Microbial Decontamination of Beef and Sheep Carcasses by Steam, Hot Water Spray Washes, and a Steam-Vacuum Sanitizer.

Research paper by Warren J WJ Dorsa, Catherine N CN Cutter, Gregory R GR Siragusa, Mohammad M Koohmaraie

Indexed on: 28 Jan '20Published on: 01 Feb '96Published in: Journal of food protection


Three separate studies were conducted to determine the effectiveness of various temperature water spray washes (W), wash and steam combinations (WS), and vacuum and wash combinations (VW) for reducing fecal bacteria on sheep and beef carcasses. W of 15.6, 54.4, and 82.2°C were administered to sheep carcasses contaminated with feces, using a hand-held spray nozzle. Initial carcass bacterial populations of approximately 2.5, 4, and 6 log CFU/cm were subjected to all wash combinations. W and WS reduced 6 log CFU/cm bacterial populations as much as 4.0 log cycles. When carcasses were subjected to WS and W, the initial contamination levels (4 and 6 log CFU/cm) had little effect on final bacterial levels (2.7 to 3.3 log CFU/cm). However, uninoculated carcasses with initial bacterial populations of 2.5 log CFU/cm experienced a 1.5-log-cycle reduction when subjected to WS and W. It is possible that hydration of a carcass before and during interventions affords some protection to bacteria. The next study used a commercial carcass washer to apply a hot water (72°C), low pressure (20 psi) wash in combination with a high pressure (125 psi), warm water (30°C) wash (W). Reductions on beef of 2.7, 3.3, and 3.4 log cycles for aerobic plate count (APC), coliforms, and E. coli populations, respectively, were observed. When a commercial steam-vacuum was used in conjunction with W, reductions of 3.1, 4.2, and 4.3 log cycles for APC, coliforms, and E. coli populations, respectively, were achieved. Implementation of these interventions could reduce the amount of trimming needed on carcass-processing lines and would increase the microbial safety of beef carcasses.