DNA-based methods for species identification in food forensic science

Abstract Food adulteration is involved with economic, religious, legal, and public health issues, and therefore there is an increasing demand for authentication and certification of food products. Food forensics, in general, addresses food-related crimes, including mislabeling, adulteration, and the occurrence of foodborne pathogens in order to protect the sanctity and reputation of a product or organization. Highly priced food and processed food products are usually the targets of fraudulent labeling. Food authentication refers to the analytical process to ensure that product ingredients match the label description. A large number of analytical techniques have been developed and practiced, including chromatography, spectrophotometry, and enzyme-linked immunosorbent assay. However, DNA-based techniques are now considered highly promising and surpass the shortcomings of the earlier ones as DNA has been proved as the suitable target molecule for species authentication. Polymerase chain reaction (PCR) offers stringent specificity and sensitivity that permits the detection of food fraud even if this occurs at trace amounts and in processed food products. However, PCR-based techniques have limitations as they require good laboratory setup, sophisticated lab equipment, and skilled personnel. Recently, biosensors have attracted enormous attention from researchers and end users due to their unique features such as enhanced stability, portability, low cost, and widespread applications. The most popular and modernized form of a biosensor is electrochemical nucleic acid biosensor that combines the sensitivity of electroanalytical techniques with the inherent bioselectivity of nucleic acid. Despite noticeable achievements and progress in this sector, there are still multiple challenges to overcome and numerous issues to be resolved. This chapter focuses on the PCR- and DNA biosensor–based approaches giving examples of their applications in food authentication and foodborne pathogen detections.