A study on the antibacterial effects of ethanolic and methanolic extracts of Saffron (Crocus sativus L.) on some food borne pathogens

Control of food borne diseases is a major concern and due undesirable side effects of chemical preservatives, there is more tendencies to natural preservatives such as spices for this purpose. Saffron is the most expensive spice that is is used as coloring and flavoring agent in foods. The aim of the present study was investigate antibacterial effects of hydro alcoholic extracts of saffron against pathogenic bacteria especially food poisoning species. For this purpose, one gram of finely powdered saffron was mixed with 10 ml of 2:8 (v/v) water- alcohol (ethanol or methanol) solution and mixed gently. Following incubation at room temperature, the suspension was centrifuged and the extract of saffron was harvested and dried. Sterile blank discs were saturated with extracts and their effects were evaluated in standard disc diffusion assay against six gram positive and six gram negative bacterial species. Simultaneously, the effect of standard antibiotics was evaluated against tested bacteria. The results revealed that Staphylococcus aureus, Bacillus anthracis, Bacillus cereus, Listeria monocytogenes and Brucella melitensis were the most susceptible species to ethanolic and methanolic extracts of saffron while Proteus mirabilis and Salmonella Typhi were resistant. The antibacterial effects of extracts were noticeable with regard to the standard antibiotics. All of the susceptible species in this study are important food borne pathogens and it is possible to use saffron as a natural preservative in food industry in order to control food borne pathogens.