An important consideration in ohmic heating is the amount and the chemical nature of the corrosion products migrating into the food during the application of electrical power. Table 2 shows a comparison of corrosion rates (ppb kJ−1) of the electrode materials with respect to the migrations of their major (surface) elements at different pH values. The analysis of variance suggests that both type of electrode material and pH, as well as their interactions, have significant effects on the corrosion rate. As can be seen from Table 2, the corrosion rates of titanium and platinized-titanium electrodes are not significantly different at any pH value, however these are significantly lower (P ⩽ 0.05) than the corrosion rates of stainless steel and graphite electrodes. On the other hand, the corrosion rates of stainless steel and graphite electrodes are not significantly different except at pH 3.5. Each of the electrode materials exhibits a higher corrosion rate at pH 3.5 than at the other pH values.