GUELPH, Ontario – A government-funded study of methods to detect “undeclared species” in retail sausage products is raising eyebrows, and possibly turning stomachs, in Canada.

Researchers with the Univ. of Guelph used DNA barcoding to determine the predominant species, and digital PCR technology was used to detect and quantify contaminant meat species in a sample of 100 raw meat sausage samples that were labeled as containing beef, pork, chicken or turkey. Additionally, researchers tested all the samples for horse meat. Sausage products were considered contaminated with more than 1 percent of a contaminant species.

“All samples contained the predominant species matching the label species except for five turkey sausage samples which contained chicken as the predominant species,” according to the study abstract.

The tests also revealed that 6 percent of beef sausage also contained pork; 20 percent of chicken sausage contained turkey while 5 percent contained beef; and 5 percent of pork sausages also contained beef. “Five samples labeled as turkey sausage contained no turkey and one pork sample was found to contain horse meat,” the study said. “The overall mislabeling rate detected in this study was 20 percent and the results provide a baseline for assessing species mislabeling in processed meat products in Canada.”

The researchers noted that complete or partial substitution of ingredients bears the risk of introducing foodborne pathogens or allergens into the food supply in addition to impacting personal or religious beliefs.

The study, titled “Complementary molecular methods detect undeclared species in sausage products at retail markets in Canada,” was published in the journal Food Control.