Abstract：To explore the feasibility of using the characteristic relaxation parameters of dielectric relaxation behavior to characterize variations in the internal quality of meat foods, the dielectric relaxation behavior of vacuum packaged fresh chicken breast meat stored at 4 and 20 ℃ in the frequency range of 1 MHz–3 GHz was measured as a function of storage time by means of an impedance analyzer. The dielectric spectra were analyzed by the logarithmic derivative method to determine the characteristic relaxation parameters (relaxation strength Δε and relaxation time τ) of the dielectric relaxation behaviors observed in the investigated frequency range. According to the features of each observed dielectric relaxation behavior and the variation of their characteristic relaxation parameters with storage time, the microscopic relaxation mechanism of each dielectric relaxation behavior was determined, and the correlation between the characteristic relaxation parameters and the specific composition, structure, and physicochemical properties of chicken breast meat was established. The results indicate that there existed three primary dielectric relaxations in the investigated frequency range for chicken breast meat, of which the low-frequency one occurring at around 3 MHz was mainly ascribed to interfacial polarization, while the middle-frequency one occurring at around 40 MHz and the high-frequency one at around 400 MHz were ascribed to the orientational polarization of the head group of proteins and tightly bound water, respectively. Both Δε and τ of the low-frequency relaxation increases with storage time at 4 ℃, while those of the middle- and high-frequency relaxations decreased. The two parameters keep constant after days 9–10 of storage, and the turning point was basically consistent with the time of deterioration of chicken breast meat judged by sensory evaluation. The variations in the characteristic relaxation parameters of all these relaxations with storage time at 20 ℃ were similar to those at 4 ℃, but the turning point was at 30 h, which was also consistent with the time of deterioration determined by sensory evaluation. The variation in the lowfrequency relaxation depended mainly on the variation in muscle cells, and the variations in the middle- and high-frequency relaxations were mainly dependent on the degradation of muscle fibres in chicken breast meat. This study evidenced that the characteristic relaxation parameters could effectively reflect the variation in the quality of chicken breast meat during its storage.
2021, Vol. 35 
