Antimicrobial evaluation of plant essential oils against pathogenic microorganisms: In vitro study of oregano oil combined with conventional food preservatives

Essential oils (EO) are promising natural antimicrobial additives to control microbial pathogens. This stu-dy aims to investigate the antimicrobial activities of plant essential oils and to study the antimicrobial effect of oregano oil (OrO) in combination with food preservatives. The antimicrobial screening showed that Escherichiacoli and Salmonella enterica subsp. enterica serovar Typhimurium (Salmonella ser. Typhi-murium) appeared to be less susceptible to EO, whereas Staphylococcus aureus and Candida albicans were more affected. The Minimum Inhibitory Concentration (MIC) and Minimum Lethal Concentration (MLC) for laurel, cumin, oregano and rosemary oils showed values ranging from 0.078% to 1.25% (v/v). Also, sy-nergic and viability effects of OrO combined with acetic acid (AcA) showed an additive effect against E. coli and C. albicans, while combination OrO + ascorbic acid (Asc) exhibited the same effect over Salmonella ser. Typhimurium and C. albicans. Therefore, oregano oil in combination with preservatives could be used to control the growth of pathogenic microorganisms for food preservatio