Starch multiscale structure and physicochemical property alterations in high-quality indica rice quality and cooked rice texture under different nitrogen panicle fertilizer applications.

The starch multiscale structure, physiochemical properties, grain quality and cooked rice texture of high-quality early and late indica were analyzed under nitrogen panicle fertilizer (low panicle fertilizer, LPF; middle panicle fertilizer, MPF; high panicle fertilizer, HPF) treatments and their internal relations were investigated. Compared to the MPF treatment, the starch granules in HPF and LPF had more surface-proteins and irregular voids for high-quality early and late indica rice cultivars, respectively. Nitrogen panicle fertilization application increased amylopectin medium and long chains as well as protein content, resulting in higher relative crystallinity and gelatinization temperatures. Moderate changes in starch multistructures and physicochemical properties such as branching degree, amylopectin medium chain, and pasting viscosities derived from MPF treatment significantly improved processing, appearance qualities and cooked rice texture. Additionally, the decrease in starch branching, gelatinization temperatures, and granule uniformity along with an increase in large granules, breakdown, and △H gel under MPF treatment were the main reasons for improving rice textural properties. • Middle nitrogen panicle fertilization (MPF) improved cooked rice texture. • MPF treatment improved processing quality by increasing amylopectin medium and long chains. • MPF improved appearance quality by increasing starch pasting properties. • The improvement in cooked rice texture was due to increasing ∆H gel under MPF. • Protein attached to starch granules surface under HPF treatment decreased ∆H gel. [ABSTRACT FROM AUTHOR]