HOT-FAT TRIMMING EFFECTS ON THE MICROBIOLOGICAL QUALITY OF BEEF CARCASSES AND SUBPRIMALS

Subcutaneous and kidney-pelvic-heart fat were trimmed from one side of each beef carcass (n = 9) immediately after cold water washing. Both sides were sampled for aerobic plate counts (APCs) before being moved to the chill room (0 h) and after 72 h of cold storage. The mean APCs log(10) colony-forming units (CFU)/cm(2)) of trimmed (HFW) sides at 0 or 72 h were not different (P>0.05) from those of the nontrimmed (NFT) sides. All sides at 72 h had reduced microbial counts compared to 0 h . By 72 h, HFT sides had numerically lower counts than NFT sides, indi cating that the microbial reduction effect of the chill temperature ma y have been greater on fat-trimmed carcasses than on nontrimmed carcas ses. Subprimals from HFT and NFT sides that were trimmed to 0.64-cm fa t thickness were microbiologically analyzed before (0 days) and after (14 days) vacuum storage. APCs of all subprimals were slightly reduced after 14 d; however, no difference (P>0.05) occurred in treatment eff ect. The mean APC was higher for HFT-side subprimals than for NFT-side subprimals at both 0 and 14 days. This difference probably was due to the fat trimming required for NFT-side subprimals at day 0 as compare d to minimal or no trimming of HFT-side subprimals. Those HFT subprima ls which were not subsequently trimmed may have picked up additional m icroorganisms from contact surfaces during fabrication. Based on our t rimming protocol, although HFT did not show any negative impact on the microbial quality of carcasses, the higher APC of HFT-side subprimals indicated that extensive trimming may not be effective in improving t he microbial quality of meat.