Antibacterial Action of Garlic Extract on Food Poisoning Bacteria

We found that garlic extract had a strong growth-inhibitory activity toward various food poisoning bacteria. Aqueous extract of garlic (Allium sativum L.) was tested by an agar plate diffusion method for growth-inhibitory activity against 15 gram-negative and 8 gram-positive species. Our experimental results showed that the extracts had a bacteriostatic activity at low concentration (0.62-1.25%) regardless of the bacterial species used.The antibacterial activity of garlic extract was completely destroyed by heating at 100°C for 20 minutes, but was unaffected at 55°C for 20 minutes.The effect of pH of the extract on its bacteriostatic activity was also examined. The activity was stable at pH 6.0-7.0, but it decreased at pH 5.0 and also above pH 8.0.