Study on Total Plate Count Detection in Beverage by 3M Petrifilm^TM Rapid Aerobic Count Plate

The 3M PetriFilm^TM rapid aerobic count plate method (3M test plate method) and filter membrane method were used to quantitatively determine the total number of bacterial colonies in the beverage, and the consistency of the two methods was analyzed. Seven kinds of bacteria including Escherichia coli, Staphylococcus aureus, Paenibacillus ehimensis, Bacillus subtilis, Asia Siamensis, Candida albicans and Aspergillus niger were used to artificially inoculate and test the beverage samples. The experimental results showed that for different strains and different pollution levels, the linear fitting degree of 3M test plate method and filter membrane method was better (determination coefficient R²>0.95). And the recovery rate of 3M test plate method was more than 70%, and the RSD values (2.9%~34.3%) were within the prescribed range of Pharmacopoeia of the People's Republic of China 2020, indicating that 3M test plate method had better accuracy and precision. For the specificity test of bacterial and fungal contamination and the repeatability test of different batches of 3M test plates, the recovery rate of 3M test plate method was more than 70%, and the RSD values (3.6%~34.3%) were within the acceptable range, showing good specificity and repeatability. The results of 3M test plate method and filter membrane method were analyzed by using relatively trueness and accuracy profileanalysis method. The results showed that the two methods had good consistency and equivalence. Based on the above analysis results, 3M test plate method is equivalent to filter membrane method to determine the total number of colonies in beverages.