Essential Oils as Sustainable Green Preservatives: Enhancing Shelf-Life and Safety of Chicken Drumsticks under Refrigeration

The current study evaluated the antioxidant and antimicrobial potential of ten essential oils (EOs), viz. clove bud, cinnamon bark, ajwain seed, lemon balm leaf, lime peel, jatamansi rhizome, tea tree, thyme, lemon grass leaf and oregano-for food preservation applications. Antioxidant activity was assessed using total phenol content (TPC), 2,2-diphenyl-2-picrylhydrazyl (DPPH) assay, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay, and Ferric reducing antioxidant power (FRAP) assay, while antimicrobial efficacy was tested against Escherichia coli, Salmonella Typhimurium, Staphylococcus aureus, and Listeria monocytogenes. Among the tested EOs, thyme (TEO) and cinnamon bark (CBEO) exhibited superior antioxidant activity, comparable to synthetic preservatives butylated hydroxyanisole and butylated hydroxytoluene. Additionally, CBEO and TEO exhibited the strongest antimicrobial effects, as indicated by the zone of inhibition, minimum inhibitory concentration, and minimum bactericidal concentration. Chemical characterisation via Gas chromatography-mass spectrometry/mass spectrometry revealed 9-methoxybicyclo[6.1.0]nona-2,4,6triene (92.48%) and vinyl trans-cinnamate (4.28%) as major compounds in CBEO, while TEO contained 2-methyl-5-(methyl ethyl) (51.97%) and m-cymene (19.65%). Fourier transform infrared spectroscopy analysis confirmed the presence of bioactive functional groups, including phenolics and monoterpenes, which contribute to their antioxidant and antimicrobial properties. These two potential essential oils (2% v/v) effectively preserved the microbiological quality (Total viable counts), lipid oxidation (Thiobarbituric acid reactive substances) levels, and sensory attributes (odour) of raw chicken drumsticks during up to 15 days of storage at 4±1°C, compared with untreated samples. The findings demonstrate that plant-derived EOs (TEO and CBEO) are promising natural alternatives to synthetic preservatives, offering practical solutions for enhancing the safety and shelf life of fresh meat.