Food safety and label claims for hazelnut allergy traces: evaluation of two PCR assays

Abstract

The molecular techniques (C-PCR, RT-PCR) in the detection and quantification of allergic substances of hazelnut in various categories of food commodities, e.g. breakfast cereals, chocolates and biscuits, frequently involved in allergic outbreaks was implemented. For the detection of hazelnut a gene coding the major allergenic protein Cor a1 was selected. In some instances, the presence of hazelnuts is not declared on the label and the products may carry no warning for potentially allergenic substances, usually referred to as “traces”. A total of 150 samples were collected from local supermarkets and analysed for the purpose of the study. From these, a total of 38 (25.3%) specimens contained hazelnut, 30 (20.0%) contained “traces” of hazelnut, 26 (17.3%) contained a label warning for the possible presence of “traces” of allergenic substances, and 56 (37.3%) specimens contained no food allergy labels. Among them, using the C-PCR, 36 (94.7%), 10 (33.3%), 5 (19.2%), and 5 (8.9%) specimens were detected as positive, respectively. Using the RT-PCR, 38 (100%), 15 (50%), 7 (26.9%) and 8 (14.3%) specimens were detected as positive, respectively. Finally, by combining both methods, 38 (100%), 17 (56.7%), 9 (34.6%), and 10 (17.9%) specimens were identified as positive, respectively.