Chemical profile, antifungal, antiaflatoxigenic and antioxidant activity of Citrus maxima Burm. and Citrus sinensis (L.) Osbeck essential oils and their cyclic monoterpene, DL-limonene.

The study deals with antifungal, antiaflatoxigenic and antioxidant activity of Citrus maxima and Citrus sinensis essential oils (EOs) and their phytochemical composition. The EOs were obtained by hydrodistillation and their chemical profile was determined through GC and GC-MS analysis. Both the EOs and their 1:1 combination showed broad fungitoxic spectrum against different food contaminating moulds. The EOs and their combination completely inhibited aflatoxin B(1) (AFB(1)) production at 500 ppm, whereas, DL-limonene, the major component of EOs showed better antiaflatoxigenic efficacy even at 250 ppm. Both the oils exhibited antioxidant activity as DPPH free radical scavenger in dose dependent manner. The IC(50) for radical scavenging efficacy of C. maxima and C. sinensis oils were to be 8.84 and 9.45 microl ml(-1), respectively. The EOs were found non-mammalian toxic showing high LD(50) for mice (oral, acute). The oils may be recommended as safe plant based antimicrobials as well as antioxidants for enhancement of shelf life of food commodities by checking their fungal infestation, aflatoxin production as well as lipid peroxidation.