CRISPR-based nucleic acid assays for food authentication

Food fraud threats the sustainable development of the food industry. Accurate and rapid techniques for food authentication can protect consumers' rights and interests, safeguard public health, and maintain the food market. Applying quantitative polymerase chain reaction (qPCR) or sequencing to detect nucleic acid components has been a specific and sensitive strategy for food authentication, yet requires trained personnel and costly equipment. The rapidly evolving clustered regularly interspaced short palindromic repeat (CRISPR)-associated (CRISPR/Cas) system has become an efficient toolbox to address the need for on-site and time-effective detection. In this review, we first outline the basic principles of the CRISPR/Cas system. Next, we summarize the features of pre-amplification and preamplification-free nucleic acid assays using CRISPR-based techniques. We highlight onsite nucleic acid tests for food authentication enabled by Cas effectors. Particularly, we exemplify approaches employing CRISPR-based tools for authentication analysis in food, including milk, halal food, seafood products, plant ingredients, and genetically modified organisms. Finally, we discuss the challenges of transforming CRISPR-based tools for practical use for food authentication.