ANTIBACTERIA ACTIVITY OF ESSENTIAL OIL BLEND FROM GARLIC (ALLIUM SATIVUM) AND TANGERIN FRUIT (CITRUS RETICULUM) PEELS ON SALMONELLA TYPHI AND STREPTOCOCCUS SPECIES
Abstract
This study aimed the combined antibacterial activity of essential oil blends derived from garlic (Allium sativum) and tangerine (Citrus reticulata) peels against Salmonella typhi and Streptococcus species. Using agar well diffusion, paper disc diffusion, and broth microdilution methods, the antimicrobial efficacy and minimum inhibitory concentration (MIC) of the oil blends were assessed. Results showed that ethanol extracts of the blends exhibited stronger antibacterial activity than aqueous extracts, with inhibition zones up to 28 mm for Streptococcus species and 19 mm for Salmonella typhi at full concentration. Streptococcus species demonstrated greater susceptibility compared to Salmonella typhi, with MIC values as low as 25% for ethanol extracts of both garlic and tangerine oils, while aqueous extracts required higher concentrations (50–75%). The enhanced activity of ethanol extracts is attributed to the efficient extraction of bioactive compounds like allicin and D-limonene, which disrupt bacterial cell membranes. These findings highlight the potential of garlic and tangerine peel essential oil blends as natural, cost-effective alternatives to synthetic antibiotics, particularly against Gram-positive pathogens, though further optimization is needed for broader efficacy against Gram-negative bacteria like Salmonella typhi.
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