Are these food products fraudulent? Rapid and novel triplex-direct PCR assay for meat identification

Unintentional contamination and fraudulent labeling of food, especially in halal-certified products, breach both religious and international laws. DNA-based methods are widely employed to identify trace amount of contaminants for law enforcement. Direct PCR has proved successful in the DNA analysis from degraded samples and PCR-inhibited samples, but it has never been applied to meat identification from food products. In this study, we aimed to develop a multiplex direct PCR assay for simultaneous identification of three commonly consumed meats without the need to extract DNA. Species-specific primers were designed from the mitochondrial DNA using the alignment of sequences available on GenBank. The assay was validated for its specificity, sensitivity, and usefulness in market sample analysis. The results showed that a highly specific and sensitive multiplex direct PCR assay was developed and provided the expected PCR fragment of approximately 100, 119, and 133 bp for pork (Sus scrofa), mutton (Ovis aries), and chicken (Gallus gallus), respectively. Thirty-nine market samples were tested and a small number of fraudulent labeling was detected. In conclusion, we developed a rapid and inexpensive test for three meat species. This cost-and time-saving assay could be easily adopted in the world food hubs, which are mostly third-world countries. (C) 2013 Elsevier Ireland Ltd. All rights reserved.