Purpose: The objective of this study was to test the efficacy of natural, cost-effective, and efficient intervention methods to decontaminate fresh leafy greens from foodborne pathogens (Salmonella and E. coli).
Methods: The efficacy of lemon juice, lime juice, and vinegars at 5% acetic acid (white, apple cider and red wine) was tested against ~107 log CFU/ml Salmonella and E. coli cocktails at 0, 30, and 60 min in vitro. Following this, the most effective intervention (at various concentrations) was applied on fresh lettuce inoculated with ~ 105 CFU/g Salmonella and E. coli cocktail for a contact time of 15 min. The microorganisms were plated on Eosin Methylene Blue media (EMB) to differentiate between E. coli and Salmonella colonies.
Results: The results of the in vitro studies demonstrated that white vinegar was the most effective intervention against both microorganisms causing a reduction of 103 CFU/ml at 30 min and counts below detection limit at 60 min. White vinegar was applied at concentrations 1.25%, 2.5%, and 5% acetic acid on lettuce inoculated with ~ 105 CFU/g Salmonella and E. coli. The results demonstrated that the application of 2.5% and 5% white vinegar were the most effective at reducing E. coli and Salmonella by 102 and 103 CFU/g respectively.
Significance: The application of a natural antimicrobial agent such as white vinegar (1:1 dilution) on fresh produce significantly reduces the risk of foodborne pathogens such as Salmonella and E. coli. This intervention could keep the consumer safe and free from foodborne disease.