Antibacterial activity of <i>Myrtus communis</i> L. essential oil against <i>Escherichia coli</i> O157 in Egyptian fresh soft cheese in relation to its chemical components

Abstract

Foodborne outbreaks associated with <i>Escherichia coli</i> O157 in the production of fresh cheese typically resulted in several bacterial infections in humans. Therefore, a number of additives-particularly natural additives-were employed to inhibit the growth of these microorganisms. In folk medicine around the world, <i>Myrtus communis</i> L. is a commonly employed traditional plant for treating an assortment of ailments. <i>M. communis</i> essential oil (McEO) is utilized for cosmetic formulations and food additives for covering off some foods’ flavors. In this study, the antibacterial effect of McEO against <i>E. coli</i> O157 in Egyptian fresh soft cheese has been evaluated. The results showed that McEO exhibited inhibitory activity (MIC) against <i>E. coli</i> O157 at concentration of 0.8% (v/v) and bactericidal effect (MBC) at concentration of 3.2% (v/v). The bioactive components of McEO were characterized via the GC-FID and GC-MS analysis. Twenty-one volatile compounds were identified accounting 98.52% of the total oil mass. Terpenes represented overall identified constituents especially monoterpenes (94.99%). The three antibacterial compounds 1,8-cineole, α-pinene, and D-limonene were assigned as the primary components with corresponding relative concentrations of 42.18, 38.74, and 6.51%. Current findings provided evidence to support the idea of employing McEO as an <i>E. coli</i> O157 inhibitor in manufacturing of the Egyptian fresh soft cheese.