Efficiency of high hydrostatic pressure in preparing amorphous granular starches

To investigate the possibility of amorphous granular starch (AGS) preparation from corn, tapioca, potato, sweet potato, waxy rice, and normal rice starches with non-thermal HHP treatment, all starches were treated at 20°C for 30-‰min at 550-‰MPa. Ethanol (EtOH) and distilled water) were used to wash the high hydrostatic pressure (HHP)-treated starches, and the microscopic and macroscopic properties of the resultant starches were investigated. EtOH washing after HHP treatment allowed HHP-treated starch to retain the granular shape similar to that of its native form. HHP-treated corn, tapioca, and normal rice starches completely gelatinized but maintained granular structures, successfully achieving AGSs. Although HHP-treated potato and sweet potato starches exhibited their granular structures, gelatinization became incomplete. Waxy rice starch no longer exhibited its granular structure after HHP treatment. HHP-treated starches (forming AGSs) from corn, tapioca, and normal rice exhibited different microscopic and macroscopic properties compared to their respective native ones and non-AGSs.