Effect of pH on temperature increase and electrical conductivity
The temperature histories of orange juice samples exposed to ohmic and conventional heating are shown in Fig. 2. The heating rate of orange juice subjected to conventional heating was not affected by adjusting pH (Fig. 2A). On the other hand, the heating rate and electrical conductivity of orange juice subjected to ohmic uice samples. However, temperature and electrical conductivity increased more rapidly in orange juice of pH 4.0 and 4.5. Thirty-six s was needed for pH 4.5 samples to reach ca. 70 C, but 51 s and 63 s were needed for samples of pH 4.0 and 3.5, respectively.