USE OF HOT-WATER FOR BEEF CARCASS DECONTAMINATION

Hot water treatment of beef carcass surfaces for reduction of Escheric hia coli O157:H7, Salmonella typhimurium, and various indicator organi sms was studied using a model carcass spray cabinet. Paired hot carcas s surface regions with different external fat characteristics (inside round, outside round, brisket, flank, and clod) were removed from carc asses immediately after the slaughter and dressing process. All cuts w ere inoculated with bovine feces containing 10(6)/g each of rifampicin -resistant E. coli O157:H7 and S. typhimurium, or with uninoculated bo vine feces. Surfaces then were exposed to a carcass water wash or a wa ter wash followed by hot water spray (95 degrees C). Counts of rifampi cin-resistant Salmonella and E. coli or aerobic plate count (APC) and coliform counts were conducted before and after each treatment. All tr eatments significantly reduced levels of pathogens from the initial in oculation level of 5.0 log(10) CFU/cm(2). Treatments including hot wat er sprays provided mean reductions of initial counts for E. coli O157: H7 and S. typhimurium of 3.7 and 3.8 log, APC reductions of 2.9 log, a nd coliform and thermotolerant coliform count reductions of 3.3 log. T he efficacy of hot water treatments was affected by the carcass surfac e region, but not by delaying the treatment (30 min) after contaminati ng the surface. Verification of efficacy of hot water interventions us ed as critical control points in a hazard analysis critical control po int (HACCP) system may be possible using coliform counts.