Effect of high-pressure treatment on various starch-in-water suspensions

This study investigated the high-pressure-induced gelatinization of different starches, namely normal rice, waxy rice, normal corn, waxy corn, tapioca and potato starches. The high-pressure-treated starch solutions were characterized by pasting behaviour, degree of swelling and changes in birefringence. Potato starch was found to be less affected by pressure treatment than the other starches, as it retained birefringence after a pressure treatment of 600 MPa for 30 min. Waxy and tapioca starches showed complete gelatinization after the same treatment, whereas normal starches were only partially gelatinized. The pasting curves of the normal starches showed an increase in the initial viscosity after pressure treatment, whereas the initial viscosities of the waxy starches after the 600 MPa for 30 min treatment were already equal to their respective peak viscosities.