ANTIBACTERIAL ACTIVITY OF LEMON (CITRUS LEMON L.), MANDARIN (CITRUS RETICULATA L.), GRAPEFRUIT (CITRUS PARADISI L.) AND ORANGE (CITRUS SINENSIS L.) ESSENTIAL OILS

Many complex processes are involved in food deterioration, and despite modern techniques of preservation, excessive amounts of foods are still lost, mainly through the action of microorganisms. The growing preference for natural foods has led to a tendency to diminish the use of chemical additives and for the food industry to search for alternative antimicrobial agents within natural systems. The aim of this work was to determine the effectiveness of the essential oils (EOs) of lemon (Citrus lemon L.), mandarin (C. reticulata L.), grapefruit (C. paradisi L.) and orange (C. sinensis L.) to inhibit the growth of some bacteria commonly used in the food industry, (Lactobacillus curvatus, L. sakei, Staphylococcus carnosus and S. xylosus) or related to food spoilage (Enterobacter gergoviae and E. amnigenus). The agar disc diffusion method was used to determine the antibacterial activities of the oils. All EO studied had some inhibitory effect on the six bacteria tested. Lemon EO showed the highest inhibition effect upon S. carnosus, E. gergoviae and E. amnigenus while grapefruit EO showed the highest inhibition effect upon S. xylosus, L. curvatus and L. sakei. Orange and mandarin EOs had the lowest inhibition effect upon the six bacteria tested.