Rapid Full-Cycle Technique to Control Adulteration of Meat Products: Integration of Accelerated Sample Preparation, Recombinase Polymerase Amplification, and Test-Strip Detection

Establishment of rapid extraction and sensitive detection system of trace corn syrup DNA in honey

Honey adulteration with exogenous syrup has become a common phenomenon, and current detection techniques that require large instruments are cumbersome and time-consuming. In this study, a simple and efficient method was developed by integrating the rapid extraction of nucleic acids (REMD) and recombinase polymerase amplification (RPA), known as REMD-RPA, for the rapid screening of syrup adulteration in honey. First, a rapid extraction method was developed to rapidly extract corn syrup DNA in five minutes to meet the requirements of PCR and RPA assays. Then, the RPA method for detecting endogenous maize genes (ZssIIb) was established, which could detect 12 copies/μL of the endogenous maize gene within 30 min without cross-reacting with other plant-derived genes. This indicated that the RPA technique exhibited high sensitivity and specificity. Finally, the REMD-RPA detection platform was used to detect different concentrations of corn syrup adulteration, and 1 % adulteration could be detected within 30 min. The 22 commercially available samples were tested to validate the efficacy of this method, and the established RPA was able to detect seven adulterated samples in less than 30 min. Overall, the developed method is rapid, sensitive, and specific, providing technical support for the rapid field detection of honey adulteration and can serve as a reference for developing other field test methods.

Meat Authenticity Made Easy: DNA Extraction-Free Rapid Onsite Detection of Duck and Pork Ingredients in Beef and Lamb Using Dual-Recombinase-Aided Amplification and Multiplex Lateral Flow Strips

Meat adulteration is a major global concern that poses a threat to public health and consumer rights. However, current detection techniques, such as quantitative polymerase chain reaction (qPCR) and gas chromatography-mass spectrometry, are time-consuming and require sophisticated equipment. In this study, we developed a rapid onsite identification method for animal-derived ingredients by utilizing a fast nucleic acid lysis buffer to expedite the release of sample nucleic acids and combined it with dual-recombinase-aided amplification (dual-RAA) technology and visual multiplex lateral flow strips (MLFSs). Our method successfully detected duck- and bovine-derived, porcine- and bovine-derived, duck- and ovine-derived, and porcine- and ovine-derived meat in a rapid 20 min onsite detection assay, with a detection limit of 101 copies/50 μL reaction system for target genes. Moreover, our method accurately detected adulterated meat with proportions as low as 1:999. These findings have significant implications for food safety and the protection of consumer rights.

Rapid detection of duck ingredient in adulterated foods by isothermal recombinase polymerase amplification assays

Duck is often used in meat fraud as a substitute for more expensive meats. Rapid detection of duck ingredient in meat products is of great significance for combating meat fraud and safeguarding the interests of consumers. Therefore, we aim to develop duck-specific recombinase polymerase amplification (RPA)-based assays for the rapid detection of duck ingredient in animal-derived foods. Using Cytb gene as target, the real-time RPA and RPA combined with lateral flow strips (LFS RPA) were developed successfully for the rapid detection of ducks in 20 min at 39 °C and 40 °C, respectively. The assays did not show cross-reactions with 6 other livestock and poultry. The developed RPA assays could detect 10 pg duck genomic DNA per reaction and 0.1 % (w/w) duck ingredient in duck and mutton mixed powder within 30 min, including a rapid nucleic acid extraction. Furthermore, duck ingredient could be detected in 30 different actual foods including heat-processed meats and blood products. Therefore, duck-specific real-time RPA and LFS RPA assays were successfully developed with good specificity and sensitivity, which could enable rapid detection of duck ingredient in the field and provide technical support for combating the meat fraud.