Determination of Electrical Conductivity of Cadaver Skeletal Muscle: A Promising Method for the Estimation of Late Postmortem Interval

The electrical conductivity (EC) of extracted muscle fluid has been extensively used to evaluate meat freshness and shelf life in the field of food sanitation for decades. The opposite of freshness is the corruption that increases with time. Based on the freshness/corruption principle, we investigated the relationship between long postmortem intervals (PMIs) and EC in cadaver skeletal muscle. EC values of extracted fluid from rat muscles were measured at different PMIs for 10 days. The results indicate that there was a significant correlation between PMI and EC, and the data fit well to the cubic polynomial regression equation y = - 0.01x 3 + 0.264x 2 -13.657x + 1769.148 (R 2 = 0.925). In addition, the EC of different dilutions of these muscle extracts showed strict quadratic correlation (R 2 = 1) with the dilution ratios, suggesting that EC can be measured with very small quantities of muscle sample. Our study suggests that determination of the EC of cadaver skeletal muscle extracts may be a useful method for estimating long PMIs.