Bactericidal effect of plant extracts on pathogens in green leafy vegetables

According to the US Food and Drug Administration (FDA), in March 2013, the US FDA website introduced a study on the treatment of pathogenic bacteria in green leafy vegetables using plant extracts as fungicides In this study, 41 plant extracts, such as oregano and lime, were selected to study their sterilization effects on Salmonella, Escherichia coli O157 and Shigella in coriander, parsley and spinach In the process of the experiment, the test plants were extracted with ethanol, the minimum bactericidal concentration of the extract was determined, and the extract with the strongest bactericidal effect was selected for further study The leaves of fresh vegetables were washed with sterile water and dried, then immersed in two different concentrations of pathogenic bacteria suspension for inoculation, then dried and stored at 4 ℃ for standby The inoculated green leafy vegetables were immersed in chlorine, thiourea fungicide and plant extract solution respectively and stored at 4 ℃ for 0, 1, 5, 7 days to test the germicidal efficacy It was found that the germicidal intensity of Origanum officinalis leaf extract and lemon peel and pulp extract was similar to that of chlorine or thiourea bactericide, which could reduce the content of pathogenic bacteria in vegetables, so it could be used as a natural edible bactericide to reduce the risk of pathogenic bacteria pollution.