Critical points in meat production lines regarding the introduction of Listeria monocytogenes

In order to elucidate critical points concerning Listeria monocytogenes during bovine and porcine slaughter, cutting and processing, 843 samples were obtained from carcasses, primal cuts, products at retail and from environmental surfaces. Only 2-7% of the carcasses and 0-10% of the environmental samples in the 'clean' part of the pork slaughterline were found to be positive for L. monocytogenes. The incidence of L. monocytogenes was increased after chilling and cutting. In the cutting room 11-36% of the primal cuts and 71-100% of the environmental samples were found positive for L. monocytogenes. Our findings indicate that contamination of pork meat with L. monocytogenes originates from the processing environment of the chilling or cutting room. The incidence of L. monocytogenes in the bovine cutting and meat processing line (0-60%) was lower than in the porcine cutting and meat processing line (11-100%).