Comparison of Change of Quality for Six High-quality Indica Rice during After-ripening

After-ripening is one of the characteristics of grain, physiological and biochemical activities will exist in grain during this period. Its processing quality and edible quality will generally be improved after the completion of ripening. However, there are few studies on after-ripening of rice, one of the main grain crops in China. The physiological and biochemical indexes (germination rate, conductivity, roughness and fatty acid value), gelatinization characteristics and different enzyme activities (peroxidase, catalase, α-amylase) of six types of high-quality indica rice (Longliangyou 534, Huanghuazhan, Yingxiangsimiao, Yuenongsimiao, Xiadao 1 and Ayou 442) were measured regularly during after-ripening period to investigate the after-ripening duration of indica rice, the specific activity state during the after-ripening period and the quality change rules during after-ripening period of indica rice. The results showed that six kinds of high quality indica rice had different after-ripening duration, 6 varieties at ripening time of germination rate rose on the whole, the conductivity was fluctuating downward trend after rising first, out of the roughness increased volatility, the fatty acid value decreased firstly then increased, peroxidase varieties had differences in trends but volatility declined on the whole, the activity of catalase showed a fluctuating upward trend except Ayou 442, the activity of α-amylase showed a fluctuating downward trend except Huanghuazhan, and the peak viscosity showed a fluctuating upward trend at first and then a decreasing trend. The quality evaluation was carried out by principal component analysis, and the scores from high to low were Ayou 442, Longliangyou 534, Xiadao 1, Yuenongsimiao, Yingxiangsimiao, Huanghuazhan.