Physicochemical characterization and in vitro digestibility of resistant starch from corn starch sugar residue

This study sought to investigate the thermal stability and digestibility of corn starch sugar residue resistant starch (CSSR-RS) through comparative analysis of the physicochemical properties and structural characteristics among CSSR-RS, high-amylose corn starch (HS), and normal corn starch (NS). CSSR-RS contained 51.76 % resistant starch (RS), with 42.6 % remaining after high-temperature treatment, which was significantly higher than HS, demonstrating strong resistance to gelatinization. CSSR-RS is characterized by highly ordered aggregation of small molecules with a C-type crystalline structure, and irregular granular structures with wrinkled surfaces. Compared with NS and HS, the short-range and long-range order of CSSR-RS were significantly higher, indicating excellent thermal stability. <i>In vitro</i> simulated digestion revealed that the total hydrolysis rate of CSSR-RS was significantly lower than those of NS and HS, and the residual digesta of CSSR-RS also showed better resistance to digestion than HS. CSSR-RS exhibited significant development prospects in healthy food.