Association between rice protein components and eating quality traits of different rice varieties under different nitrogen levels

Abstract

Rice protein, varying in different nitrogen (N) fertilizer levels, is a crucial contributor to the eating and cooking qualities (ECQs) of rice. In this study, we investigated the relationship between protein components and ECQs of different rice varieties at different nitrogen fertilizer levels. Our results showed that prolamin and glutelin are the most abundant protein components in rice. Compared to the varieties, the effect of nitrogen fertilization on these two protein components was greater, with 59.3% and 45.9% of the variation in prolamin and glutelin soluble proteins being explained. Higher nitrogen application reduced the peak viscosity, trough viscosity, final viscosity, and breakdown, accompanied by lower adhesiveness and higher hardness in rice. Under nitrogen fertilization, prolamin and glutelin affected the ECQs of rice by affecting the adhesiveness and hardness of rice, respectively. At a nitrogen fertilizer level of 100 kg ha−1, the reduction in ECQs of rice was small and a balance between rice yield and ECQs could be achieved. Overall, our results suggested that appropriate N fertilization would reduce the deterioration of rice texture on account of elevated protein compositions.