Potential DNA markers as a rapid tracing tool for animal adulterants in vegetarian food

DNA-based methods are rapid, cost-effective and broadly applicable approaches for food authentication. Recently, the requirements for food safety and food integrity have increased with improved quality of life. Methodologies regarding food authentication based on DNA analysis are more commonly being used. With the increasing number of vegetarians, searching for markers for blind identification across kingdom species, such as an ingredient of animal origin in vegetarian food, would be valuable and attractive. Using bioinformatic analysis of an existing data source composed of 481 ultraconserved sequences, we selected 6 new candidate DNA segments that exist in most vertebrates but that do not exist in plants. Then, primers were designed for all of the candidate DNA markers, and DNA samples isolated from cow, pig, chicken, duck, soy bean, rice, pepper, wheat, sunflower and colza were amplified using each primer pair. None of the plant DNA samples generated a PCR product, while the DNA samples of animal origin were amplified successfully using 5 of the candidate segment primers; the 6th segment primer failed to amplify the DNA and was discarded. Moreover, a simulation experiment containing a plant product contaminated by an animal component indicated that the candidate DNA markers can be used for the rapid detection of animal adulterants in vegetarian products with a promising 5% detection limit. The identified candidate DNA markers for the blind identification of animal adulteration in vegetarian food may be highly desirable in the vegetarian food market, and these markers may facilitate the study of molecular technology for food authentication. (C) 2015 Elsevier Ltd. All rights reserved.