Abstract

Effect of ageing process on rice physicochemical and digestion properties

Author(s): Zhongkai Zhou, Paiyun Zheng, Xiaoshan Chen, Yan Zhang

Three rice cultivarswith different amylose contentswere used for studying the effect of storage on rice structure and digestion behaviours. The amount of cellwall remnants of rice stored at 37ï‚°C increased over the storage. The pasting studies indicate that rice samples stored at 37ï‚°C demonstrated a consistent increase in time to peak viscosity (TTPV) of the RVA curve during the storage, suggesting a quick ageing progress. Ageing led to the decrease in the leaching of starch molecules during cooking, indicating the reduction of hydration and swelling of starch granules in aged rice grain. Digestion study shows that ageing process significantly reduced rice digestion kinetics both in rate and extent. Thus, it is assumed that ageing led to rice grain becomingmore organized in structurewhich reduced starch granule disruption and molecules leaching, and subsequently affected the rice digestion properties. This study suggests that the changes in digestion behaviours of rice are highly associated with the changes in rice physicochemical properties occurred during storage and ageing is one of useful methods for manipulating rice digestion properties