Detection of Listeria monocytogenes, Escherichia coli and Salmonella species in Ready-to-eat Salad by Rapid Microbiological Detection Methods (Redox potential measurement + Real-time PCR)

Abstract

With the increase in awareness of people consuming a healthy nutritious diet, vegetables are a great way to add vitamins, minerals and dietary fibre to our everyday food regimen. Which has led to an increase in the demand of these Ready-to-Eat salads. Since these food products are eaten raw and are minimally processed there is an increased risk for pathogenic contamination. To provide a safe product for consumers and minimize the risk of people getting contaminated with pathogens from eating these products. The detection of bacteria before sending edible products to the shelves in markets are a must. Conventional culture methods have been the choice for pathogen detection for a long time but unfortunately, they are time consuming and labour intensive, taking almost an average of 5 days to get results, which puts food producers at a disadvantage when their food products have a short shelf life. Therefore, in this study we have used redox potential based measurement in combination with real-time PCR for the detection of three different potentially harmful pathogens to human health. We used Salmonella typhimurium, Listeria monocytogenes and Escherichia coli as the pathogens in Ready-to-Eat salad obtained from local supermarkets. All the samples were also examined by the conventional culture methods as a comparison.