APPLIED FRUIT SCIENCE, cilt.67, sa.4, 2025 (SCI-Expanded)
Hazelnut is a nut with high nutritional value and is consumed with pleasure by consumers. However, due to the allergenic proteins it contains, it can cause serious allergic reactions in individuals with a sensitive immune system. The phenomenon of hazelnut allergenicity arises from the immune system's atypical reaction to specific proteins present in hazelnuts. In this context, the identification and classification of hazelnut allergens is critical in the diagnosis and treatment of allergy. Of particular significance are the so-called Cor a proteins, which are the principal allergenic components of hazelnut. This study was to assess fold change in the expression of Cor a 1, Cor a 8 and Cor a 11 in various commercial hazelnut cultivars cultivated in Turkiye (Corylus avellana cvs. 'Allahverdi', 'Cakildak', 'Fo & scedil;a', 'Giresun Melezi', 'Kalinkara', 'Okay 28', 'Palaz', 'Sivri', 'Tombul' and 'Uzunmusa' and Corylus colurna (known as Turkish hazelnut)). In this study, the fold change in the expression of Cor a 1 allergen of the 'Sivri' and 'Fosa' cultivars was significantly higher than that of the other hazelnut cultivars. Unlike Cor a 1, the highest gene expression fold change in Cor a 8 allergen was determined in the 'Uzunmusa' cultivar. As with other allergens, it was observed that the 'Sivri' and 'Fo & scedil;a' cultivars had similar levels of gene expression fold change in Cor a 11 allergen and were significantly (P < 0.05) higher than other hazelnut cultivars. It was observed that the gene expression fold change detected in the 'Okay 28' hazelnut cultivar was significantly lower than all cultivars. As a result, it was revealed that the levels of fold change in gene expression of Cor a protein in hazelnut cultivars were variable, with the 'Sivri' and 'Fosa' cultivars exhibiting higher values in terms of fold change.