The Identification of Yak Meat Using Loop-Mediated Isothermal Amplification Method Coupled with Hydroxy Naphthol Blue for the Prevention of Food Fraud

Objective. Yak is found in the Qinghai-Tibet Plateau and represents a meat of high nutritional value and good flavor. However, the production of yak is limited, and yak meat adulteration is a growing concern in the marketplace. To protect consumer rights and prevent unfair competition, it is necessary to use an efficient assay to identify the species of yak meat rapidly and accurately being sold. Methods. Loop-mediated isothermal amplification (LAMP) combined with hydroxy naphthol blue (HNB) was used to identify potential adulterants. The specificity and sensitivity tests of yak-derived components were carried out to achieve the monitoring of yak-derived components. Results. The optimal color development was achieved with an external primer-to-internal primer ratio of 400 nmol/L : 1200 nmol/L, 1.5 mmol/L dNTP, and 0.32 U/μL Bst DNA polymerase with 5 mmol/L MgSO4 at 62°C amplification temperature. The detection sensitivity of LAMP-HNB for yak-derived DNA was up to 1 pg/μL. Conclusion. The LAMP-HNB assays provided a valuable tool for the identification of yak gene from adulterated meat. This further enabled the LAMP-HNB assay to be applicable in the identification of other meat products.