Effects of leached amylose and amylopectin in rice cooking liquidon texture and structure of cooked rice

Abstract

Effects of leached amylose (AM) and amylopectin (AP) on textural and morphological properties of cooked rice were investigated separately by replacing cooking liquid with AM and AP separated from pouring cooking liquid. The pouring of cooking water reduced the hardness (from 28.45 to 19.42N) and stickiness (from 1.74 to 1.19N·s) significantly. However, the addition of AM and AP enhanced the hardness (27.63N) and stickiness (1.71N·s).Scanning electron microscopy show that the leached short-chain AM entered the surface hollows in the cooked rice after water evaporation. Meanwhile, the Long-chain AM cross-linked to formed a three-dimensional network structures, which covered on the filled hollows. This distribution led to a harder texture of cooked rice. The leached AP absorbed water and swelledto form masses. Atthe gelatinization temperature, the APmassesagglomeratedtoformafilmlayer,whichcoveredtheunevenstructure, the thicker and smoother film contributed to the sticky texture.