Purpose: The purpose of this study was to evaluate the antibacterial activities of Clitocybe nuda extract on foodborne pathogens and its stability at different temperatures and pHs.
Methods: Clitocybe nuda mushroom was dried, ground, extracted in 95% ethanol and finally redissolved in deionized water. The antimicrobial activities were evaluated by testing the minimum inhibitory concentration (MIC) on Listeria monocytogenes, Salmonella Typhimurium, E. coli O157:H7, and Staphylococcus aureus. The extract was treated at 4, 25, 72, 100, and 121 °C for 15 min and at pH 4-10 for stability test. Results were calculated and compared using ANOVA.
Results: The mushroom extract showed strong antimicrobial activities on the tested foodborne bacteria. The MIC50 were 77.04 ± 3.05 mg/ml for Listeria monocytogenes and 77.05 ± 1.73 mg/ml for Salmonella Typhimurium. The extract is heat stable and the antibacterial activities between different temperature treated samples were not significantly different (P ≥ 0.05). The change of pH had no negative effect on the antibacterial activities of this extract.
Significance: The results indicated that the extract can effectively control the growth of foodborne pathogens. There is a great potential use in foods due to its stability at high temperature and in a wide range of pH.