Study on impedance characteristics of salted duck egg at low frequency

Salt, oil yielding rate and hardening rate are the main indicators reflecting the salted egg quality.Based on the study of impedance characteristics and physical and chemical property of duck egg white and yolk at low frequency range of 100Hz～12MHz in the process of salting, a feasible test method was developed.Protein species of duck egg white and yolk before and after salting was analyzed and its equivalent circuit was established. The reference value of various protein resistance and capacitance were obtained by curve fitting of bode plot, complex admittance plot and real part and imaginary part plot.Changes of characteristic frequency of duck egg white and yolk before and after salting as well as their possible scattering type were determined.It was found that there was a significant regression characteristic between impedance amplitude and salt content, oil yielding rate and hardening rate in the process of salting at 102Hz.