Using automatic conductimetry for monitoring spoilage bacteria on chilled pork cutlets

Experimental batches of chilled cutlets of pork have been stored aerobically and surface growth of bacteria was determined by standard aerobic spread-plate counts, and colony counts of pseudomonads on Cetrimid Agar simultaneously with detection times of respective stomached samples in triplicate using a Malthus Microbiological Analyzer at 30 °C, applying general impedance broth and Pseudomonas impedance medium, respectively. To study the effects of storage temperature on growth of spoilage bacteria, numerous samples were kept in successive experiments at 4, 8 or 12 °C. Parameters of the bacterial growth curves were estimated by curve fitting of the colony counts by DMfit programme package of the ComBase softwares, using Baranyi’s dynamic growth model. Linear correlations were found between the respective colony counts and the conductimetric detection times observed in periodic investigations during storage. According to these calibrations, the conductimetric method at 30 °C incubation is able to assess wi...