Detection of allergenic ingredients using real-time PCR: a case study on hazelnut (Corylus avellena) and soy (Glycine max)

Compliance with the European allergen labeling legislation (Directive 2007/68/EC) is only possible when coupled with appropriate methods to detect allergens in food. The aim of the current study was to develop new real-time PCR assays for the detection of hazelnut and soy and evaluate these assays via comparison with commercially available kits. Although the new assays were not as sensitive as the commercial qualitative assays, they proved to be more specific. Moreover, the cross-reactivity study indicated contamination of some of the food products used with either hazelnut or soy, which presents a risk for the allergic consumer. The assays were able to quantify as few as 5-15 genome copies. This unit, used to express analytical results for allergen detection by means of PCR, needs to be converted to a unit expressing the amount of allergenic ingredient in order to be informative. This study emphasizes that the use of real-time PCR for allergen quantification is complicated by the lack of appropriate reference materials for allergens.