Research advances on the formation mechanism of resistant starch type III: A review.

Resistant starch (RS) plays a key role in providing metabolic and colonic health benefits. In particular, RS type III (RS) is of great interest because of its thermal stability and its preserved nutritional functionality. RS can be prepared by physical treatment, including high hydrostatic pressure, ultrasound, extrusion, autoclaving, microwave cooking, and heat-moisture treatment. The acid and enzymatic hydrolysis can also be applied to facilitate the generation of small molecules, which increases the inherent crystallinity of RS upon retrogradation. Depending on processing conditions, RS with diversified structural characteristics can be formed. These structures play a key role in determining the physiological behavior of RS. Therefore, a deep understanding of the structural rearrangement pattern during different processing treatment is of great importance for regulating the molecular structure of RS and thereby its corresponding physiological properties. This review thus focuses on the past and current status of research into the in-depth study of RS formation mechanism and the changes to RS structural characteristics under different processing conditions. The objective was to provide a theoretical guidance for the rational selection of preparation methods for RS and for designing RS structures with specific physiological functionalities for relevant industrial applications.