Investigation of Long Time Beef and Veal Meat Behavior by Bioimpedance Spectroscopy for Meat Monitoring

Maturation state of meat influences its fibers structure and conductivity and leads to observable changes of its complex impedance. The relationship between the postmortem state and the change of meat impedance has been characterized to serve as a basis for developing an in vitro measurement method for the freshness of meat. Experimental measurements were carried out for long period of time of 14 days with circular penetrating multielectrodes on beef and veal muscles. The results have been evaluated by means of a modified Fricke model, which considers distributed electric parameters in the biological tissue and leads therefore to a good fitting performance. Beef meat shows a higher extracellular resistance and a higher membrane capacitance than veal due to the fact that beef muscle fibers are thicker and less juicy than veal muscle fibers. The evolution of model parameters is correlated with the expected behavior with aging. The parameter R_e that represents extracellular fluids decreases considerably from day 6 to day 14 about 7%-25% depending on the muscle type. The capacitive element C that corresponds to the insulating cell membranes decreases with time from day 6 to day 14 about 5%-17% depending on the muscle type. The parameter R_i that represents intracellular fluids increases from day 6 to day 14 about 3%-12% depending on the muscle type.