Sorghum Starch and Protein Digestibility: Mechanisms, Modifications, and Health Implications

This review examines sorghum digestibility from molecular structure to clinical implications, focusing on compositional factors, processing methods, and health outcomes. We evaluate how sorghum's unique protein-starch interactions influence digestibility and explore emerging technologies that can modulate these properties for targeted nutritional benefits. Cooked sorghum generally has lower digestibility than raw sorghum and other cereals due to heat-induced protein-starch cross-linking and the formation of disulfide bonds by sorghum proteins (kafirins), which restrict enzymatic access. Enzyme inhibitors in sorghum further reduce starch hydrolysis. This reduced digestibility may negatively impact malnourished individuals and those relying on sorghum as a dietary staple. However, it can be advantageous to individuals with diabetes by lowering postprandial blood glucose levels. Sorghum consumption may also beneficially influence the gut microbiome. Certain processing methods have been shown to significantly enhance digestibility while preserving beneficial bioactive compounds. Improving digestibility through these strategies may enhance sorghum's value for vulnerable populations while maintaining its metabolic advantages. Balancing increased nutrient bioavailability with preservation of beneficial functional properties is critical for optimizing sorghum as a health-promoting grain across diverse populations.