玉米淀粉磷酸双酯的理化特性研究

Characteristic Study of Phosphodiester in Corn Starch

摘要:

以玉米淀粉为参照，采用红外光谱、差示扫描量热分析、快速粘度分析等现代仪器分析方法对玉米淀粉磷酸双酯的结构特征、热力学特性、黏度特性等物化性质进行了测定和研究，并采用体外消化方法，模拟人体肠道体系，研究了玉米淀粉磷酸双酯的消化特性，根据淀粉水解百分率推算其血糖指数的变化。结果表明，玉米淀粉经三偏磷酸钠酯化交联后，其红外光谱在1028 cm-1处出现新的吸收峰，说明分子中引入了磷酸根基团；样品的糊化温度和热焓值都有所升高，随着结合磷含量增加，淀粉糊黏度降低，稳定性增强；随着酯化度的增加玉米淀粉磷酸双酯抗消化淀粉含量显著上升，消化能力有较大水平的降低，高酯化度玉米淀粉磷酸双酯预测血糖指数为67.11，为中等血糖指数食品，可以添加在食品中为糖尿病患者食用。

Abstract:

The granule structure, thermal property and viscosity property of corn starch phosphodiester were investigated by Fourier transform infrared (FT-IR), differential scanning calorimeter (DSC), and rapid viscosity analyzer (RAV). The in vitro digestibility of corn starch phosphodiester was also studied by simulating human intestinal system with the comparison of corn starch. Meanwhile, Glycemic index (GI) was conjectured according to the percentage of starch hydrolysis. After cross-linked with sodium trimetaphosphate, new absorption peaks were appeared at 1028 cm-1, indicating phosphate groups were incorporated into the molecular structure. In addition, the gelatinization temperature and gelatinization enthalpy of corn starch phosphodiester were increased. With the increase of phosphorus content, the viscosity of starch paste was decreased, but stability was enhanced. The contents of resistant starch of corn starch phosphodiester increased significantly, whereas the digestibility significantly decreased. The predicated GI of corn starch phosphodiester was 66.31, which belonged to middle GI foods, and could be appropriate for the diabetes food.