Sorghum starch: Composition, structure, functionality, and strategies for its improvement

Sorghum (Sorghum bicolor L. Moench) is increasingly recognized as a resilient and climate-adaptable crop that holds significant potential to enhance global food security sustainably. Compared to other common cereal grains, sorghum boasts a more diverse nutritional profile. The starch component accounts for more than 80% of total sorghum grain weight. Sorghum starch functionality and diverse industrial applications are determined by its physiochemical properties, including pasting, gelatinization, retrogradation, texture, and digestion kinetics. This review provides a comprehensive evaluation of the morphology, minor composition, crystalline structure, fine molecular structure, and structure-function relationships of sorghum starch. It further explores how these properties can be optimized through chemical, physical and enzymatic modifications to extend the applications of sorghum starch. Additionally, the review highlights the role of key enzymes in the biosynthesis of sorghum starch and discusses how biological modifications, enabled by advanced genetic and molecular breeding strategies, can modify starch quality. This review also provides a foundation for developing tailored sorghum varieties with enhanced starch properties that can expand applications of sorghum both in food and non-food industries, potentially contributing to global food security and sustainable agriculture.