EVALUATION OF HAND-TRIMMING, VARIOUS SANITIZING AGENTS, AND HOT-WATER SPRAY-WASHING AS DECONTAMINATION INTERVENTIONS FOR BEEF BRISKET ADIPOSE-TISSUE

Various chemical solutions (5% hydrogen peroxide, 0.5% ozone, 12% trisodium phosphate, 2% acetic acid, and 0.3% commercial sanitizer), water (16 to 74 degrees C) spray-washing interventions, and hand-trimming/spray-washing treatments were compared for their ability to remove fecal material and to reduce bacterial contamination on beef brisket fat samples in a model spray-washing cabinet. The samples were inoculated with 2.5 cm(2) of a bovine fecal paste inoculated with Escherichia coli (ATCC 11370). Hand-trimming followed by spray-washing with plain water (16 to 74 degrees C when it came in contact with the sample; 20.68 bar pressure; for 36 or 12 s corresponding to chain speeds of 100 or 300 carcasses per h) lowered (P < 0.05) microbiological counts, compared to the inoculated control, by 1.41 to 2.50 log colony-forming units (CFU)/cm(2). Additionally, spraying with chemical solutions (16 degrees C; 1:38 bar, 12 or 36 s), before or after spray-washing with plain water (20.68 bar) of 16 degrees C (36 s), 35 degrees C (12 s) or 74 degrees C (12 s) reduced bacterial counts by 1.34 to 2.87, 1.18 to 2.86, or 0.96 to 3.42 log CFU/cm(2), respectively. Reduction in counts was influenced by water temperature (16 to 74 degrees C), type of chemical solution, and sequence of spray application. Under the conditions of this study, hydrogen peroxide and ozonated water were more effective (P < 0.05) than trisodium phosphate, acetic acid, and a commercial sanitizer when applied after first washing with plain water. Trisodium phosphate maintained its activity when used before washing with water. In general, water of 74 degrees C caused reductions (P < 0.05) exceeding 3.0 log CFU/cm(2), which were higher than those achieved by trimming and spray-washing. No spreading of bacteria in areas immediately adjacent to the inoculation site was detected following spray-washing.