INACTIVATION OF PATHOGENIC BACTERIA BY FD&C RED NO. 3 AND HIGH-PRESSURE PROCESSING COMBINATION TREATMENT IN FOOD SYSTEMS

Combinations of FD&C Red no. 3 and high-pressure processing (HPP) effectively inactivate various important processing-resistant spoilage and pathogenic bacteria in buffer; however, the lethality is unverified in food. The objective of this study was to determine the efficacy of HPP-Red 3 to inactivate Listeria monocytogenes and Escherichia coli O157:H7 in two food systems. Sterile carrot juice and turkey product were inoculated with stationary-phase cells and treated with HPP-Red 3. Red 3 concentrations of 10-100 ppm in carrot juice with HPP (500 MPa, 1 min, 23C) produced synergistic inactivation of L. monocytogenes. HPP-Red 3 (100 ppm) combinations in carrot juice caused synergistic inactivation of E. coli. HPP was ineffective at reducing L. monocytogenes in pre-cooked luncheon turkey product. HPP reduced E. coli in turkey product (3.9 log reduction); however, combination treatment did not significantly increase lethality, regardless of Red 3 concentration. Food systems significantly impact the efficacy of HPP-Red 3 against foodborne pathogens.