A Method for Authentication of Meat by PCR Amplification of Species-specific Markers of Mitochondrial Origin

Abstract

Background: Adulteration of meat with their cheaper or inferior counterparts has become a common practice in the meat industry which threatens the feelings as well as the health of the people. Meat adulteration has issues relating to social, religious, economic, and public health. Therefore, it is important to develop simple and reliable techniques for the authentication of species of meat. Mitochondrial markers have been widely used in species identification and authentication as PCR of species-specific markers of mitochondrial origin is relatively rapid, accurate, sensitive and cost-effective as compared to other PCR based assays. The present study was carried out for authentication of raw and cooked meat from different species using PCR amplification of species-specific Cytb and D-loop markers of mitochondrial origin.Methods: In this study, detection of different raw meat viz. beef, carabeef, mutton, chevon, chicken, duck meat and dog meat as well as meat samples subjected to different processing temperatures was done using PCR of species-specific mitochondrial Cytb and D-loop markers. Samples of beef, carabeef, mutton, chevon, chicken, duck meat and dog meat were collected randomly from different locations of the North-Eastern region of India. The meat samples were subjected to heat treatment in hot water (80oC) to have 75oC core temperature. They were also cooked in steam to have the core temperature of 95oC. The samples were also subjected to autoclaving at a temperature of 121oC and 15 lb pressure. Result: The markers used in this study successfully amplified unique fragments for beef, carabeef, mutton, chevon, chicken, duck meat and dog meat. The sizes of the amplified products were 126 bp for beef, 226 bp for carabeef, 254 bp for mutton, 453 bp for chevon, 256 bp for chicken, 292 bp for duck meat and 100 bp for dog meat. The results were consistent in the meat samples which were subjected to different cooking temperatures ranging from 75-121oC. Consequently, these markers were validated for cross-amplification by checking them with other meat samples and no amplifications were observed in non-target species. The results suggested that all the markers were highly specific for the target species. The simplicity, sensitivity and stability of the assay indicated that this method could be very useful for meat authentication and thereby to detect adulteration.