Measurement of the freshness of fish by impedance spectroscopy (Part 1): electrical characteristics of fish and selection of high frequency freshness indices

摘要

As one of the rapid and simple evaluation methods instead of the sensory evaluation for fish freshness, we tried to develop an electrical evaluation method using a high frequency range above 10kHz. Material evaluation by frequency characteristics of electrical impedance and its parameter is called impedance spectroscopy. In case of tissue, information of the deterioration such as damage and softening can be obtained by the method. In this paper, we investigated the variation with ice storage time of the frequency characteristics of resistance and reactance and complex impedance trajectories for muscle of red sea bream. As the results. we selected the radius of Cole-Cole circular arc calculated from the high frequency range 10kHz～1MHz, the resistance ratio and the difference of 10kHz and 1MHz, the central frequency of relaxation and peak value of reactance for the freshness indices.