Detection of Allergens

One of the important parameters for food safety is the absence of food allergens. Therefore, EU regulations have become into force during the last years (2003/89/EC and 2006/142/EC). These regulations predict product labeling of food allergens on base of the method of preparation. Besides of that, unintended contamination with allergens can occur during transport- and production- processes. For this reason, reliable methods for the detection of allergens are unmistakable.

Testing of allergens can be performed at the level of proteins or otherwise at the level of DNA. Various protein-based tests for allergens are available. Among these tests which make use of mono- or polyclonal antibodies are the fast dipstick tests. In order to gain insight in the presence of specific allergenic proteins, immuno-blotting experiments can be of interest. In this type of test also serum from allergic patients can be incorporated. In order to quantify the presence of allergens in food matrices, most frequently the so-called ELISA test methods are used. Most commercially available ELISA kits claim a limit of detection between 1 and 5 ppm.

In addition, DNA based methods for the detection of allergens become more relevant. Especially PCR type of assays show an ultimate sensitivity due to the amplification of low copy numbers of DNA. Moreover, it has been shown that DNA based detection methods are in general less sensitive towards so-called matrix effects. Further, the efficacy of DNA tests can be increased by the combination of various allergic tests in a so-called multiplex format.