Valorization of Citrus Leaves: Chemical Composition, Antioxidant and Antibacterial Activities of Essential Oils

The objective of this study was to characterize chemical composition and functional properties of essential oils extracted from leaves ofCitrus sinensisOsbeck,Citrus grandisOsbeck andCitrus aurantifoliaSwingle. The essential oil of theC. sinensisandC. grandisleaves contained 44 compounds, accounted for total percentages of 94.17% and 93.78% of the oils, respectively, whereas the essential oil of theC. aurantifolialeaves had 62 compounds, accounted for 97.19% of the oil. Limonene, beta-pinene, sabinene, beta-ocimene, beta-cubebene, terpinen-4-ol, linalool and nerol were main volatile compounds of the essential oil of theC. sinensisleaves, while the essential oil of theC. grandiscontained high percentages of limonene, alpha-phellandrene, beta-ocimene, beta-caryophyllene, nerol, citronellol, geraniol, geranial and neral. The main volatile compounds of the essential oils of theC. aurantifolialeaves were Limonene, beta-pinene, beta-ocimene, beta-caryophyllene, alpha-terpineol, citronellol and (+)-citronellal. The essential oil of theC. aurantifolialeaves exhibited the strongest scavenging activities (IC50 = 1.21 mg/ml) as compared to those of theC. sinensis(IC50 = 1.49 mg/ml) andC. grandisleaves (IC50 = 2.18 mg/ml). The essential oil ofC. grandisleaves exhibited stronger antimicrobial activities than the essential oils ofC. sinensisandC. aurantifolialeaves. Graphic