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.
出处
《食品科技》
CAS
北大核心
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
