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
juice 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