Sorghum as a Healthy Global Food Security Crop: Opportunities and Challenges

Climate change is an enormous challenge facing humanity. To meet this challenge, a shift toward more climate resilient, but underdeveloped and underutilized, crops such as sorghum is of great interest. Sorghum performs relatively well under water scarcity and elevated temperature conditions compared with the major cereal crops wheat, rice, and maize (corn). From a nutritional perspective, a major advantage of sorghum as a healthy and nutritious crop is its higher proportion of slowly digestible and resistant starch components compared with other staple cereal crops. This property of sorghum reduces postprandial hyperglycemia in humans and could potentially be manipulated to reduce overall calorie intake from products made with sorghum. Sorghum also is uniquely rich in diverse bioactive polyphenols and other beneficial compounds that are associated with reduced risk of nutrition-linked chronic diseases, including type 2 diabetes, cardiovascular disease, and some types of cancer. Some of the bioactive compounds found in sorghum, such as high molecular weight tannins, also have technological benefits due to their ability to modify protein and starch functionality, which can be used to produce new bioactive ingredients or enhance food quality. The key challenges associated with use of sorghum as a food ingredient are its lower endosperm functionality and relatively low protein digestibility; both attributes are related to the tendency of the hydrophobic sorghum endosperm protein kafirin to cross-link during processing. Recent developments in the utilization of traditional genetics to alter the structure and functionality of the kafirin protein in sorghum show a lot of promise for unlocking the full food use potential of sorghum. These improved sorghum lines have demonstrated enhanced food use quality and protein digestibility. This review summarizes emerging opportunities and challenges associated with sorghum production and utilization as a healthy food ingredient.