear relationship with the concentration of sporamin between an region of the inhibitor rate from 20% to 70%. The R2 was 0.983 and the trypsin inbitor activity was（735.32±12.11） TIU/mg. This result suggested that this method could be applied to the qualitative and quantitative analysis of trypsin inhibitor activity. The trypsin inhibitor activity was also determined using the method of Kuntiz, the result suggested that this method could be applied to the qualitative analysis of trypsin inhibitor activity. Both of these methods were reproducible. The inhibition rate of sporamin untreated and treated at 70, 90, 100 ℃ and 127 ℃ for 30 min were determined by Smith＇s method, the trypsin inhibitor activity were 718.00±19.80, 650.00±14.14, 564.00±33.94, 496.00±45.25, and （34.00±2.83） TIU/mg respectively. Sporamin remained a higher trypsin inhibitor activity even if heating at 100 ℃ for 30 min, but it was almost lost after heating at 127℃ by an autoclave.

关 键 词：SPORAMIN TI 胰蛋白酶抑制剂活性 热处理 

分 类 号：TS207.3[轻工技术与工程—食品科学]