Influence of Environmental Factors on the Starch Quality of Sorghum: A Multifaceted Analysis of Structural, Nutritional, and Functional Profiles

Understanding how environmental factors modulate starch structure and functionality in sorghum is critical for optimizing its application in the food processing and fermentation industries. In this study, two sorghum cultivars with distinct starch types-Liaonian 3 (LN3, waxy) and Liaoza 82 (LZ82, non-waxy)-were cultivated across four major ecological regions in China to systematically investigate the combined effects of temperature and precipitation on grain composition, starch molecular structure, and processing properties. Comprehensive analyses, including scanning electron microscopy, molecular weight profiling, chain-length distribution, crystallinity, molecular order, and thermal/pasting behaviors, demonstrated that precipitation is the predominant environmental factor driving starch biosynthesis and structural assembly. High precipitation levels promoted amylopectin accumulation, shorter chain formation, increased branching degree, and higher crystallinity and molecular order, ultimately enhancing starch thermal stability and paste consistency. Genotypic differences further modulated starch structural patterns and environmental responsiveness, with LN3 consistently exhibiting higher amylopectin content, crystallinity, double-helix proportion, and gelatinization enthalpy compared to LZ82. Correlation analyses revealed genotype-dependent regulatory relationships linking environmental cues to starch structure and processing functionality. These findings provide a comprehensive framework elucidating the environmental regulation of starch structure-function relationships in sorghum, offering theoretical insights for climate-resilient breeding and functional starch development.