The Antimicrobial Effect of Garlic Extract on Staphylococous aureus and Escherichia coli O157:H7 in Ready to Cook Chicken

In recent years chemical preservatives have been commonly used in foods to increase the shelf life. Due to these preservatives their continuous use in food might not be recommended therefore the application of natural preservatives, substances that have been employed for a long period is preferred. In this research, the antimicrobial effects of garlic extract, a natural preservative has been investigated in ready to cook chicken. The minimum inhibitory concentrations of the garlic extract were determined by using agar dilution method for Staphylococousaureus and Escherichia coli O157:H7in vitro. Furthermore for testing the antimicrobial effect of garlic extract in food system, different concentrations of garlic extract (0, 6, 7, 8, 10 mg/ml) were added to ready to cook chicken and the activities were evaluated after 24, 48, 72 hours and one week. The effects of adding different concentrations of extract on sensory behaviour were also evaluated. The results have shown that Garlic extract has significant anti-microbial effects on the tested bacteria and the MIC was 7 mg/ml for both bacteria. By increasing the concentration of the garlic extract, the counts were reduced (p<0.05). It is also proved that the optimum concentrations (7, 8 mg/ml) of garlic extract had a significant effect on the sensory characteristics of cooked chicken. The optimum concentration of garlic extract, apart from decreasing the bacterial counts and increasing the shelf life, had a positive effect on organoleptic properties of cooked chicken. Therefore this compound might be employed as replacement for the chemical preservatives used in food industry.