Ohmic Heating of Aloe vera Gel: Electrical Conductivity and Energy Efficiency

Abstract

Ohmic heating is defined as a process which alternating electric current is passed through food with the primary purpose of heating it due to the electrical resistance and can be specially applied as an alternative heating method. In this research, Aloe vera gel concentrates having 0.5-2% soluble solids were ohmically heated up to 60°C by using four different voltage gradients (30–60 V/cm). The dependence of electrical conductivity on temperature, voltage gradient, and concentration were obtained. Results indicated that there was a linear relationship between temperature and electrical conductivity. The range of the electrical conductivity was 0.45 to1.20 S/m, which was dependent on the concentration and voltage gradient, although the effect of concentration was very higher than voltage gradient. The ohmic heating System Performance Coefficients (SPCs) were calculated by using the energies given to the system and taken by the Aloe vera gel samples and were in the range of 0.67- 0.89 and the highest SPC (0.89) was observed at 0.5 % and 30 V/cm.

Keywords

• ohmic heating
• aloe vera gel
• concentration
• voltage gradient
• electrical conductivity
• energy efficiency