Relationship between protein structure and eating quality of rice under different nitrogen application rate

Abstract

Abstract Background and Objectives The mechanisms underlying the effects of proteins on the eating quality of rice remain elusive. In this study, the effect of content and secondary structure of four rice proteins (glutelin, globulin, albumin, and prolamin) on eating quality was investigated with rice subjected to nitrogen treatment at 160, 210, 260, 315, and 420 kg N/ha in the field. Findings The results showed that applying nitrogen fertilizer remarkably increased glutelin and globulin contents ( p < .05), especially the methionine content of globulin, leading to increased hardness of cooked rice. Moreover, excessive nitrogen significantly reduced the ratio of the prolamin α‐helix structure ( p < .05), which had a significant correlation with hardness and pasting temperature ( p < .05), at correlation coefficients of −0.859 and 0.828, respectively. Conclusion Besides protein content, the changes in amino acid content and protein secondary structure were also closely related to the eating quality of rice. Significance and Novelty Those results provided a new idea for breeding, cultivating, and processing technology regulation aimed at improving the eating quality of rice.