Physicochemical properties of indica-japonica hybrid rice starch from Chinese varieties

Abstract

The knowledge of the properties of indica-japonica hybrid rice starch is limited but critical for different end uses. The starches separated from seven indica-japonica hybrid rice varieties were evaluated for structural, thermal, and pasting properties. The relationships between thermodynamic and structural properties were determined using Pearson correlation analysis. Starch contained large, medium, and small granules, and the volume distribution percentages of large and medium starch granules were significantly different among the seven varieties. Apparent amylose content varied significantly among the seven varieties. All the starches showed A-type crystallinity. Chunyou 84 had the highest short-range ordered degree, and Yongyou 2640 starch had the highest swelling power and water solubility. The thermal and pasting properties were significantly different among seven varieties. Chunyou 84 and Yongyou 2640 had the highest and the lowest gelatinization temperature and pasting viscosity, respectively. Starches with high proportion of large granules, high AAC or high degree of short-range ordered structure were harder to bind with water, however starches with high proportion of small and medium granules or high relative crystallinity were easier to bind with water. This study indicated that the structural and physicochemical properties of indica-japonica hybrid rice starches were significantly different. This study would provide some information for applications of indica-japonica hybrid rice starches in food and non-food industries.