ELECTRICAL CONDUCTIVITY of SELECTED JUICES: INFLUENCES of TEMPERATURE, SOLIDS CONTENT, APPLIED VOLTAGE, and PARTICLE SIZE

A device was developed to determine the electrical conductivities of foods under ohmic or conventional heating conditions. Orange and tomato juices (serum and various solids contents) were tested in the device. the electrical conductivity of juices increased with temperature and decreased with solids content. the temperature dependence of conductivity was linear, both under conventional and ohmic heating. Experiments on suspensions of carrot juice solids, and polystyrene spheres in sodium phosphate solution showed an increase in electrical conductivity of the suspension with decreasing particle size.