Purpose: Comparative evaluation of a new automated assay for the enumeration of total aerobic mesophilic flora in the select food and environmental samples.
Methods: Five replicates of 3 different lots of 15 naturally contaminated foods including meat, poultry, sea foods, fruits and vegetables, dairy, nuts, pet food and environmental samples were processed to enumerate total aerobic mesophilic flora using a new automated assay and aerobic plate count (PCA) reference methods (SMEDP for dairy and AOAC 996.23 for others samples). The logarithmic transformations of final counts were statistically analyzed using t-test (P < 0.05) for the lot-wise comparisons and to establish repeatability of the test and reference methods.
Results: Out of total 46 lot-wise comparative evaluations, the overall calculated bias was 0.02 indicating that there was no significant bias between the test and reference methods. The mean log count differences between the alternative method and reference method for all lot-wise comparisons were within the acceptable range of <0.5 log (0-0.43).
Significance: This new AOAC–PTM approved method provides a faster, accurate and simpler approach for the enumeration of total aerobic flora within 22-28 hours without the need of media preparation, serial dilutions, manual counting, and visual interpretation of results. This new assay provides rapid results with the additional advantages of significant economic labor savings, increasing efficiency and better traceability.