Characterization of Amylopectin Fine Structure and its Role on Pasting Properties of Starches in Rice (Oryza sativa L.)

抄録

The characteristics of amylopectin fine structure in rice starches are still elusive and the effect of amylopectin fine structure on starch physicochemical properties remains to be determined. In this paper, the fine structure of amylopectin especially the ratio of A-chains to B-chains was investigated using the improved enzymatic method. The influences of amylopectin fine structure on pasting properties of 91 rice accessions were also analyzed. The statistics results showed that the fine structure of rice starches highly varied with cultivars and these accessions were representative in terms of rice quality. Further correlation studies suggested that the ratio of A-chains to B-chains was negatively correlated with setback viscosity and pasting temperature, while average chain length and average external chain length was positively correlated with them, which indicated that the length of external chain and proportion of long and short chain of amylopectin played an important role in determining the rice cooking quality and functionality.