The effects of hot water pasteurizing treatments on the microbiological conditions and appearances of pig and sheep carcasses

Twenty-five pig carcass sides and 25 unsplit pig carcasses were treated with water of 85 degrees C for 10 s in a commercial apparatus for pasteurizing carcasses. The treatment reduced the log total numbers of total aerobic counts, coliforms and Escherichia coli recovered from sets of 25 random samples, each sample being of a 100 cm(2) area of carcass surface, by > 1, > 2 and > 2 log units, respectively. After sides had been cooled for about 20 h, the appearances of cut muscle surfaces which were exposed to the treatment were assessed by a 5-member panel as substantially less desirable than untreated cut muscle surfaces. The overall appearances of treated sides were similarly assessed as undesirable in comparison with the appearances of untreated sides. However, the small areas of affected cut muscle on sides from pig carcasses which were treated before they were split had little effect on assessments of their overall appearances. An experimental pasteurizing treatment of sheep carcasses was similarly assessed as having substantial, deleterious effects on the appearances of cut muscle surfaces, but little effect upon the overall appearances of carcasses. The findings indicate that pasteurization of eviscerated pig carcasses before splitting, or pasteurization of skinned and eviscerated sheep carcasses in conjunction with a decontaminating cooling process would allow the production of sides or carcasses from which E. call would be recoverable at log total numbers about 0/2500 cm(2) without unacceptable degradation of the appearances of the products. (C) 1999 Canadian Institute of Food Science and Technology. Published by Elsevier Science Ltd. All rights reserved.