Calamondin (Citrus microcarpa) Peel Essential Oil: Physicochemical, Chemical, and Biological Properties

Calamondin (Citrus microcarpa) peel essential oil (CmEO) contains bioactive compounds with potential uses in food preservation, cosmetics, and aromatherapy. This study investigates its chemical composition, antioxidant properties, and antibacterial activity to evaluate its potential as a natural preservative. CmEO was obtained through steam distillation, and its chemical composition was characterized by gas chromatography–mass spectrometry (GC-MS). Its antioxidant potential was evaluated using both DPPH and ABTS radical scavenging assays, while antibacterial effects were tested against Staphylococcus aureus, Escherichia coli, Salmonella enteritidis, and Bacillus cereus through the disk diffusion method. GC-MS analysis identified D-Limonene as the predominant compound, accounting for 95.56% of the total composition. The essential oil (EO) exhibited strong antioxidant activity, demonstrating remarkable antioxidant potential, achieving IC50 values of 9.46 mg/mL in the DPPH assay and 13.95 mg/mL in the ABTS assay. Antibacterial evaluation demonstrated notable antimicrobial efficacy, particularly against Staphylococcus aureus, evidenced by a distinct zone of inhibition measuring 15.73 mm. The findings suggest that CmEO possesses promising antioxidant and antibacterial properties, supporting its potential application as a natural preservative in food and other industries. The findings of this study demonstrate CmEO’s promising use as a natural replacement for synthetic preservatives, supporting the advancement of safer and more sustainable preservation strategies.