Nitrogen-regulated amylose structure and complexation during post-ripening: A key to improving rice cooking and eating quality

Zongkui Chen, Xinrui Li, Wenqi Yuan, Yue Huang, Jiayue Wang, Xiangyu Xu, Xiaomeng Shen, Xuanjun Guo, Ziyou Yu, Zhiyuan Yang, Yongjian Sun , Jun Ma, Xiafei Li

Carbohydrate Polymers ,Volume 368, Issue Pt2, 15 November 2025（IF=12.2）

Abstract

After-ripening and panicle nitrogen fertilizer influence amylose structure and its complexation with proteins, which shape rice cooking and eating quality (CEQ), but their roles remain unclear. This study investigated how post-ripening duration and panicle nitrogen fertilizer (foliar application of 45 kg N ha-1, N2) modulate amylose structure and its interactions with proteins through field experiments and molecular dynamics. Post-ripening reduced glutenin, prolamin, amylopectin, and short/short-medium amylose-glutenin complexes while increasing short-medium chain amylose-prolamin complexes. These changes reduced viscosity traits, thereby lowering cooking quality. Among cultivar-nitrogen combinations, low amylose cultivars (D1) under N2 (D1N2) decreased glutenin and amylose but increased amylopectin, lowering hot and final viscosity. D1N2 also improved short and short-medium chain amylose structural traits, raising peak viscosity, while reduced amylose-glutenin/prolamin complexes further lowered hot and final viscosity. D1N2 increased starch granule hardness and extensibility, contributing to lower final viscosity. Overall, cooking quality declined after post-ripening, while D1N2 improved CEQ.