Synergistic effect of carvacrol and ohmic heating for inactivation of E. coli O157:H7, S. Typhimurium, L. monocytogenes, and MS-2 bacteriophage in salsa

Abstract

Foodborne outbreaks have still been reported worldwide, and acid resistant foodborne pathogens are biological hazards in salsa. We investigated the combination effect of carvacrol and ohmic heating for inactivation of foodborne pathogens in salsa. Salsa samples were subjected to carvacrol, ohmic heating, and the combination treatment to identify any synergistic effect. Quality aspects of salsa such as color and lycopene content were also observed after each treatment. The synergistic bactericidal effect of combination treatment was observed for Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes. A synergistic virucidal effect of combination treatment was also observed for MS-2 bacteriophage, which is a surrogate for human norovirus. Moreover, L* and a* values were improved by combination treatment compared to ohmic heating. Therefore, the combination treatment of carvacrol and ohmic heating could be used effectively to process salsa without incurring quality degradation.