Spice oils as natural antimicrobial agents of food-borne microorganisms.

Abstract

In order to search for new substitutes for sodium nitrite in foods, this research investigated the antimicrobial activity of garlic, clove, onion, and oregano oils against two Gram-positive cocci, Bacillus cereus and Staphylococcus aureus, and one Gram-negative bacillus, Salmonella typhimurium. Garlic oil proved to have the highest antimicrobial activity among the four spice oils using a growth inhibition test of the bacteria on tryptic soy agar (TSA) plates. The minimum inhibitory concentration (MIC) of garlic oil was determined bacillus, Salmonella tvphimurium. Garlic oil proved to have the highest antimicrobial activity among the four spice oils using a growth inhibition test of the bacteria on tryptic soy agar (TSA) plates. The Abstract approved: Bacillus cereus and Staphylococcus aureus, and one Gram-negative clove, onion, and oregano oils against two Gram-positive cocci, foods, this research investigated the antimicrobial activity of garlic, in Biology presented on using a growth inhibition test of the bacteria on cooked meat (Difco) and rat chow (Purina) broth. The MIe of garlic oil was 400 ppm. The pH and the composition of the media influenced the antimicrobial activity of the spice oils. The toxic effects of orally administrated garlic oil (400 ppm) was also evaluated on albino rats. After feeding the rats with garlic oil for one month, the rats lost 15% of their normal weight and no other visual toxic effects were observed. Garlic oil proved to be an effective natural antimicrobial agent against food-borne microorganisms, but requires further evaluations.