Detecting Donkey Meat Adulterated with Duck Meat by Portable Fluorescence Quantitative PCR

To develop a fast and convenient method for the molecular identification of donkey meat products, this study selected donkey meat and duck meat (a common meat used for adulteration) as the research objects, screened specific primers and TaqMan probes, and conducted sensitivity and specificity experiments with a portable Mini8 Plus real-time fluorescence quantitative PCR instrument. By drawing the amplification standard curve and determining the mass/DNA ratio constants of donkey meat and duck meat, it detected the real donkey meat samples and the simulated samples adulterated with different proportions of duck meat (20%, 40%, 60%, and 80%, respectively). The results showed that the method had good specificity for both donkey meat and duck meat, which could be clearly distinguished from meat from horses, pigs, goats, sika deer, cattle, chickens, and dogs. The detection limit of donkey-derived DNA components was 0.01 ng/μL, and that of duck-derived DNA components was 0.1 ng/μL. Its sensitivity to duck meat components in the mixture of donkey meat and duck meat was 0.1% (w/w). The established standard curve showed a sound linear relationship. The amplification standard curve of donkey DNA was: y=−3.584x+27.003, R²=0.9982. The amplification standard curve of duck DNA was: y=−3.538x+30.907, R²=0.9991. A market pilot survey was conducted on 35 donkey meat samples using the established method, and revealed that 6 donkey meat samples (17.1%) contained duck meat. These results indicated that the real-time PCR method could be used for the rapid and accurate detection of other meat (such as duck meat) adulterated in donkey meat products. The combination of a simple detection procedure with a portable real-time PCR system provides technical support for food adulteration monitoring and control at the retail or market level.