Food matrix standards for the quantification of allergenic food ingredients using real-time PCR

For the quantification of food allergens by real-time polymerase chain reaction (PCR), food matrix standards with defined levels of spiked allergenic food ingredients can be used. The production and homogeneity testing of selected materials as sausages, cookies and sauce hollandaise powder is described. Except for egg and milk, all relevant allergenic ingredients were spiked to each material. Allergens were spiked and quantified as food ingredients, for example, peanut or lupine flour, at levels of 5–400 mg/kg. Material with sufficient homogeneity could be produced even at low levels of 5–10 mg of the allergenic ingredient per kilogram. The effect of the food matrix on allergen quantification was checked. The bias caused by this effect was in an acceptable range for the tested materials. The materials produced within this study were used as samples and for calibration in inter-laboratory validation studies for the quantification of allergenic food ingredients by real-time PCR. The results of this study are a contribution how to produce such reference materials for allergen analysis in the near future. Before threshold or action values of allergens in food are set, the availability of reference materials is essential.