Antibacterial Effect of Garlic Aqueous Extract on Staphylococcus aureus in Hamburger

BACKGROUND: Using garlic is widespread in Iran and other countries as a medicine and a natural spice. Garlic is a potential inhibitor for food pathogens. Foods contaminated with pathogens pose a potential danger to the consumer’s health. The use of garlic can increase the shelf life and decrease the possibilities of food poisoning and spoilage in processed foods. OBJECTIVES: The aim of this study was to investigate the antibacterial effect of garlic aqueous extract on growth of Staphylococcus aureus bacteria. MATERIALS AND METHODS: In this study, the garlic aqueous extract was prepared under sterile conditions and was added in 1, 2, and 3 mL to 100g hamburger samples. A group of samples was prepared to be used as treatment sample, while a group was stored at 4°C and -18°C. The samples were kept in refrigerator for one and two weeks and they were frozen for one, two and three months and then subjected to microbial tests. RESULTS: Statistical evaluation of the first and second week samples indicated a significant growth decreased by all the 1, 2, and 3-mL extracts. In treatment of one, two and three-month samples, the growth of S. aureus was significantly decreased by the 2 and 3-mL extracts. The 1-mL extract was effective in decreasing the growth, and a significant difference was observed in treatments with 2 and 3-mL extracts. However, there was no significant difference between the two and three-month samples, though they were significantly different from the one-month samples. After evaluations, treatment with the 2-mL extract was found to be the best one. CONCLUSIONS: Garlic aqueous extract has antibacterial properties against S. aureus present in hamburger. Moreover, garlic aqueous extract can be used not only as a flavor but also as a natural additive for hamburger. In addition, garlic has antibacterial properties against other Gram-positive and Gram-negative bacteria, which must be investigated in further studies.