Impedance measurement : A rapid and non - invasive approach for monitoring pork meat quality during storage

Abstract

This study investigated correlations between impedance and some bio-indicators of meat freshness, namely total aerobic count (TAC), total volatile base nitrogen (TVB-N) and pH during storage at 4oC. Critical factors influencing impedance measurement such as electrode configurations (bar, ring and needle types), frequencies (20 Hz – 200 KHz), directions of applied electric fields (transverse, longitudinal) were considered. Results indicated a relatively good relationship between measured impedance and bio-indicators with R2 ranging from 0.63 – 0.99, RMSE from 0.10 – 0.57 for TAC; R2 from 0.63 – 0.99, RMSE from 0.28 – 1.43 for TVB-N. Bar and ring electrodes had better performance as compared to needle electrodes. Effects of frequency on impedance were important from 20 Hz–200 KHz and diminished in the higher ranges. Impedance measured at high frequency generally had higher correlations with TAC, TVB-N than values at low frequency. The findings demonstrated that impedance measurement could be a viable, rapid method to assess the quality of stored pork meat.

Keywords Electrical impedance; Meat freshness; Pork meat quality; Frequency; Total volatile base – nitrogen; Total aerobic count