Antimicrobial profile of moringa oleifera lam. Extracts against some food – borne microorganisms

The chloroform and ethanol extracts of seeds and leaf of Moringa oleifera were investigated for antimicrobial activity against some selected food – borne microorganisms as a first step in the screening of the extracts for preliminary sanitizing/preservative properties on foods. The preliminary phytochemical screening and antimicrobial assay were carried out using standard procedures. The results of the phytochemical analysis revealed differences in the presence of the phytochemicals among the extracts. Saponins were detected in all the extracts while tannins were only detected in Moringa oleifera leaf chloroform extract. The antibacterial assay results show that M. oleifera leaf ethanol extract exhibited broad spectrum activity against the test organisms with Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterobacter aerogenes susceptible. The MIC values ranged between 2.0 and >4.0mg/ml for all the organisms. M. oleifera seed chloroform extract was only active against E. coli and Salmonella typhimurium. The MIC values ranged between 1.0 and >4.0mg/ml for the tested organisms respectively. Antifungal activity result revealed 100% inhibition in growth of Mucor and Rhizopus species by M. oleifera seed chloroform extract at concentration of 1mg/ml. Standard Ketoconazole (control) inhibited the test organisms by 100% at 0.5mg/ml concertration. The result of this study have shown the potentials of M. oleifera extracts as sanitizers/preservatives by inhibiting the growth of the test organisms, which range from food – borne pathogens to spoilage causing organisms in foods.