Rheological properties of SSIIIa-deficient mutants of rice grain and the starch towards tailor-made carbohydrate foods

为了揭示胚乳淀粉结构与淀粉糊流变特性之间的关系，对SSIIIa活性完全缺失的水稻淀粉合成酶IIIa缺陷型突变体及其亲本Nihonbaar进行了鉴定。SSIIIa与日本稻的米粒长度和宽度相近，但其米粒长度和宽度均大于日本稻。SSIIIa米粒的力-应变特征曲线表现为脆性。SSIIIa糊化和流变性的变化主要是由支链淀粉的结构引起的，SSIIIa被认为是一种有用的粮食原料。

Starch synthase IIIa (SSIIIa)-deficient rice mutant, that was completely absent in SSIIIa activity, and the parental Nihonbare were characterized to reveal the relationship between the structure of the endosperm starches and the rheological properties of its starch pastes. The length and width of raw rice grains of SSIIIa and Nihonbare were similar, but the cooked rice grains of SSIIIa became longer than Nihonbare. The characteristic force-strain curve on cooked rice grain of SSIIIa was showed brittleness. Changes in the pasting and rheological peoperties of SSIIIa were mainly caused by the structure of amylopectin and SSIIIa was thought to be useful food material as a domestic rice crop.