Electrical Properties of Fish Mince During Multi‐frequency Ohmic Heating

Abstract

ABSTRACT A multi‐frequency ohmic heating system with 30 Hz∼1 MHz range which could deliver 250 watts was developed for measuring electrical conductivity and absolute dielectric loss of food samples. Pacific whiting surimi paste and stabilized mince in the 20∼70°C range were tested at frequencies from 55 Hz to 200 kHz. Sample impedance decreased slightly with frequency. The DC electrical conductivity (σ dc ) and absolute dielectric loss (ε″) of Pacific whiting surimi paste increased with temperature and salt concentration; adc and ε″ of the stabilized mince increased with temperature. Empirical models of electrical properties for surimi paste (moisture content 79% and salt at 1, 2 or 3%) and stabilized mince (77% moisture and 0.74% salt) were derived. Electrolytic corrosion diminished with frequency.