Evaluating the antimicrobial effects of turmeric, ginger and clove extracts on some food pathogen

Abstract

The aim of this study was to investigate the antibacterial effects of hydroalcoholic extracts of turmeric, ginger and clove on food pathogens including Salmonella Typhimurium, Shigella Dysenteriae and E. coli. To determine the antimicrobial effects, certain volumes of hydroalcoholic extracts of turmeric, ginger and clove were added to the blank disks, and after culturing the bacteria in Müller-Hinton Agar culture medium, the disks were placed on the culture medium and after the time required for the growth of the microorganism, the cultures were examined for the diameter of the growth inhibition zone. Among the aqueous extracts, the highest antibacterial effect was related to the aqueous extract of turmeric on Escherichia coli pathogen with an average diameter of the growth inhibition zone of 17 mm and the lowest antibacterial effect was related to the aqueous extract of turmeric versus Salmonella with an average diameter of the growth inhibition zone of 9.5 mm. Among ethanolic extracts, the highest antibacterial effect was related to turmeric and ginger against Escherichia coli and Shigella (average diameter of growth inhibition zone 15.1 mm) and the lowest effect was related to ethanolic extract of turmeric versus Salmonella (mean diameter of growth inhibition zone of 10 mm. Among methanolic extracts, the highest antibacterial effect was related to turmeric methanolic extract versus Shigella (mean diameter of growth inhibition zone of 16.8 mm) and the lowest effect was related to methanolic extract of clove versus Escherichia coli (mean diameter of growth inhibition zone of 10.5 mm). Among the studied pathogens, Salmonella showed the highest sensitivity to the hydroalcoholic extracts of the medicinal plants used, and the highest resistance was obtained for Shigella. Considering that the hydroalcoholic extracts of turmeric, ginger and clove have antimicrobial properties, they can be used as food preservatives against Salmonella, Escherichia and Shigella.