高粱单宁对小麦蛋白体外消化率及其结构的影响

Effects of Sorguhm Tannin on the Digestibility in vitro and Structures of Wheat Protein

目的:研究高粱单宁对小麦蛋白体外消化率及其性质的影响,为低热量小麦制品的开发利用提供依据。方法:采用丙酮从高粱壳中提取粗单宁,与小麦粉混合后制备面团;采用胃-胰蛋白酶两步消化法测定高粱单宁对小麦蛋白体外消化率的影响;应用红外光谱(FT-IR)、体积排阻色谱(SEC-HPLC)和扫描电镜(SEM)测定单宁和小麦蛋白混合后蛋白质结构的变化,探讨单宁与小麦蛋白之间相互作用的机理。结果:高粱单宁可有效降低小麦蛋白的体外消化率;蛋白质分子与单宁通过氢键发生缩合,形成较难溶解的络合物,扫描电镜观察进一步证实蛋白质与高粱单宁间的络合作用。结论:高粱单宁与小麦蛋白络合形成了难以被消化酶水解的络合物,从而降低了小麦蛋白的体外消化率。

Objective： To investigate effects of sorghum tannin on the digestibility in vitro and structures of wheat protein and provide evidence in developing low-cal wheat products. Methods： Tannin and wheat protein were extracted resectively from sorghum husks and wheat flour. Because of tannin, changes in digestibility in vitro and structure of wheat protein were determined by stomach-trypsin protease, FTIR, HPLC and SEM for discussing the mechanism of the interaction between tannins and wheat protein. Results： Sughum tannin could effectively reduce the wheat proteins digestibility in vitro. The complexation of wheat protein and sorghum tannin took place via hydrogen bonding. Possibly the complexes of wheat protein and sorghum tannin were difficult to be digested. SEM further evidenced the results. Conclusion： Sorghum tannin and wheat protein can form complexes via hydrogen bonding, and the former can reduce the digestibility in vitro of wheat protein.