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ELECTRICAL CONDUCTIVITY of APPLE and SOURCHERRY JUICE CONCENTRATES DURING OHMIC HEATING
Author(s) -
ICIER FILIZ,
ILICALI COSKAN
Publication year - 2004
Publication title -
journal of food process engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 45
eISSN - 1745-4530
pISSN - 0145-8876
DOI - 10.1111/j.1745-4530.2004.tb00628.x
Subject(s) - joule heating , ohmic contact , electrical resistivity and conductivity , thermal conduction , chemistry , analytical chemistry (journal) , voltage , thermodynamics , electrical resistance and conductance , current (fluid) , conductivity , materials science , electrode , composite material , chromatography , electrical engineering , physics , engineering
Ohmic heating is based on the passage of electrical current through a food product that serves as an electrical resistance. In this study, apple and sourcherry concentrates having 20–60% soluble solids were ohmically heated by applying five different voltage gradients (20–60 V/cm). the electrical conductivity relations depending on temperature, voltage gradient and concentration were obtained. It was observed that the electrical conductivities of apple and sourcherry juices were significantly affected by temperature and concentration (P < 0.05). the ohmic heating system performance coefficients (SPCs) were defined by using the energies given to the system and taken up by the juice samples. the SPCs were in the range of 0.47–0.92. the unsteady‐state heat conduction equation for negligible internal resistance was solved with an ohmic heating generation term by the finite difference technique. the mathematical model results considering system performance coefficients were compared with experimental ones. the predictions of the mathematical model using obtained electrical conductivity equations were found to be very accurate.