Applicability of the International Analytical Approach for Detection of Hazelnut Processing Residues: Collaborative Experiment

Hazelnuts are a prevalent food allergen that can trigger adverse immune responses in susceptible individuals. The demand for hazelnut residue detection in food and processing is increasing. This work presents a universal method using the Cor h 1 gene fragment from Chinese hazelnuts and the Cor a 1 gene from European hazelnuts as real-time PCR targets. Collaborative experiments between domestic and international laboratories validated the method's sensitivity, repeatability, robustness, inclusiveness, and specificity. The false-positive and false-negative rates were analyzed, along with absolute detection limits and probability. This method detects residues from most global hazelnut species, with a LOD6 of 0.01%, LOD95% of 2.5 copies/PCR reaction, theoretical median laboratory LOD95% of 3.553, POD of 0.642, and interlaboratory standard deviation of 0.424. Food sample testing confirmed good applicability. Approved by ISO, this method is being promoted as ISO/AWI TS 24910-2 to become an ISO standard.