Relationship between the Saccharides Extracted from Rice Grains during Cooking and the Sensory Taste of Cooked Rice

Abstract

The type of saccharide extracted while cooking Koshihikari, Nipponbare and Yukihikari rice, and its relationship with the taste of the cooked rice were examined.
A substantial amount of saccharide was extracted when cooking at temperatures in the ranges of 40-70°C and 80-98°C, the largest amount being at boiling point.
The ratio of amylose to amylopectin in the saccharide extracted at 70°C and 98°C and after the final steaming (murashi) was highest in the latter case for all three samples of cooked rice and higher than that in their raw state. Of the three varieties, the ratio for Koshihikari was the highest and showed a longer-chain fraction in the gel chromatography patterns.
Most of the saccharide extracted into the cooking water was absorbed by the rice grains during heating; some remained on the surface of the grains and affected the luster and adhesiveness of the cooked rice, which seems to have been related to the taste.