Applying COI Barcode to Identify Animal Origin of Food

DNA barcoding possesses advantages of high resolution, high sensitivity, and capability in capturing as much identity information as possible. However, highly varying sources of food materials and a complicated supply chain bring about challenge to the application of barcoding methods. In this study, different barcode systems were compared to establish a robust method for tracing animal species in food. Experiments on food samples from mammal, poultry, and fish proved that a mini barcode system targeting a 192 bp COI gene fragment was able to accurately identify both raw and highly processed animal food. In order to distinguish species in a mixed food sample, cloning technique was used by which as low as 10% target animal ingredient could be detected. Testing of marketed food products verified the capability of the mini barcoding method in identifying illegally claimed product.