Detection of Cashew Nut in Foods by a Specific Real-time PCR Method

Appropriate detection methods have to be provided to assure the compliance with the recently established regulatory provisions concerning the labeling of allergens in food. Therefore, a novel real-time polymerase chain reaction (PCR) system for the specific and sensitive detection of cashew nut (Anacardium occidentale) was developed. Specificity was checked against DNA from 56 plant and animal species to avoid cross-reactivity to phylogenetically related and other food-relevant organisms. The absolute limit of detection (LOD) was determined to be 0.5 pg genomic cashew DNA and 10 copies, respectively, and the practical LOD examined exemplarily for pesto Genovese was 2 mg/kg. In addition, analysis of different retail samples was performed to demonstrate the suitability of the new assay for manifold applications.