Determination of bactericidal efficacy of essential oil extracted from orange peel on the food contact surfaces

Essential oil was extracted from peels of sweet orange fruits by supercritical technique and the resulting compounds were analyzed by gas chromatography. After emulsifying with tween-20 in sterile water, the antibacterial efficacy against Vibrio parahaemolyticus, Salmonella typhimurium, Escherichia coli, and Staphylococcus aureus, which were inoculated on the surfaces of samples of stainless steel and plastic cutting board pieces, was determined. Sterile water was used as control and two commercial detergents, A and B, were used as comparative agents. Compared with control, more than 5-log reduction was obtained against V. parahaemolyticus at 1% and S. typhimurium and E. coli at 2.5% of the essential oil. No significant reduction (P ≥ 0.05) was obtained against S. aureus even at 5%. Antibacterial activities of the essential oil and detergent B were significantly higher (P < 0.05) than detergent A and control. In addition, significantly higher (P < 0.05) reductions were obtained on stainless steel than plastic cutting boards. Our results showed that the extracted orange oil could effectively inactivate V. parahaemolyticus, S. typhimurium, and E. coli but not S. aureus, on the food contact surfaces.