Meat from wild boar is considered to be a premium product due to its characteristic flavour. Wild boar meat therefore fetches a significant price premium and subsequently there is the potential for substitution of wild boar meat with meat from domestic pigs. Food labelling regulations require that the species of meat in a meat product is accurately labelled. A robust method to identify wild boar meat and differentiate it from pig meat is therefore required to enable the verification of both whole meat cuts and meat products labelled as wild boar. Such a method would also complete a suite of exotic and common meat verification tests whose development was funded by the Agency.
Research Approach:<BR> Assays to distinguish between species are often based on differences in the DNA sequence of the target species. Wild boar and domestic pig breeds are subspecies that can only be distinguished from one another at the DNA level using highly discriminating techniques. This project assessed the suitability of two such techniques that are based on identifying DNA markers, microsatellite analysis and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis, for the discrimination of meat from wild boar and pig breeds. This involved sourcing samples from authentic wild boar and traditional and rare pig breeds, and identifying a minimum set of microsatellite markers (simple satellite repeats, (SSRs)), and/or PCR-RFLP markers that can differentiate between the DNA from wild boar and pig breeds. Commercial samples containing wild boar and pig in varying amounts were simulated by combining DNA from wild boar and different pig breeds. The set of markers was then used to develop a method to distinguish meat from wild boar and breeds of pig.
Results and Findings:<BR> PCR-RFLP analysis was shown to be capable of discriminating pure wild boar meat from pure pig meat but is not suitable for the analysis of more complex samples, such as meat from cross breeds, and mixtures of wild boar meat and pig meat. However, using microsatellite analysis, a panel of 8 microsatellite markers was identified that could distinguish pure wild boar meat from pure breed or cross-breed pig meat, and a panel of 21 microsatellites was capable of identifying mixtures containing 50% or greater wild boar DNA mixed with pig DNA as wild boar-pig mixtures. The method using these microsatellite markers was optimised, resulting in a standard operating procedure (SOP) for the verification of meat from wild boar, which is suitable for the analysis of cuts of meat. The SOP was internally validated, and was shown to correctly assign unknown samples of meat cuts as either wild boar or pig.
<p>Find more about this project and other FSA food safety-related projects at the <a href="http://www.food.gov.uk/science/research/" target="_blank">Food Standards Agency Research webpage</a>.