Clove (Syzygium aromaticum) leaf represents a valuable underutilised plant resource with significant potential for essential oil production. This study characterised clove leaf oil (CLO) from fallen leaves using a standard physicochemical analysis and GC-MS evaluation of phytochemicals. Subsequently, the study evaluated antimicrobial efficacy against four mastitis-associated microorganisms (Staphylococcus aureus ATCC 6538P, Escherichia coli ATCC 25922, Candida albicans ATCC 14053, and Saccharomyces cerevisiae ATCC 9763) using agar well diffusion and broth microdilution methods.
Steam distillation yielded 2.05% essential oil from fallen leaves. Phytochemical analysis identified eugenol as the dominant compound (58.59%), alongside β-caryophyllene, eugenyl acetate, and other bioactive constituents (30 identified compounds). The optimal emulsion formulation at a 1:4 ratio (CLO: Tween 80) resulted in a visually clear emulsion with a transmittance exceeding 90%.
At 15% concentration, CLO produced inhibition zones comparable to 10% povidone iodine against C. albicans (12.93 vs 13.42 mm), S. cerevisiae (16.20 vs 16.11 mm), greater against S. aureus (14.88 vs 13.49 mm), but smaller against E. coli (12.28 vs 14.14 mm), with MIC values of 3.75-5% and MBC values of 7.5-15%, indicating predominantly bacteriostatic activity.
These findings demonstrate that CLO represents a promising natural alternative for routine teat disinfection in sustainable dairy farming operations.