Antimicrobial And Antioxidant Potentials Of Some Essential Oils Against Spoilage Microorganisms

Abstract

This study evaluates the antioxidant and antimicrobial activities of essential oils (EOs) from four Lamiaceae species: thyme, rosemary, oregano, and sage. Antioxidant potential was assessed through various assays, including DPPH radical scavenging, reducing power activity (RPA), and total antioxidant capacity (TAC). Antimicrobial activity was tested against five pathogenic bacteria (Staphylococcus aureus, Bacillus cereus, Listeria innocua, Pseudomonas aeruginosa, and Escherichia coli) and a yeast strain (Candida albicans). The results of the three antioxidant activity tests indicated that the potency of antioxidants increases in direct proportion to the concentration of essential oils. Oregano EO demonstrated the strongest DPPH scavenging activity and reducing power, surpassing standard antioxidants like ascorbic acid. Therefore, oregano and thyme EOs exhibited excellent antimicrobial properties against microbial strains tested, outperforming rosemary and sage EOs. These findings indicate that oregano and thyme essential oils possess considerable promise as natural preservatives in food and pharmaceutical applications, which may lead to the replacement of synthetic preservatives with plant essential oils.