Abstract

The study evaluates the chemical composition, antioxidant and antimicrobial effects properties of essential oil of Citrus limon (Eureka) extracted by hydrodistillation. The composition of this oil was analysed by GC/MS for 30 constituents, which accounted for 97.8% of total oil. The main components were limonene (61.3%) followed by β-pinene (9.7%), α-citral (4.2%) and α-terpinene (3.8%). Antioxidant activity of the C. limon essential oil was evaluated by using DPPH radical scavenging and β-carotene-linoleic acid bleaching. In both tests, the oil showed antioxidant property close to that of positive control (α-tocopherol). The essential oil was tested against nine bacteria (two Gram+: Bacillus cereus, Staphylococcus aureus ATCC 29213 and seven Gram-: Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Salmonella enterica, Klebsiella pneumoniae, Enterobacter aerogenes, Serratia marescens, Proteus mirabilis) by using disc diffusion and microdilution methods. C. limon essential oil showed antimicrobial effect against all microorganisms tested. Maximum activity (MIC = 180 μg.ml^-1) was observed against Staphylococcus aureus.

Key words: Chemical composition, diffusion technique, microdilution technique, hydrodistillation, percentage of inhibition.