Contribution of the main contaminating materials during pig slaughter to the microbial numbers on carcasses

During pig slaughter, contaminants such as intestinal and stomach contents, bile, tubular rail fat, and reddish foam from the respiratory tract frequently appear on carcasses, potentially compromising meat safety. This study examined the impact of these contaminants on the bacterial loads of pig carcasses, using total bacterial counts and Enterobacteriaceae counts as hygiene indicators. Examination of the substances as such showed that intestinal and stomach contents were particularly conspicuous to undermine the carcase hygiene due to total bacterial counts of ∼6.0 log10 CFU g-1 (intestinal content) and 5.5 log10 CFU g-1 (stomach content). Tubular rail fat showed varying contamination levels, from low (3.1 log10 CFU g-1) to high (6.4 log10 CFU g-1). The reddish foam had moderate contamination (4.3 log10 CFU g-1). Enterobacteriaceae levels mirrored these results at a lower level. Subsequently, a comparative study analysing bacterial levels in contaminated and in noncontaminated pork rind regions was performed. Even small amounts of intestinal and stomach contents led to significant increases in total bacterial counts of up to 3 log10 CFU cm-² and in Enterobacteriaceae counts (up to 5 log10 CFU cm-²). Other contaminants did not significantly raise bacterial levels: their total viable counts around 3.5 log10 CFU cm-² were similar to those of uncontaminated carcass areas. Nevertheless, they should be removed before further processing.