[Antibacterial effect of aqueous and alcoholic extracts from petal of saffron [Crocus sativus L.] on some foodborne bacterial pathogens]

ABSTRACT

Health concerns due to adverse effects of chemical preservatives have increased public interest to consuming preservative-free products or product containing natural preservatives such as plant extract and their essential oils. In this study the antibacterial effect of aqueous, ethanolic and methanolic extracts from petal of saffron against the most important foodborne pathogens Salmonella typhimurium, Listeria monocytogenes, E. coli O157 H7, Bacillus cereus and Staphylococcus aureus were evaluated. Disk diffusion method was done to screen bacterial sensitivity. The minimum inhibitory concentration [MIC] of extracts were evaluated by agar dilution and broth microdilution method. The most sensitive strain to extracts was S. typhimurium, and the most resistant strains were S. aureus and E. coli O157H7. MICs of all extracts were estimated 40 mgml[-1], against all bacteria using agar dilution method. The aqua and methanolic extracts showed antimicrobial activity against all of bacteria by broth microdilution and MIC estimated 40 mgml[-1], however MIC of ethanolic extracts estimated 40 mgml[-1] for L. monocytogenes, S. aureus and B. cereus, while the MICs for S. typhimurium and E. coli O157H7 were estimated >40 mgml[-1]. The results of this study revealed that the studied extracts might be potential sources of natural antimicrobial agents, and propose their potential application in food system as a natural preservative