Chemical profile, antimicrobial and antioxidant activities of Citrus reticulata and Citrus clementina (L.) essential oils

The present investigation reports on the chemical composition of three citrus fruit essential oils (mandarin [Citrus reticulata], wilking [Citrus reticulata cultivar wilking] and clementine [Citrus clementina]) from Algeria, and examines their antioxidant and antimicrobial activity against eight spoiling and pathogenic microorganisms. The chemical composition of the essential oils obtained from the peels, by hydrodistillation, was analyzed by Gas chromatography-mass spectrometry (GC-MS). 12 compounds were identified and limonene was the common major component for the three essential oils (77- 97%).The disc agar diffusion technique indicated mandarin essential oil (EO), as evidenced by their zones of inhibition, as the best growth inhibitor followed by clementine and wilking essential oils. Among the tested microorganisms, the oils was very active against Candida albicans, Escherichia coli, Lysteria innocua, Methicillin-Resistant S. aureus and Staphylococcus aureus with an inhibition zone varied from 9.16 to 27.63 mm. Minimal inhibitory concentration (MIC) of different EOs was for all 5 qL/mL against the sensitive microorganisms studied. All citrus oils studied exhibited antioxidant activity as DPPH free radical scavenger and reducing power in dose dependent manner. Mandarin oil showed the strongest activity compared to clementine and wilking essential oils. The oils may be recommended as safe plant based antimicrobials as well as antioxidants for enhancement of shelf life of food commodities.