Improving rice cooking and eating quality: Panicle nitrogen fertilizer modifies amylopectin structure and amylopectin-protein interactions in post-ripening

Zongkui Chen; Xinrui Li; Yue Huang; Xiangyu Xu; Jinghan Cao; Jiayue Wang; Ziyou Yu; Wenqi Yuan; Zhixin Li; Jingsha Tang; Zhonglin Wang; Zhiyuan Yang; Yongjian Sun; Jun Ma; Xiafei Li

Carbohydrate Polymers, Vol. 378, Article number: 124902 (2026), April 2026 (IF=12.5)

Abstract

Starch granules properties (crystallinity and bond-energy traits) largely determine rice cooking and eating quality (CEQ), and these properties are predominantly influenced by amylopectin. This study investigated how panicle nitrogen management improves CEQ by examining changes in amylopectin structure, its complexes with glutelin/prolamin, and starch granule properties during the after-ripening period. Compared to other treatments, the panicle nitrogen fertilizer (N2; foliar spray at 45 kg N ha⁻¹) increased key amylopectin density (e.g., 2A4B1B2B3), promoting amylopectin–protein complexes formation. N2 increased crystallinity and microstrain while reducing interplanar spacing and surface functional group abundance. Overall, optimized amylopectin structure and its interactions with proteins under N2 improved starch granule properties, particularly after two months of after-ripening, thereby enhancing CEQ.

Keywords：Amylopectin structure; Starch granule properties; Functional groups; Starch; Protein