Development and validation of a multiplex real-time PCR assay for accurate authentication of common buckwheat (Fagopyrum esculentum) and tartary buckwheat (Fagopyrum tataricum) in food

Abstract

The increased demand for accurate information on ingredients listed on food product labels requires identifying a plant's species of origin. To efficiently and rapidly discriminate between common buckwheat (Fagopyrum esculentum) and tartary buckwheat (Fagopyrum tataricum), here we developed a multiplex real-time PCR assay. This assay included target species-specific and shared primer/probe sets representing the two buckwheat species. Multiplex real-time PCR analyses specifically amplified the target species without detectable cross-reactivity with nontarget plant samples. The detection limit was 1% for common buckwheat in tartary buckwheat and 2% for tartary buckwheat in common buckwheat. The method was verified through application to processed products and was confirmed through comparison with the food label information. The species identified were identical to those declared on the product label. Therefore, this multiplex real-time PCR assay will serve as a sensitive and specific diagnostic tool for detection of buckwheat species in foods.