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.