Market Analysis of Food and Feed Products for Detection of Horse DNA by a TaqMan Real-Time PCR

Abstract

Food-labelling regulations require that meat species in food and feed are accurately declared to the consumer. Traceability systems based on species identification through DNA analysis are potent tools for the supervision of food adulteration. In this study, a TaqMan real-time polymerase chain reaction (PCR) assay targeting a short mitochondrial 12S ribosomal RNA (rRNA) gene fragment of 73 base pair (bp) was developed for detection of horse DNA in different commercial meat products for human and pet consumption. The method was found to be specific for horse and did not show any cross-reactivity with different species of mammals, birds, fish and plants. The assay complies with the acceptance criteria required for real-time PCR methods in terms of applicability, linear dynamic range, accuracy and PCR efficiency and showed to be sensitive allowing the detection of 1 pg of horse DNA. A range of food and feed products (n = 171) was screened with the horse-specific real-time PCR to determine whether a correct labelling had been employed at the market level. Results obtained when testing the meat products for human consumption were in agreement with the labelling description provided by the suppliers. In the case of the pet foods, undeclared horse meat was detected in 21 % of the samples at low levels, suggesting unintentional cross-contamination during processing. The reported real-time PCR methodology may represent a suitable tool for the detection of food mislabelling.