Comparative survival of Salmonella typhimurium DT 104, Listeria monocytogenes, and Escherichia coli O157:H7 in preservative-free apple cider and simulated gastric fluid

This study compared the survival of three-strain mixtures (ca. 10 7 CFU ml −1 each) of Salmonella typhimurium DT104, Listeria monocytogenes, and Escherichia coli O157:H7 in pasteurized and unpasteurized preservative-free apple cider (pH 3.3–3.5) during storage at 4 and 10°C for up to 21 days. S. typhimurium DT104 populations decreased by 7.0 log 10 CFU ml −1 decrease) after 14 days at 4°C in unpasteurized cider. In related experiments, when incubated in simulated gastric fluid (pH 1.5) at 37°C, S. typhimurium DT104 and L. monocytogenes were eliminated (5.5–6.0 log 10 CFU ml −1 decrease) within 5 and 30 min, respectively, whereas E. coli O157:H7 concentrations decreased only 1.60–2.80 log 10 CFU ml −1 within 2 h.