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 (RS3) is of great interest because of its thermal stability and its preserved nutritional functionality. RS3 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 RS3 upon retrogradation. Depending on processing conditions, RS3 with diversified structural characteristics can be formed. These structures play a key role in determining the physiological behavior of RS3. Therefore, a deep understanding of the structural rearrangement pattern during different processing treatment is of great importance for regulating the molecular structure of RS3 and thereby its corresponding physiological properties. This review thus focuses on the past and current status of research into the in-depth study of RS3 formation mechanism and the changes to RS3 structural characteristics under different processing conditions. The objective was to provide a theoretical guidance for the rational selection of preparation methods for RS3 and for designing RS3 structures with specific physiological functionalities for relevant industrial applications.