发芽糙米淀粉理化特性研究

采用富集γ-氨基丁酸(GABA)的优选糙米发芽工艺条件,通过碱酶两步法提取糙米淀粉,研究发芽对糙米淀粉结构和理化特性的影响。结果表明:糙米发芽后,淀粉膨胀度增大,且随温度升高而提高;透明度升高了57.14%;峰值黏度基本不变;冻融稳定性提高,凝沉特性得到改善;淀粉凝胶的凝胶粘性有所提高,硬度和胶凝性有所降低;碘兰值减小,说明糙米发芽后其直链淀粉含量降低或聚合度减小;电镜分析结果显示,发芽后糙米淀粉颗粒变得圆滑,棱角较发芽前不明显。综上得出,发芽对糙米淀粉的理化特性具有一定的改善作用。

The Study on Physicochemical Properties of Germinated Brown Rice Starch

With the optimal germination conditions on brown rice of GABA enrichment,two-step by alkali and enzyme was used to extract the starch from the brown rice,and the changes of starch structure of brown rice and physicochemical properties after germination were studied in the paper.The results showed that:The swelling power was increased after germination,and increased with the temperature rising;the transparency was increased by 57.14%;the peak viscosity was inhibited obviously and the freeze-thawing stability was enhanced strongly after germination;the adhesiveness of starch gelatin was increased after germination,hardness and gumminess were both decreased;iodine blue value was decreased;it indicated that the amylose content or the degree of polymerization decreased after germination;electron microscopy analysis showed that germinated brown rice starch granules were round,and the angular were not obvious after germination.It showed that germination could improve the physicochemical properties of brown rice starch.