Construction of electrostatic binding V-type starches using cationic starch and lauric acid: Insight into enhanced digestive resistance

This study developed a V-type starch with enhanced structural stability and digestive resistance through an electrostatic interaction between a cationic starch (CS) and lauric acid (LA). X-ray diffraction analysis revealed that the non-etherified sample complexed with LA (ETA-0%-LA) exhibits a typical B-type crystalline structure. When the ETA content was increased from 5% to 30%, the V-type crystallinity of the CS-LA complexes increased from 9.22% to 24.60%. The degree of substitution (DS) exhibited a clear dose-dependent response to the etherifying agent, with ETA-30% yielding the highest DS (0.075%). Dynamic viscoelastic analysis further indicates that the electrostatic interaction between CS and LA substantially strengthened the gel network structure of CS-LA complexes. In vitro digestion tests confirmed that the moderate cationization markedly increasing resistant starch content and decreasing rapidly digestible starch content. These findings indicate that electrostatic interaction plays a key role in modulating the structural stability and digestive resistance of V-type starch.