Q01084/87/88/89/90: Final optimisation and evaluation of DNA based methods for the authentication and quantification of meat species.

Study Duration: September 2003 to March 2005

Contractor: Central Science Laboratory (CSL), RHM Technology, Veterinary Laboratory Agency, Eurofins, Campden and Chorleywood Food Research Association (CCFRA)

The Food Labelling Regulations 1996 require a Quantitative Ingredient Declaration (QUID) for all ingredients mentioned in the name of the food. Therefore, products specifying a type of meat in the name of the food have to stipulate the amount of that meat in the product. A validated method to detect and quantify meat content in meat products was therefore required to assist in enforcement of this legislation.

This collaborative project aimed to optimise and evaluate DNA methods developed from previously funded FSA projects based on real-time polymerase chain reaction (RT-PCR) for meat species identification and measurement.

The first phase of the project focused on optimisation and evaluation of different in-house methods routinely used by the five collaborating laboratories. The most appropriate DNA extraction technique for a variety of meat matrices was determined and RT-PCR assays for meat speciation were compared in a proficiency trial using complex meat product samples.

The second phase of the work investigated the ability of two different species-specific quantitative PCR assays to determine the amount of meat in a commercial sample.

The most appropriate method for standard curve construction and quantitative analysis was determined by comparison of standard curves produced using a range of samples containing a known quantity of meat.

A qualitative species-specific RT-PCR assay was optimised in the initial portion of this project. A single DNA extraction technique was found to be suitable for all meat matrices tested. The proficiency test of the RT-PCR assays used by the collaborating laboratories showed that all the assays were able to correctly identify the species present within the samples. Based on these studies, a comprehensive set of standard operating procedures (SOPs) for the identification of meat species in complex foods using RT-PCR were developed.

Several different methods for the quantification of meat species in a mixed sample were examined, however none of the calibrated methods proved robust enough to be considered suitable for reliable meat content quantification.