Purpose: Performance of three methods for the recovery of Yeast and Molds on a variety of products
Methods: Four groups were evaluated: processed meat, dairy products, processed food and environmental samples. Thirty samples per matrix were analyzed. Samples were artificially contaminated with a mix of Aspergillus niger (50-100 CFU/sample) and Saccharomyces cerevisiae (50-100 CFU/sample). Samples were diluted and plated on 3M RYM and Mold, 3M™ Petrifilm™ Yeast and Mold (YM) and Potato Dextrose Agar. Samples were incubated for 48 hours for RYM and 120 hours for YM and PDA. Results were analyzed using a paired t-test at 95% of confidence.
Results: A total of 1,080 samples were analyzed. Recovery of molds was as follows: 2.30 logs CFU for 3M Petrifilm RYM, 2.32 log CFU for 3M Petrifilm YM and 2.17 log CFU for Potato Dextrose Agar. Media recovery of yeast was 3.02 log CFU for 3M Petrifilm RYM, 2.97 logs CFU for 3M Petrifilm YM and 2.52 log CFU for the traditional method. Statistical differences were not found between the three methods (P>0.05).
Significance: 3M Petrifilm Rapid Yeast and Mold and 3M Petrifilm Yeast and Mold Petrifilm Plates provide reliable and accurate results and can be used for Yeast and Mold enumeration in finished products such as dairy, processed meats, processed foods as well as environmental sampling.