Sausage mislabelling in Canada is down, DNA testing reveals, although 14 percent of tested products still found meat species not indicated on the label.
The mislabelling of sausages, selected from grocery stores across the country, was down from a first-ever study conducted by the same researchers just over a year ago that revealed a 20-per-cent mislabelling rate.
“We have reassessed the rates of mislabelling and found lower levels,” said Professor Robert Hanner, of the University of Guelph, who led the study.
“The Canadian Food Inspection Agency (CFIA) took follow-up action after our initial study, and it appears that it had an impact.”
Researchers tested sausages labelled as beef, chicken, pork or turkey. They also tested the samples for sheep, goat and horse.
Unlike the previous study that uncovered horse meat in one pork sausage sample, researchers found no horse meat this time.
The research, the findings of which have been published in the journal Food Research International, focused on sausage packs labelled as containing only one type of meat.
The researchers used DNA barcoding along with digital PCR technology to determine which meats were in the sausage samples.
“There is DNA in nearly every cell of every organism, so barcoding can be applied to products such as ground meats that would be difficult to identify with other means,” said Hanner, integrative biology professor in the university’s Biodiversity Institute of Ontario.
“We decided to also include sheep and goat in this most recent study because although they may not be consumed in the same quantities as beef, chicken, pork and turkey, they are commercially raised meats that are commonly present in our food supply chain,” Hanner said.
Products were considered contaminated when more than 1 per cent of another meat was detected. This ruled out trace amounts that might have resulted from incomplete cleaning of processing equipment.
Of the 30 beef sausages tested, five contained sheep, four contained pork and one contained chicken.
Among the 20 chicken sausages tested, three contained turkey, one contained pork and one beef. Of the turkey sausages tested, one contained chicken and one contained pork. All the pork sausages samples had only pork, meaning no cross-species contamination.
Sausages labelled as single-meat but containing more than one meat type contravene food labelling regulations. Consumers may buy these products because of health issues, such as allergies, or lifestyle choices, such as avoiding pork, Hanner said.
Unknown contaminants may also allow transfer of food pathogens, he added.
“In certain cases, it may be of concern when there is a recall on a specific type of meat, but it is not indicated on the label.”
He said it is difficult to determine whether cross-species contamination was economically motivated.
“We don’t know the exact cuts of meat that were found in the samples, so we can’t determine if the contaminant meat was purposely substituted because it was a cheaper meat.”
The next step would be to test throughout the supply chain to determine where mislabelling and cross-species contamination happens.
“We are looking at it from the retail market and finding that there are issues,” Hanner said. “But in order to get a full understanding, we need to look at it from multiple points within the food chain.”
The CFIA’s deputy chief food safety officer, Dr Aline Dimitri, said scientific innovation helped protect Canada’s food supply on many levels, and DNA barcoding played an important role through species identification.