Isolation, purification and identification of major allergens Cor a 9 and Cor a 14 in hazelnuts

Hazelnut (Corylus avellana) is a widely consumed nut with potent allergenic potential, and the isolation and purification of native hazelnut allergens are critical for the effective prevention and management of hazelnut allergy. In this study, two major allergens Cor a 9 and Cor a 14 were purified from hazelnut kernels via a sequential protocol involving pulverization, defatting, protein extraction, ammonium sulfate precipitation, dialysis desalting, and anion-exchange chromatography. Results demonstrated successful purification of the target allergens with high purity and intact conformational structure, which exhibited specific immunoreactivity with sera from hazelnut-allergic patients. A single preparation run yielded over 5 mg of Cor a 14 (purity >95 %) and more than 1 mg of Cor a 9 (purity >85 %). The established protocol is simple, requires minimal equipment, and offers high efficiency, laying a preliminary foundation for hazelnut allergen-related research. In conclusion, we successfully isolated and purified two major hazelnut allergenic proteins Cor a 9 and Cor a 14, providing a valuable material basis for investigating the sensitization mechanism of hazelnut allergy and developing diagnostic tools or hypoallergenic products.