Ohmic Heating Behaviour and Electrical Conductivity of Tomato Paste

Abstract

The ohmic heating rate of a food is highly influenced by its electrical conductivity (σ). In this study, tomato was ohmically heated by using five different voltage gradients (6–14 V/cm). Measurements were made from 26 to 96°C and showed a linear increase in σ values with increasing temperature. The voltage gradient was statistically significant on the heating time (P < 0.05). The ohmic heating system performance coefficients were in the range of 0.716-0.905. The pH varied from 4.20 to 4.51, over the voltage gradient range studied.