A novel single-tube nested real-time PCR method to quantify pistachio nut as an allergenic food: Influence of food matrix

In this work, five nuclear genes (Pis v 1, Pis v 2, Pis v 3, Pis v 4 and Pis v 5) were investigated for their potential application as specific markers for pistachio nut. Pis v 2 gene was selected as the best marker for pistachio identification and targeted by a novel single-tube nested real-time PCR method. The approach allowed ampli-fying 1 pg of pistachio nut DNA (1.6 copies), as well as 100 and 5 mg/kg of pistachio nut in wheat material (pasta) or ice-cream, respectively, being successfully validated regarding precision/trueness. Wheat material (pasta) matrix affected sensitivity, still maintaining acceptable performance parameters, including precision and trueness. Ice-cream matrix presented the lowest Cq values, thus enabling a more efficient amplification. Herein, a highly sensitive, specific and cost-effective single-tube nested real-time PCR targeting the Pis v 2 gene is pro-posed, for the first time, as a novel quantitative and validated approach for pistachio nut analysis as an allergenic food.

Automated summary

In this study, five nuclear genes were investigated as potential markers for pistachio nut. The Pis v 2 gene was identified as the best marker and targeted using a single-tube nested real-time PCR method. The method showed high sensitivity and successfully detected pistachio nut in wheat material and ice-cream. This novel approach provides a cost-effective and validated method for the analysis of pistachio nut as an allergenic food.