Comparative analysis of chemical composition, antimicrobial and antioxidant activity of citrus essential oils from the main cultivated varieties in China

Abstract In this work, the chemical composition, antimicrobial and antioxidant activities of fourteen species of citrus essential oils (EOs) from the main cultivated varieties in China were evaluated and compared. A total of more than 200 components were identified, which are mainly composed of terpenes, alcohols, aldehydes, esters, ketones and acids. Antimicrobial ability of fourteen EOs and seven major components were tested against six bacteria and two yeasts. The susceptibility of Gram-positive bacteria tested was observed to be greater than Gram-negative bacteria, and the yeasts tested were relatively more susceptive than bacteria. Three groups (Strong, Medium and Weak) were divided according to the antimicrobial ability. The EOs of Citrus Changshan huyou B. Chang and Citrus. medica var. sarcodactylis Swin exhibited the strongest antimicrobial activity against all tested strains. Linalool showed the strongest antimicrobial activity against all microorganisms except Pseudomonas aeruginosa. Three characters and tendencies were found out to correlate chemical composition with antimicrobial activity of different citrus essential oils. The EOs of Citrus aurantium L and Citurs medica var. sarcodactylis Swing showed strong ABTS radical scavenging, and the EOs of Citurs medica var. sarcodactylis Swing and Citrus Changshan huyou B. Chang exhibited strong free radical scavenging activity.