Indonesia Conference Directory

Ohmic heating is considered as a novel technology for pasteurization. Ohmic heating rate is highly influenced by the electrical conductivity of the products. The heating rate and the stability of anthocyanin during ohmic heating need to be investigated in order to analyze the viability of ohmic heating for pasteurization of mulberry juice. Mulberry juice was heated using three different temperatures (80, 85 and 90 degree Celsius) during 90 minutes. Electrical conductivity of mulberry juice increased from 0.014 S/m at the initial of heating (32 degree Celsius) to 0.033 S/m at 90 degree Celsius and the average heating rate was 0.568 degree C/s. The heating rate and electrical conductivity increased linearly with the increased in temperature. Degradation kinetic of anthocyanin followed the first order kinetic models with coefficient of determination value over 0.9. The k value of anthocyanin degradation increases along with the increasing of temperature ranging from 0.008/min to 0.015/min. Anthocyanin shows relatively high temperature dependence with 135.83 kJ/mol energy activation value. Based on the heating rates obtained from this study, ohmic heating could be used as an alternative pasteurization method for mulberry juice.