5种豆类淀粉结构和理化性质分析

Structures and physicochemical properties of five kinds of bean starches

豆类中的碳水化合物以淀粉居多,且它的组成结构和理化性质直接影响到豆类淀粉产品的研究和应用。本研究以绿豆、鹰嘴豆、蚕豆、豌豆、芸豆5种豆类为试材提取淀粉,并对其结构和理化性质进行分析比较。结果表明,5种豆类淀粉颗粒形态相近、大小各异、多呈椭圆状,X射线衍射图谱分析表明,5种豆类淀粉均呈现C型结构、光谱吸收峰相似、仅在吸收峰强度上存在差异、直链淀粉含量均在25%以上,其溶解度和膨胀度都随温度上升而增大,芸豆淀粉糊的凝沉性高于其他4种淀粉糊,沉降体积在24 h后基本保持不变,冻融稳定性也都随着冻融次数的增加而减小,其中,绿豆淀粉的冻融稳定性最强,鹰嘴豆淀粉冻融稳定性最差,5种淀粉的酶解率随着水解时间的延长差异也变得较显著,尤其是豌豆淀粉受时间的影响最大。本研究为新疆豆类资源的开发利用提供理论依据。

Starch is the most abundant carbohydrate in beans,and its composition,structure and physicochemical properties directly affect the research and application of bean starch products.In this study,mung beans,chickpeas,broad beans,peas and kidney beans were used to extract starches,and their structures and physicochemical properties were analysed and compared.The results showed that the starch granules of five kinds of beans were similar and mostly elliptical in shape,and varied in size.XRD pattern analyses showed that all the five beans starches had C-type structure,the spectral absorption peaks of which were similar and only differed in their intensities.The amylose content of above 25%,and their solubility and swelling power increased with temperature rising.The retrogradation of kidney bean starch paste was higher than that of the other 4 starch pastes,and the retrogradation volume remained unchanged after 24 h.The freeze-thaw stability also decreased with the increase of freeze-thaw times,among which,the freeze-thaw stability of mung bean starch was the strongest and that of chickpea starch was the worst.The difference of enzymatic digestion rate of the five starches with the extension of hydrolysis time was significant,especially the pea starch.This study provides a theoretical basis for the development and utilization of bean resources in Xinjiang.