小麦胚乳A、B型淀粉粒理化特性研究

【目的】研究小麦胚乳A、B型淀粉粒对其理化特性的影响。【方法】利用扫描电镜对4个小麦品种籽粒发育不同时期自然断面和分离提纯的A、B型淀粉粒进行观察;用直链、支链淀粉试剂盒对籽粒不同发育时期胚乳中A、B型淀粉粒的直链、支链淀粉含量进行测定;成熟籽粒A、B型淀粉粒膨胀势依据McCormick的方法进行了测定。【结果】小麦胚乳淀粉粒形态出现规则形状和反常态,胚乳淀粉粒中直链淀粉形成早于支链淀粉,但最终积累量支链淀粉大于直链淀粉。供试的4个品种中,B型淀粉粒膨胀势均大于各自A型淀粉粒的膨胀势。【结论】小麦胚乳A型和B型淀粉粒从形态上分为常规型和反常型。成熟小麦胚乳A、B型淀粉粒中,支链淀粉的含量大于直链淀粉,且与总淀粉含量呈正相关趋势。B型淀粉粒的膨胀势大于A型淀粉粒。

Physico-Chemical Characteristics of A,B Type Starch Granule in Wheat Endosperm

【Objective】 Effects of A, B type starch grannule in wheat endosperm to its physico-chemical characteristics were studied in an experiment. 【Method】 The natural ruptured side of kernel of different deveoping periods and the separated and purified A, B type starch granules of mature wheat endosperm in 4 wheat cultivars were observed by scanning electron micrographs (SEMs). The contents of amylose and amylopectin in A, B type starch granules of wheat endosperm of different development periods were determined by amylase/amylopectin assay procedure. The swellings of A, B type starch granules in mature wheat endosperm were measured according to McCormick. 【Result】 SEMs results showed that the shape of starch granules in wheat endosperm could be divided into normal form and abnormal form. The formation of amylose in starch granule of wheat endosperm was earlier than that of amylopectin, while the final content of amylopectin was much higher than that of amylose. The swelling power of B-type starch granule was higher than that of A-type starch granule in 4 cultivars. 【Conclusion】 The shape of A, B type starch granules in wheat endosperm could be classified into normal form and abnormal form. The contents of amylopectin in A, B type starch granules of matured wheat endosperm were higher than that of amylose and had a positive correlation trend to total starch content. The swelling of B-type starch granule was higher than that of A-type starch granule.