Examining the possibility of producing natural microbicides and antioxidant agents for food and cosmetic uses from the essential oils of Laurus nobilis (laurel), Syzygium aromaticum (clove), and Cinnamomum verum (cinnamon)

The objectives of this study were to evaluate the chemical composition, antioxidant and microbicide properties, and cytotoxic effects of essential oils acquired from Laurel (Laurus nobilis), Clove (Syzygium aromaticum), and Cinnamon (Cinnamomum verum) by hydrodistillation. GC-MS analysis identified 1,8-cineole (48.50 %), eugenol (49.49 %), and cinnamaldehyde (65.34 %) as the major constituents of laurel, clove, and cinnamon essential oils, respectively. Antioxidant capacity, assessed by ABTS⁺ and DPPH assays, revealed that cinnamon essential oil exhibited the highest inhibition percentage. Antimicrobial testing showed cinnamon oil was most effective against tested pathogens, with an average inhibition zone of 28 mm. On the other hand, cytotoxicity was evaluated using the MTT assay on L-929 fibroblast cells, and no harmful effects were observed for clove and cinnamon oils. The protective effect of the oils has been tested against total mesophilic aerobic bacteria (TMAB) and yeast-mold (YM) count in a preservative-free tomato paste model food environment with a 25-day storage period. At the end of 25 days, the control group had 3 × 10² cfu/g excess colony formation, but the samples treated with 1.5 % concentration had 1.5 × 10¹ cfu/g mean count. Furthermore, a hand sanitizer formulation containing these oils suppressed microorganisms by 85 %, whereas the addition of isopropyl alcohol (25 %) increased the activity to 98 %. These findings demonstrate that clove and cinnamon essential oils possess strong inhibitory effects against microbial growth and oxidation, supporting their potential as natural alternatives to synthetic preservatives and disinfectants.