Dielectric Properties and Thermal Conductivity of Marinated Shrimp and Channel Catfish

Abstract

ABSTRACT Peeled shrimp ( Peneaus spp.) and channel catfish ( Ictalutus punctatus ) fillets were either mixed with commercial lemon pepper marinade and vacuum tumbled at 4°C for 30 min or soaked in 2% tripolyphosphate solution overnight. Dielectric constant and loss factor of marinated seafood and the penetration depth of microwaves were functions of temperature. When cooking temperature increased, the dielectric constant increased, while the loss factor and depth of penetration decreased. Because of the large variation in thermal conductivity measured for individual shrimp, no correlation between thermal conductivity and temperature was found. At constant temperature, thermal conductivity of 2% sodium tripolyphosphate‐treated shrimp was higher than that of both marinated and nonmarinated shrimp as a result of higher moisture content. However, no difference in thermal conductivity was found between marinated and nonmarinated shrimp or catfish.