Chemical Composition and Antibacterial Activity of Bergamot Peel Oil from Supercritical CO2 and Compressed Propane Extraction

Abstract

Essential oils are widely used as flavors and fragrances in the food, cosmetic and pharmaceutical industries, especially the bergamot peel oil due to the high polyphenols content, compared to other citrus species. Two types of polyphenols present in bergamot peel oil, brutieridin and melitidin, are directly related to cholesterol biosynthesis inhibition in a similar way as the statins. In this context, this work reports the extraction yields of bergamot peel oil obtained by supercritical carbon dioxide and compressed propane, together with the antimicrobial activity. The experiments were conducted at 55°C and 350 bar (density 0.881kg/m3) for carbon dioxide and at 55 °C and 40 bar (density 0.441 kg/m3) for propane. Regarding the antimicrobial activity, the minimum inhibitory concentrations of bergamot oil were effective for the gram-positive bacteria growth inhibition, Staphylococcus aureus at 31.25 µg.mL-1 of bergamot oil, while 500 µg.mL-1 of oil extract was necessary to afford gram-negative bacterium (Escherichia coli) inhibition.