Microbiology of the swine head meat deboning process

The microbiology of swine head meat was evaluated by comparing the levels of aerobic plate count (APC), coliforms, and Escherichia coli as well as the incidence and levels of Salmonella spp. in swine head meat harvested by either the old or a new improved procedure. Based on 144 samples (72 by each procedure), the levels of APC, coliforms, and E. coli were 4.52 +/- 0.26, 2.37 +/ 0.42, and 2.25 +/ 0.42, and log(10) CFU/g respectively, regardless of the procedure used for harvesting the meat. The incidence (27/22) versus 28/72) and MPN levels (4 to 93 versus 4 to 1100) of Salmonella spp. determined by the Bacteriological Analytical Manual (BAM) methods also were the same for meat obtained using either the old or the new procedure. The BAM method detected a higher incidence of Salmonella spp. (55/144) than other methods, PCR(38/144; BAX, Du Pont) or DNA hybridization (41/144; Gene-Trak). Time of harvesting during the processing day or site of origin of the head meat (check versus tongue versus back of head) had no effect on the incidence of Salmonella spp. The data in this study indicate that the levels of bacteria encountered in swine head meat are a reflection of the harvesting procedures themselves, as well as levels in and around the head and oral cavity of swine.