Survey on impedance correlation with plate count method, pH, and TVN in evaluation of microbial load of minced beef

Measuring the total microbial count of cow minced meat with the conventional method and comparing the result with standard limits is one of the routine tests. Achieving the results of total microbial count in minimum time is really important for confidence from the hygienic quality of products. So impedance- splitting method as a new technique for this purpose was considered in order to receive the results in less time and as soon as possible. The main purpose of the study was to evaluate the correlation between impedance detection times (IDT in hrs), total microbial population (log CFU/g), total volatile nitrogen (TVN) and pH of minced meat. Totally 80 minced meat samples were collected and examined for the total microbial count by reference and impedance - splitting methods, also total volatile nitrogen and pH were measured based on the recommendations of Iran's Standard Institute and Industrial Investigation. Then the calibration curves of methods and their equations were obtained by using Excel software. The calibration curves of methods were elaborated for total microbial count and impedance detection time, demonstrating a good correlation between the two methods in mince neat samples equal to %93/39. Also according to the calibration curves, the correlation between impedance detection time and total volatile nitrogen in all of the samples were equal to %69.8. Also, the correlation between total microbial count and pH was equal to %71/4. According to above-mentioned correlation values, the impedance technique could be only recommended as an alternative method in evaluating the microbial load of the minced meat.