Comparison of real-time PCR and ELISA-based methods for the detection of beef and pork in processed meat products

Two commonly used methodologies for species detection within processed meat products are real-time polymerase chain reaction (PCR), a DNA-based method, and enzyme-linked immunosorbent assay (ELISA), a protein-based method. In this study, a real-time PCR assay was compared to a commercial ELISA kit based on sensitivity, specificity, agreement among duplicate samples, cost, time, and ease of use. Fifteen reference samples containing known percentages (0.1-99.9%, w/w) of pork and beef were analyzed in duplicate using both methods. Thin}, commercial products, including sausages, pet treats, and canned meats, were also tested in duplicate with each method. Reference sample analysis showed real-time PCR was able to detect pork in duplicate samples at 0.10% and beef at 0.50% in the binary mixtures. ELISA detected pork in duplicate samples at 10.0% and beef at 1.00% in the binary mixtures. When the results of reference and commercial samples were combined, real-time PCR demonstrated the greatest agreement among duplicate samples, at 96.7%, compared to 95.6% agreement for ELISA. The real-time PCR assay used in this study was found to be less expensive, while ELISA was less time-consuming and easier to perform. Both methods were successful at identifying species in ground meats, sausage, and deli meat samples; however, pet treats and canned meats proved more challenging. Overall, it was determined that the real-time PCR assay was optimal for species identification in processed meat products when a low detection limit is required; however, the ELISA kit may be advantageous in other situations due to its ease of use. (C) 2016 Elsevier Ltd. All rights reserved.