Antimicrobial effect of guava on Escherichia coli O157:H7 and Salmonella typhimurium in liquid medium

This study investigated the antimicrobial effects of guava against E. coli O157:H7 and Salmonella in liquid medium. The minimum inhibitory concentration (MIC) and the minimum lethal concentration (MLC) values for each bacterial strain were recorded. In addition, the growth of the individual strain and a combined mixture of the strains in liquid medium over time were assessed. Guava was found to inhibit the growth of all tested strains. The MIC ranged from 200 to 700 μL/mL and the MLC was at least 500 μL/mL. The minimum effective guava extract concentration needed to show significant growth inhibition was 5%. Without guava extract, bacterial population levels reached 7.0-8.0 log CFU/mL. The addition of guava extract caused significant growth inhibition, resulting in bacterial populations remaining within 3.0 log CFU/mL during the incubation. These results indicate guava could be used as a potential effective antimicrobial agent that can be used to ensure food safety. Copyright © Taylor & Francis Group, LLC.