Physicochemical properties and health benefits of resistant starch, resistant dextrin, and polydextrose: Similarities and differences

This is a review on resistant starch (RS), resistant dextrin (RD), and polydextrose (PDX), focusing on their similarities and differences. RS refers to the starch (or a portion of) that cannot be digested in the small intestine, but can be partially fermented in the colon. The enzyme resistance of RS is mainly due to either its crystalline/granular structure or its interaction with other components. RD is produced by pyrodextrinization of starch, while PDX is produced by polycondensation of glucose and sorbitol. Both RD and PDX contain glycosidic linkages that are not digestible by the enzymes in the small intestine. RS is not soluble in water, whereas RD and PDX are soluble, mainly due to their molecular structures and other structural features. The major health benefits of RS, RD, and PDX are quite similar, including gut health, prebiotic effects, glycemic control, weight management, and prevention of cardiovascular disease. However, the efficacies can be different among them, for example, the degree and rate of gut fermentation. This review compares the definitions, functional properties, and health benefits of RS, RD, and PDX with the underlying mechanisms, which can be useful for their incorporation in food formulations to improve human health and wellness.