STEAM VACUUMING AS A PREEVISCERATION INTERVENTION TO DECONTAMINATE BEEF CARCASSES

One steam-vacuuming unit (Unit A) was evaluated for removal of visible contamination and reduction of bacterial counts on beef carcass surfa ces in five processing plants; a second steam-vacuuming unit (Unit B) was evaluated in two of those same plants at a later date. Experimenta l treatments included appropriate controls: steam vacuuming carcass su rfaces with or without visible contamination, and knife trimming surfa ces with visible contamination. Depending on the processing plant, car casses were tested on the midline or on the round. Each treatment was applied to a 103-cm(2) area of the carcass surface, which was scored f or visible contamination and analyzed for aerobic plate counts (APC) a t 25 degrees C and for total coliform counts (TCC). Average reductions in APC of 0.57 (Unit A) and 0.72 (Unit B) log CFU/cm(2) and in TCC of 0.33 (Unit A) and 0.26 (Unit B) log CFU/cm(2) were obtained by steam- vacuuming carcass surfaces which had no visible fecal contamination. S team vacuuming and knife trimming effectively (P <0.05) cleaned soiled carcass surfaces and reduced microbial counts, Knife trimming reduced APC and TCC by 1.38 and 1.61 log CFU/cm(2) in the Unit A experiment a nd by 1.64 and 1.72 log CFU/cm(2) in the Unit B experiment, respective ly. Steam vacuuming carcass surfaces soiled with visible contamination reduced APC and TCC by 1.73 and 1.67 log CFU/cm(2) (Unit-A) and by 2. 03 and 2.13 log CFU/cm(2) (Unit B), respectively. The results of this study suggest that both steam-vacuuming systems available at the time of the study were at least as effective as knife trimming in decontami nating beef carcasses with areas of visible contamination 2.54 cm in t he greatest dimension.