Effect of Glycerol Monolaurate and Sodium Benzoate at Different Concentrations, Temperatures and pH on the Growth of Listeria Monocytogenes

Abstract

ABSTRACTGlycerol monolaurate and sodium benzoate are used as antimicrobial agents in variety of food. In our study; the effect of glycerol monolaurate and sodium benzoate at different concentrations, temperatures and pH on the growth of Listeria monocytogenes was investigated. During the experiments, Listeria monocytogenes strain 1/2a was used. Triptych soy broth was adjusted to pH 5.0, 5.6, 7.0, and supplemented with 5, 6, 7, 8, 9 mg/ml glycerol monolaurate. Sodium benzoate were added to the broth in rates of 0,5, 1, 1,5, 2, 2.5, 3 mg/ml and then approximately 103 cfu/ml L. monocytogenes was inoculated all broth and incubated at 7, 14, 21, and 35°C. Cultures were measured with spectrophotometer at appropriate time intervals to determine the growth inhibitory effect of all tested conditions. The growth inhibitory effect of different concentrations of glycerol monolaurate and sodium benzoate were determined by calculating generation times.L. monocytogenes was growth in sodium benzoate and glycerol monolaurate free broth controls under all conditions. At 7°C pH 5.6 and pH 5.0, growth of L. monocytogenes was inactivated in the presence of all concentrations of sodium benzoate and glycerol monolaurate. Results indicated that temperature and pH are most important factors influencing the efficiency of sodium benzoate and glycerol monolaurate on growth of L. monocytogenes. Thus, generation time of the organism influenced by temperature, pH, concentrations of sodium benzoate and glycerol monolaurate or their combined interactions.