Effects of water-deficit and high-nitrogen treatments on wheat resistant starch crystalline structure and physicochemical properties

Abstract

This work investigated the effects of water-deficit and high-nitrogen (N) treatments on wheat resistant starch (RS) formation, molecular structure, and physicochemical properties. The results of consecutive 2-year field experiments revealed that water deficit significantly reduced starch granule number and diameter, amylose, RS content, RS particle size distribution, and physicochemical properties, including peak and trough viscosities, oil absorption capacity, and freeze-thaw stability. Water deficit also altered the long- and short-range structures of RS. In contrast, high-N fertilizer application significantly improved the RS content, long- and short-range structures, and physicochemical properties. Pearson correlation analysis revealed that RS content was positively correlated with total starch, amylose, rapidly digesting starch, 90th percentile of RS particle size, relative crystallinity, infrared 1047/1022 cm−1 ratio, peak and breakdown viscosities, oil absorption capacity, and freeze-thaw stability, and was negatively correlated with slowly digestible starch content, 1022/995 cm−1 ratio, and final viscosity.