Dielectric characterization of hen eggs during storage

Changes of the dielectric parameters of fresh hen eggs during storage were investigated for the development of a method to assess the main quality indices. Dielectric constant (epsilon') and loss factor (epsilon '') were measured in the frequency range 20-1800 MHz using an open-ended coaxial probe on thick albumen and yolk of eggs after 1, 2, 4, 8 and 15 days of storage at room temperature. Tests were also carried out at the 9th day of storage to compare dielectric properties of thick and thin albumen. Statistical analysis was performed at 20, 100, 400, 900 and 1800 MHz. Thick and thin albumen showed slight differences in dielectric properties but significant only for epsilon '' at 900 MHz. Dielectric constant and loss factor of yolk generally increased with the storage time. The maximum increment from the Ist to the 15th days of storage (22%,) was registered for epsilon '' at 20 MHz. Methods based on the comparison between the experimental epsilon '' and calculated values by means of conductivity and frequency can potentially be used in predicting eggs' age. (C) 2007 Elsevier Ltd. All rights reserved.