Effect of microwave heating on optical and thermal properties of rice starch

摘要

This study used the oil bath to imitate the high heating rate of the microwave heating (MV) and evaluated the effects of conventional and MV on optical and thermal properties of rice starch at the same heating rate. The results indicated that the time-temperature profiles for microwave and rapid conventional heating fitted well, with a correlation coefficient of 0.9989. During both conventional and MV starch granule did not swell until 60°C, and granule swelling and loss of granule birefringence occurred simultaneously. DSC revealed a 50% decrease in enthalpy when temperature rose from 60 to 65°C, and a further decrease in enthalpy until 70°C. Therefore, microwave irradiation had no effect on the optical and thermal properties of starch during gelatinization.