High resolution melting analysis as a new approach to detect almond DNA encoding for Pru du 5 allergen in foods

Almond is responsible for trigging adverse immune responses in allergic individuals, and since it is present in many processed food, it is considered as a potential hidden allergen. Here we propose a novel, simple and highly specific approach to detect almond in a wide range of processed foods. The method consists of a real-time PCR assay targeting the gene encoding for the Pru du 5 allergen in almond, using the fluorescent EvaGreen® dye combined with high resolution melting (HRM) analysis. The new approach allowed the detection of trace amounts of almond down to the level of 0.005% (w/w) and was successfully applied to processed foods. HRM analysis increased the specificity of the assay and was effective in distinguishing almonds from other plant foods, including the closely related fruits from the Rosaceae family. It was demonstrated for the first time that HRM analysis can provide a powerful tool for the identification of allergens in foods.