Ohmic heating of meats: Electrical conductivities of whole meats and processed meat ingredients

The ohmic heating rate of a food is highly influenced by its electrical conductivity (sigma). A survey of sigma values of commonly used meat ingredients when dispersed as 5% (w/w) aqueous solutions/suspensions was undertaken. A subset was further investigated at typical usage levels in solution/suspension, and/or when incorporated into beef blends, while sigma of selected cuts from five meat species (beef, pork, lamb, chicken and turkey) was also measured. Measurements were made from 5 to 85 degrees C and showed a linear increase in sigma values with increasing temperature. In processed beef, addition of sodium chloride and phosphate (P22) caused a significant increase in sigma which in turn would lead to an increase in ohmic heating rates. Furthermore, whole meats with lower endogenous fat or processed meats with the least added fat displayed higher sigma and reduced ohmic heating times. In beef maximum sigma was observed when fibres were aligned with the current flow. (C) 2009 Elsevier Ltd. All rights reserved.