30D-5 |
Modeling the dielectric properties of meats as a function of temperature and composition |
O. SIPAHIOGLU1, S. A. Barringer, and C. Bircan. (1) Dept. of Food Science & Technology, Ohio State Univ., 2015 Fyffe Rd., Columbus, OH 43210 Dielectric properties of foods help determine heating patterns and rates during microwave processing. Therefore, dielectric properties of meats should be studied. The objective of this study was to generate predictive equations for the dielectric properties of meats at 0-70°C as a function of temperature, moisture and ash content. The dielectric properties of raw beef, chicken (thigh and breast), salmon, perch, cod and nine ham samples with different moisture (38.2-69.9%) and ash (1.82-6.80%) contents were measured at 2450MHz using an open ended coaxial probe and a network analyzer. Moisture and ash contents of meats are from literature. Moisture contents of hams were measured using a vacuum oven. Their ash contents are estimated from their salt contents that were measured using Volhard method. Multiple regression equations were generated using JMPin software. Ham was separated from other meats because of its large data points. The dielectric properties of meats excluding ham can be modeled by: k′=6.49–0.0748•T+0.689•M R2adj=0.82 k′′=-608–0.107•T+0.00177•T2+12.6•M–0.0839•M2+279•A–122•A2 R2adj=0.89 The dielectric properties of ham can be modeled by: k′=-24.8+0.0344•T+1.05•M–0.970•A R2adj=0.81 k′′=-28.9–0.120•T+0.510•M+6.72•A+0.107•A•T–0.533•A2 R2adj=0.79 Dielectric constant of the meats decreased with temperature and increased with moisture. Dielectric constant of ham increased with temperature and moisture and decreased with ash content. Dielectric loss factor of meats first decreased then increased with temperature. Dielectric loss factor of hams increased with temperature. With this comprehensive model, the dielectric properties of meats can be estimated without actually measuring them and this information can be used in modeling temperature profiles and heating rates in the microwave oven.
Session 30D, Food Engineering: Physical and chemical properties
|