Growth Inhibition of Food-borne Bacteria by Juice and Extract of Ginger and Garlic

생강과 마늘 즙 및 추출물의 식중독 세균에 대한 증식저해작용

This study was conducted to understand the inhibitory garlic and ginger against the growth of food born pathogenic bacteria. Juice was prepared from the raw spices by using an electric homogenizer and membrane filter. Dry-powdered spices were treated with double distilled water and 70% ethanol to extract the antibacterial substances, respectively. Growth inhibitory effects of juice and extracts of the spices were monitored by using bacterial strains such as B. subtilis, L. moncytogenes, S. aureus,E. coli O157 : H7, P. aeruginosa, and S. typhimurium. On a solid medium where E. coli and S. aureus cells were grown, ginger juice formed inhibitory zone at the concentrations of 2-10% by paper disc test. The Bone formed by ginger juice was wider and more transparent than that formed by garlic juice on the same concentration.1. monocytogenes and B. subtilis were more sensitive to garlic juice than others, and stopped growing at 2% garlic juice. Ginger juice showed the growth inhibition by 30-50% at 1.0% concentration. On the contrast, P. aeruginosa which resisted to the garlic juice was the most sensitive to ginger juice. Water extract of garlic was not effective to inhibit the bacterial growth, while 2% ginger extract completely inhibited the growth of E. coli and S. aureus. Alcohol extract of ginger inhibited the growth of bacteria at the concentration of 0.3%. This growth inhibition is almost 10 times lower than that of the garlic extract. It was clear that ginger had more potential than garlic as an inhibitor to control the growth of the indicator organisms.