Investigation on the antimicrobial effects of Portulaca oleracea leaves essence and extract on Staphylococcus aureus to reduce nitrate used in meat products

In this study، the antimicrobial effects of Portulaca oleracea leaves essence and extract on Staphylococcus aureus to reduce nitrate used in meat products is investigated. For this purpose، methanol extract and essential oil of Portulaca Oleracea leaves were prepared and chemical composition were determined. Antimicrobial activity of them were investigated with different concentrations (500، 1000، 5000 and 10000 ppm) and 50ppm nitrate solution on Staphylococcus aureus count in sausage at different time intervals: storage for 15، 30 and 45 day at -12°C. The results showed that 83% and 93. 4% of main constituents of the extracts and essence were phenolic compounds and flavonoids، respectively، which exhibit significant bactericidal activity. The results also indicated that MIC of the extract was 10000 ppm and it did not show any bactericidal effect on S. aureus. While the MIC and MBC of essence were respectively 500 and 10000 ppm was considered. Also nitrate concentration used did not show inhibitory effects on the growth of S. aureus. These data indicate that Portulaca Oleracea leaves essence and extract can exhibit antimicrobial activity against Staphylococcus aureus; so it can be considered as an alternative natural preservative in food products.