Microbiological profile and decontamination treatments for beef variety meats

Studies were conducted to determine microbiological profiles for beef variety meats and to evaluate decontamination techniques in removing bacterial contamination. Experiment 1 determined baseline microbiological information for 17 variety meats. Experiment 2 evaluated the effect of 13 microbiological decontamination techniques for their ability to reduce bacterial counts. Experiment 3 evaluated the bacteriological benefits of applying acetic or lactic acid to beef oxtail and tongue before vacuum packaged storage. Experiment 4 determined to what degree decontamination treatments could reduce the level of Escherichia coli O157:H7 and Listeria monocytogenes from inoculated samples of variety meats. Results from experiment 1 demonstrated that the microbiological counts of beef variety meats were highly variable, with weasand, rumen tripe, and cheek meat being the most variable. Pathogen incidence was relatively low, with 0.8% of samples positive for Salmonella spp. and 4.5% of samples positive for L. monocytogenes. In examination of 830 samples of beef variety meats, no samples were confirmed positive for E. coli O157:H7. When decontamination treatments were evaluated in experiment 2, use of organic acids, trisodium phosphate and hot-water (80°C) treatments generally resulted in variety meats that had lower bacterial counts following application of treatments, when compared with controls. In experiment 3, oxtail and tongue treated with acetic (2%) or lactic (2%) acid did not reach a total plate count of 6 log CFU/g until 56 days of storage under vacuum, while control samples reached the same level of counts by day 21. Use of acetic or lactic acid treatments lowered the initial level of lactic acid bacteria counts. However, by day 35 (for oxtail) and day 21 (for tongue) treatments were not different (P > 0.05) from the control in lactic or bacterial counts. In experiment 4, variety meats inoculated with L. monocytogenes had lower bacteria counts following application of acetic or lactic acid. Lactic acid generally provided the greatest reduction (as much as 4.6 log CFU/g) in the counts of variety meats inoculated with E. coli O157:H7. Results from these studies documented that decontamination treatments that have been efficacious for beef carcasses would also reduce bacterial counts on inoculated and uninoculated beef variety meats.