Development of a numerical model for measuring the electrical conductivity (EC) of a cake batter

Abstract

International audienceThe electrical conductivity (EC) of materials represents their ability to conduct electrical current and determines the power dissipated within the material. This parameter can be temperature and electric field dependent. When EC is measured in the electric fields used for ohmic heating, the increase in temperature results in heating nonuniformity in the measuring cell. As a result, the relationship between EC and temperature cannot be accurately determined. In addition, for cake batter, starch gelatinization occurs during the measurement, leading to more complex EC curves. To address these issues, this study proposes a numerical method for determining EC that accounts for temperature non-uniformity. This model is coupled with a starch gelatinization model. The principle is based on the estimation of the EC using the method of least squares between the experimental temperature and the numerical one. The estimation of the EC of the cake batter consists of two steps: first, the device was characterized with xanthan and potassium chloride solutions of known electrical conductivities. A conversion efficiency of 0.77 was found. This efficiency was used to estimate the EC of the cake batter as a function of temperature and for different electric fields. Results showed that EC became independent of the electric field from 34.57 V/cm