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Electrical Conductivity and Physical Properties of Surimi–Potato Starch under Ohmic Heating
Author(s) -
Pongviratchai P.,
Park J.W.
Publication year - 2007
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1750-3841.2007.00524.x
Subject(s) - potato starch , starch , joule heating , electrical resistivity and conductivity , conductivity , moisture , materials science , ohmic contact , texture (cosmology) , water content , analytical chemistry (journal) , composite material , chemistry , food science , electrical engineering , chromatography , image (mathematics) , geotechnical engineering , layer (electronics) , artificial intelligence , computer science , engineering
Electrical conductivities of Alaska pollock surimi mixed with native and pregelled potato starch at different concentrations (0%, 3%, and 9%) were measured at different moisture contents (75% and 81%) using a multifrequency ohmic heating system. Surimi‐starch paste was tested up to 80 °C at frequencies from 55 Hz to 20 KHz and at alternating currents of 4.3 and 15.5 V/cm voltage gradient. Electrical conductivity increased when moisture content, applied frequency, and applied voltage increased, but decreased when starch concentration increased. Electrical conductivity was correlated linearly with temperature ( R 2 ≈ 0.99). Electrical conductivity pattern (magnitude) changed when temperature increased, which was clearly seen after 55 °C in the native potato starch system, especially at high concentration. This confirms that starch gelatinization that occurred during heating affects the electrical conductivity. Whiteness and texture properties decreased with an increase of starch concentration and a decrease of moisture content.