Modification in physicochemical, structural and digestive properties of pea starch during heat-moisture process assisted by pre- and post-treatment of ultrasound.

Ultrasound is increasingly used for physicochemical modification of food systems as a green technology. Effects of heat-moisture treatment (HMT) assisted by pre- and post-treatment of ultrasound on physicochemical, structural and digestive properties of pea starch was investigated. Pea starch maintained the original morphology and C-type of crystalline after ultrasound treatment (UT), but 4 h or more of HMT and HMT assisted by UT changed the crystalline from C-type to A-type. All treatments decreased the crystallinity, molecular weight, swelling power and solubility at 70-90 °C, and elevated the content of resistant starch. Moreover, HMT assisted by pretreatment of UT was found to increase the viscosity and high-temperature stability of starch paste compared with others by the orderly combined effect of UT-induced depolymerization and HMT-induced depolymerization and rearrangement of starch chains. These results may promote the appropriate use of ultrasound in food industries and the production of starch materials for potential applications.