Antibacterial and antioxidant activity of essential oils from Citrus spp

The antibacterial and antioxidant activities of essential oils from Bitter orange, Sweet orange, Lemon and Mandarin were investigated. The antimicrobial capability of these oils was determined against ten strains of Gram-negative and Gram-positive bacteria, including some phytopathogenic strains. The antibacterial activity of the oils was expressed as minimum inhibitory concentrations (MICs). All oils showed good antibacterial activity against both Gram-negative and Gram-positive bacteria. The MICs for selected oils ranged 15-250 pg/mL. The lowest MICs were 15 pg/mL and 20 pg/mL against Xanthomonas citri strains, respectively. The antioxidant and antiradical scavenging properties of the selected oils were tested by means of l,l-diphenyl-2- picrylhydrazyl (DPPH) assay. All examined oils exhibited a free radical scavenging activity, ranging 20-70% of DPPH inhibition. Lemon oil showed the most antioxidant capacity, with DPPH inhibition rate of 70%. © 2011 Allured Business Media.