Evaluation of chemical composition and in-vitro antibacterial activity of oregano (Mentha pulegium) growing wild in maku and its inhibitory effect on Staphylococcus aureus in sausage

The use of natural substances that have antibacterial activity could reduce the consumption of chemical and synthetic agents in food industry for inhibition of the growth pathogens. Based on plants attract the main concentration on this topic. Oregano plant that grows in different parts of Iran has antibacterial and antioxidant effects, which due to its flavor can be used in the food industry. The aim of this study was to evaluate the antibacterial effect of Mentha pulegium essence on the growth of Staphylococcus aureus in sausage dough. For this purpose, fresh Mentha pulegium harvested from Maku Mountains and dried at dark and cool place, finally the essence were prepared by using the Clevenger apparatus. The higher compound in Mentha pulegium essence was Pulegone (51/4 %) and the lower substance was Camphene (0.29 %). The antibacterial property of Mentha pulegium was determined by microbroth dilution method in three different levels of essence (0.25, 0.5 and 1 percentage) for measuring the minimal inhibition concentration (MIC) and minimal bactericidal concentration (MBC) at laboratory scale. Results showed that the MIC and MBC amount for this essence against Staphylococcus aureus were obtained 31.26 and 125µg in mL respectively. Also, results documented that the addition of 1 percent Mentha pulegium essence in contaminated sausage dough matrix could statistically inhibit the growth of Staphylococcus aureus. It should be concluded that the addition of Mentha pulegium essence into the contaminated matrix of Sausage dough with Staphylococcus aureus resulted in the inhibition of bacterium and its number until 15 days storage at refrigerator.