抗除草剂转基因稻米蛋白的消化稳定性和热稳定性分析

Digestive Stability and Heat Stability of Proteins of Genetically Modified Herbicide-Tolerant (GMHT) Rice

为抗除草剂转基因水稻食用安全性评价中的致敏性评估提供参考,对抗除草剂转基因稻米蛋白的消化稳定性和热穗定性进行分析.体外模拟胃肠液消化和热加工处理抗除草剂转基因水稻Bar68-1稻米蛋白、非转基因亲本对照D68稻米蛋白、阴性对照酪蛋白、阳性对照大豆胰蛋白酶抑制剂和牛血清蛋白,通过SDS-PAGE凝胶电泳观察它们在各时间点的降解情况.研究结果显示：消化稳定性试验中,转基因稻米蛋白和非转基因稻米蛋白在2 ～30 min内全部消化,可判断它们在模拟胃、肠液中可消化;热稳定性试验中,转基因稻米蛋白和非转基因稻米蛋白一样,在一定温度下（60、75、90、100℃）加热一定时间（15、30、60、120 min）后仍具有较好的热稳定性.结果表明,转基因抗除草剂水稻Ba68-1具有较好的热稳定性,在模拟胃液和模拟肠液中均可消化,不具备过敏原抗消化性的特征.

To provide information for allergenicity assessment in food safety assessment of genetically modified herbicide-tolerant （GMHT）rice,digestive stability and heat stability of proteins of GMHT rice are analyzed.Temporal dynamics for degradation of proteins of GMHT rice Bar68-1 and controls （protein of D68 as control of non-GM rice,casein as negative control,soybean trypsin inhibitor and bovine serum albumin as positive control） in vitro digestibility,and stability in simulated thermal processing environment,were detected by SDS-PAGE.Results showed that proteins of GMHT rice and non-GM rice were digested within 2-30 min,which means that they are digestible in simulated gastric fluid （SGF） and simulated intestinal fluid （SIF） ; Proteins of GMHT rice and non-GM rice were stable when heating at 60,75,90,and 100 ℃ for 15,30,60,and 120 min.Results indicated that proteins of GMHT rice and non-GM rice have good heat stability,and they are digestible in SGF and SIF.The digestive stability of GMHT rice has no characteristics of food allergens.