薏米难糊化的机理研究

以糯米为参照,测定薏米的营养成分、淀粉颗粒大小、淀粉的热特性、结晶度和支链淀粉分子链长分布等指标,研究薏米难糊化的机理。研究结果表明:薏米的淀粉含量和水分含量均极显著低于糯米(p<0.01),蛋白质含量极显著高于糯米(p<0.01);薏米淀粉颗粒的粒径小于糯米淀粉;薏米淀粉的初始糊化温度和热焓值分别是糯米淀粉的1.08倍和2.04倍;薏米淀粉的结晶度是糯米淀粉的1.14倍;薏米支链淀粉FRI和FRIII分别比糯米降低了67.48%和11.87%。薏米难糊化的原因是由低淀粉含量和水分含量、高蛋白质含量、高淀粉热焓值和初始糊化温度、高淀粉结晶度、低支链淀粉FRIII含量等原因综合引起的,薏米淀粉的颗粒大小不是影响其难以糊化的因素。

Study on Mechanism of Gelatinization of Adlay

Gelatinization mechanism of adlay was studied comparing with glutinous rice.Parameters of nutrition content,the size of starch granule,thermal characteristic,crystallinity,and distribution of amylopectin chain length were determined.The results showed that compared with that of glutinous rice,content of starch and water of adlay was very significantly lower,but content of protein was very significantly higher(p<0.01);The size of starch granule of adlay was lower;The initial gelatinization temperature and starch enthalpy of adlay starch was 1.08 times and 2.04 times of that of glutinous rice starch,respectively;Content of FRI and FRIII of amylopectin was 67.48% and 11.87% lower than that of glutinous rice,respectively.Adlay is difficult to gelatinize thoroughly because of lower starch content and water content,higher protein content,higher starch enthalpy value and initial gelatinization temperature,higher starch crystallinity,lower content of FRIII of amylopectin.But the size of starch granule was not the main reason.