Inactivation of Byssochlamys fulva during ohmic heating of tomato juice

Abstract

Ohmic heating is an emerging direct thermal technology, which uses electricity to heat food products volumetrically. Ohmic heating provides thermal and non-thermal effects like electropermeabilization to inactivate microorganisms. In this study, ohmic heating was used to inactivate Byssochlamys fulva in tomato juice. The main and interaction effects of initial pH (3.5 and 4.5) and voltage gradient (15 and 20 V/cm) were investigated on mold inactivation during ohmic heating at 88, 93, and 98 °C for 20, 10 and 5 min, respectively. The pH, acidity, total soluble solids, and Dvalue were compared. The results showed that pH and voltage gradient had significant effects on Dvalue and Zvalue ( p < 0.05). In order to model the survival behavior of Byssochlamys fulva, due to the nonlinearity of the curves, Weibull model gave more accurate estimation compared to classical first-order model.