Effect of Dual Modification Order with Ultrasound and Hydrothermal Treatments on Starch Digestibility

In the present study, the effects of the order of dual modification on the in vitro digestibility and structural properties of maize starch are investigated. Dual modification of maize starch is carried out by combining ultrasonication (S) (1, 2, 4, 8, and 16min) and heat-moisture treatment (HMT) in different sequences (S-HMT and HMT-S). The dual-modification treatment caused the rearrangement of the starch structure, increasing the resistant starch (RS) content of the uncooked samples. Moreover, HMT-S produced thermo-stable SDS and RS. Differential scanning calorimetry indicated short-range changes, as is reflected by modifications of the gelatinization parameters of the treated starches. The results suggest that the structural changes of maize starch by dual modification affected the digestibility regardless of the treatment sequence.