Electrical parameters of ohmically heated cow’s milk

Abstract

Science and industry are very interested in alternative pasteurization and sterilizing methods, like the direct electrical effect. An experimental batch ohmic heating unit was built and manufactured for this study. Our goal is to design and build batch Ohmic heating equipment that ensures adequate pasteurization of whole cow’s milk while also looking into the electrical phenomena that occur throughout the process. Ohmic and conventional heating technology were used to heat cow’s milk from 15 to 72°C. The temperature increased when ohmic heating was applied with varying voltage gradients (6.08, 9.56, and 19.13 V/cm), resulting in a substantial decrease (p≤ 0.05) in the heating time for milk pasteurization. The current that flows through the sample was higher at higher voltage gradients, which led to a quicker accumulation of heat. The change in electric current during ohmic heating of the milk is only dependent on the electrical conductivity when the voltage is constant. Ohmic heating induced a significant (p≤0.05) increase in system performance coefficient (SPC) values with increasing voltage gradients, resulting in heating rates (°C/minute).

Keywords

• conductivity, cow’s milk, gradient, Ohmic heating, heating rate.