LAUSR

The presence of <1% of an undeclared species in ground meat is generally thought to be indicative of cross-contamination as opposed to intentional mislabeling; however, this has not been experimentally tested. The objective of this study was to quantify the effects of poor sanitation on the cross-contamination of animal species in ground meat products, with the example of undeclared pork in ground beef. Cross-contamination was quantified using real-time polymerase chain reaction (PCR). Three different sanitation treatments were tested with a commercial grinder (“no cleaning”, “partial cleaning”, or “complete cleaning”) in between grinding of pork and beef samples (13.6 kg each). A 100-g sample was collected for each 0.91 kg (2 lb) of beef processed with the grinder and each sanitation treatment was tested twice. For the “no cleaning” treatment, the first 100-g sample of ground beef run through the grinder contained 24.42 ± 10.41% pork, while subsequent samples (n = 14) contained <0.2% pork. With “partial cleaning,” the first sample of ground beef contained 4.60 ± 0.3% pork and subsequent samples contained <0.2% pork. Pork was not detected in ground beef following “complete cleaning.” These results indicate that incomplete cleaning of grinding equipment leads to species cross-contamination at levels of <1% in most cases. Proper sanitation procedures must be followed when grinding multiple species in order to prevent cross-contamination and product mislabeling.