Efficacy of chemically characterized Ocimum gratissimum L. essential oil as an antioxidant and a safe plant based antimicrobial against fungal and aflatoxin B1 contamination of spices

The paper reports the essential oil (EO) of Ocimum gratissimum as plant based preservative and recommends its application as a nontoxic antimicrobial and antiaflatoxigenic agent against fungal and aflatoxin contamination of spices as well their shelf life enhancer in view of its antioxidant activity. The EO exhibited antifungal activity against fungal isolates from some spices and showed better efficacy as fungitoxicant than prevalent fungicide Wettasul-80. The EO also completely checked the aflatoxin B1 (AFB1) synthesis by the toxigenic strains LHP-6 and LHP-10 of A. flavus isolated from Piper nigrum and Myristica fragrans respectively at 0.6 μl/ml and 0.5 μl/ml, respectively. In addition, EO showed antioxidant activity through DPPH free radical scavenging and β-carotene-linoleic acid bleaching assay. Methyl cinnamate (48.29%) and γ-terpinene (26.08%) were recorded the major components of the oil through GC-MS analysis. The EO was found non-mammalian toxic showing high LD50 (11622.67 μl/kg) during oral toxicity on mice.