The role of indica starch in the mechanism of formation of fresh rice noodles

Abstract

Starch is the largest component in frequently consumed fresh rice noodles (FRN). The effects of morphology, relative crystallinity, molecular weight distribution and physicochemical (rheological, water hydration and gel texture) properties of starch from five rice cultivars with different amylose contents on the formation of FRN were investigated. FRN made from NR rice cultivar, used for commercial rice noodles making, showed excellent FRN texture. NR starch exhibited larger G′ and smaller tan δ values. The morphology of FRN from GM03 cultivar was closest to NR, but had higher hardness and lower springiness, resilience and cohesiveness. Its starch granules morphology was relatively small and round. The extracted starch from Zhongzao 35, Zao 87 and BX02 rice cultivars, with higher swelling power or lower proportions of amylose (FrI) and higher proportions of amylopectin (FrII), could not produce a dense and consistent FRN structure. It was observed that relative crystallinity of the starch samples had no influence on the formation of FRN. Nevertheless, the gel texture of starch played a role in the formation of FRN. The formation of FRN is the common effect of structure and physicochemical properties of rice starch. The finding of this research would be useful in understanding the role of starch in producing FRN of high quality.