Development of portable bio-impedance spectroscopy system for measuring porcine meat quality

Based on the principle of bio-impedance spectroscopy, a non-destructive portable bio-impedance prototype system for measuring meat quality was developed. The system consisted of a signal generator unit and a detection unit. The former unit could output sinusoidal signal with automatic frequencies scanning, which is range from 0.1 kHz to 250 kHz. The detection unit included detection electrodes and a gain and phase detector. In this work, the performance of six-needle steel electrodes and four-needle graphite electrodes in detecting bio-impedance was compared. Also, coefficients of variability (CVs) were applied to assess the stability of the system. Experiment showed that the coefficient of variation (CV) of the system was less than 6% if the frequency was above 1 kHz. Intra class correlation (ICC) procedures were applied to assess the reliability of the system due to temperature variability. Values of Ri, Re, C in the system model were reliable with intra class correlations of more than 65%. Furthermore, pork samples were selected to investigate relation between bio-impedance spectroscopy and meat quality attributes, i.e. meat freshness. Results showed that bio-impendence value, real part value of bio-impendence, imaginary part value of bio-impendence and characteristics frequency of pork decreased with the change of meat freshness.