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Submitted to: Journal of Food Measurement and Characterization
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/9/2015 Publication Date: 2/21/2015 Citation: Trabelsi, S. 2015. Variation of the dielectric properties of chicken breast meet with frequency and temperature. Journal of Food Measurement and Characterization. doi: 10.10007/s11694-015-9235-6. Interpretive Summary: Quality of chicken meat is of interest to both producers and consumers. Quality is often assessed through measurement of physical properties including color, pH, water holding capacity, drip loss, cook yield and texture. The procedures for determining these quality factors are lengthy and tedious and often require costly instrumentation. Chicken meat is composed on average of 70% water, 20% proteins, and 5% lipids. Dielectric properties of materials are the electrical characteristic that determines their interaction with electric fields. If good correlations between quality factors and the dielectric properties of chicken meat can be found, the quality of the meat could be sensed rapidly with suitable instruments that sense the dielectric properties. Because water is the major component in chicken meat, and water has higher dielectric properties than the other components, dielectric spectroscopy, the measurement of dielectric properties over a range of frequencies could be useful for rapid assessment of chicken meat quality. Therefore, the dielectric properties of fresh chicken breast meat were measured over the frequency range from 200 MHz to 20 GHz at temperatures between -20 and +25 degrees C with an open-ended coaxial-line probe to determine its dielectric behavior with respect to frequency and temperature. At a given temperature, the frequency dependence of the dielectric constant revealed two relaxations while those of the dielectric loss factor are dominated by ionic conduction in the lower frequency range and a broad dipolar relaxation at higher frequencies. At a given frequency, the temperature dependence revealed a sharp increase of dielectric properties at about 0 oC which is typical of materials with high water content and indicates the transition from ice-like behavior to liquid-like behavior. The study identified the dielectric behavior as influenced by frequency and temperature and showed the combined influence of water binding, ionic conduction, and dipolar relaxation in determining these properties. Further studies are needed to assess the usefulness of dielectric properties in sensing quality of chicken meat. Successful sensing of quality by rapid measurements would be of benefit to processors, marketers and consumers. Technical Abstract: Dielectric properties of chicken breast meat were measured with an open-ended coaxial-line probe between 200 MHz and 20 GHz at temperatures ranging from -20 oC to +25 oC. To ensure temperature uniformity between the different components of the measurement assembly, the measurements were performed in a temperature-controlled chamber. At a given temperature, the frequency dependence of the dielectric constant reveals two relaxations while those of the dielectric loss factor are dominated by ionic conduction in the lower range and a broad dipolar relaxation at higher frequencies. At a given frequency, the temperature dependence reveals a sharp increase of dielectric properties at about 0 oC which is typical of materials with high water content and indicates the transition from ice-like behavior to liquid-like behavior. Three-dimensional representations of the dielectric properties as a function of frequency and temperature show the combined influence of water binding, ionic conduction, and dipolar relaxation. |
