Inactivation of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella in cranberry, lemon, and lime juice concentrates

Abstract

The production of thermally concentrated fruit juices uses temperatures high enough to achieve at least a 5-log reduction of pathogenic bacteria that can occur in raw juice. However, the transportation and storage of concentrates at low temperatures prior to final packaging is a common practice in the juice industry and introduces a potential risk for postconcentration contamination with pathogenic bacteria. The present study was undertaken to evaluate the likelihood of Escherichia coli O157: H7, Listeria monocytogenes and Salmonella surviving in cranberry, lemon, and lime juice concentrates at or above temperatures commonly used for transportation or storage of these concentrates. This study demonstrates that cranberry, lemon, and lime juice concentrates possess intrinsic antimicrobial properties that will eliminate these bacterial pathogens in the event of postconcentration recontamination. Bacterial inactivation was demonstrated under all conditions; at least 5-log Salmonella inactivation was consistently demonstrated at -23°C (-10°F), at least 5-log E. coli O157:H7 inactivation was consistently demonstrated at -11°C (12°F), and at least 5-log L. monocytogenes inactivation was consistently demonstrated at 0°C (32°F).