Antibacterial properties of olive leaf extracts extracted by subcritical water method on food borne pathogen

Medicinal herbs contain large secondary compounds that often have important biological activity, and since extracts of plants are widely used in the pharmaceutical, food, and health industries, various extraction methods are very important. One of these herbs is the olive leaf, which has more beneficial properties than other parts due to its phenolic compounds, its antioxidant and antimicrobial effects. The purpose of this study was to determine the optimal conditions for extraction of bioactive compounds in the olive leaf of Minoodasht area of Golestan province, using by subcritical water method and its antibacterial effect on Staphylococcus aureus and Escherichia coli bacteria by the methods of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) and Disc Distribution. Optimum extraction conditions were carried out at temperatures 120-180 ° C, under a pressure corresponding to the extraction temperature and mixing ratio of 1:20, with physicochemical properties (efficiency, turbidity, and brix). Antimicrobial properties (MIC and MBC) of extracts extracted by each and every one (soaking and subcritical water) against Staphylococcus aureus and Escherichia coli bacteria in concentrations of 25-5130 ppm with three replications, the results showed that the effect of high concentrations of bioactive compounds in extracts obtained by the subcritical water method on gram-positive bacteria of Staphylococcus aureus. Also, in the disk diffusion method, resistant gram-negative bacteria of Escherichia coli and Staphylococcus aureus was the most sensitive bacteria.