Species substitution in goat yoghurt supply chain using melting-curve analysis

Mislabelling of dairy products has been widely reported worldwide but there are relatively few data available to help assess species substitution in goat yogurt. The purpose of this study was to investigate the presence of bovine and sheep milk in yogurt labeled as being made exclusively from goat milk, using qualitative real-time PCR. The results confirm that fermented products are targets for food species substitution, highlighting the undeclared presence of cow and/or sheep milk in 39.6% of samples analysed. Moreover, the study shows that the qualitative real-time PCR used here is a rapid, sensitive (LODabs of 0.015 ng/mu L), specific (no primer-dimers or non-specific products in the reactions), straightforward and low-cost molecular tool for discriminating adulterants in the dairy supply chain. Therefore, melt-curve analysis is a promising tool for facilitating routine safety, quality and authenticity checks in the dairy industry, and for implementing mitigation strategies against fraudulent activities. Application of DNA-based approaches is crucial for designing an innovative food safety management system and for helping to implement both a Food Fraud Vulnerability Assessment and a Food Fraud Prevention Strategy as common practices in the dairy sector.