Citrus fruits enjoy widespread consumption globally, being among the most popular fruits. They are highly regarded for their nutritional composition, offering a range of beneficial nutrients. However, it's important to acknowledge that they can also elicit allergic reactions in sensitised individuals, which presents a contrasting aspect. Bet v 1 cross reacting allergen is major birch pollen allergen and it the most commonly sensitizing allergen in central Europe. Bet v 1 belongs to the group of PR-10 proteins in the plant kingdom that cause a various allergic reactions. Bet v 1 allergen has a number of isoforms and homologues. These homologues genes are inherited from a common ancestor and subsequent amino acid similarity. It can cause the phenomen cross-reacticity in food allergies. The aim of the study was analysing the length polymorphism variability of the Bet v 1 homologs in orange varieties by using degenerated and nondegenerated primers. A total of 8 varieties of Citrus sinensis L. Osbeck were used in the analysis. BBAP technique (Bet v 1 based amplified polymorphism) was used to detect the length variability of fingerprints of allergen encoding genes of Bet v 1 homologs. Degenerated primer combination and only a one from nondegenerated variant of primers provided fingerprints, that were unique for every individual variety of analysed oranges. In all other primer variants, from 2 up to the 4 varieties generated the same BBAP profile, what indicate the higher degree of Bet v 1 homologs seguentional conservativity when compared to other fruit species.

Funding: This publication was supported by the Operational program Integrated Infrastructure within the project: Demand-driven research for the sustainable and innovative food, Drive4SIFood 313011V336, co-financed by the European Regional Development Fund.