Current Pitfalls in Allergen Analysis
Martin Roder,
Food Chemist, Head of Food Allergens,
Institute For Product Quality
The reliable analysis of food allergens is the prerequisite for ensuring compliance with legally required labelling regulations. This can be carried out by means of either protein or DNA detection. Protein detection has the advantage of directly detecting the allergenic component and can currently be carried out using immunological (ELISA/simple rapid tests) or mass spectrometry-based (MS) techniques. DNA detection is indirect, but allows the presence of food allergens to be validated through the use of another marker. The advantages and disadvantages of each method need to be considered on a case-by-case basis. Qualitative simple rapid testing is ideal for food industry, as the tests can be carried out on-site. ELISA is quantitative, easy to carry out and has high sensitivity. Both antibody-based tests may have problems with processed foods.MS shows a lot of promise, butis currently still time-consuming and complex to carry out. MS runs into similar problems with processed foods and the sensitivity is dependent of matrix and parameter . Thus, this technique is only occasionally used. PCR provides the highest specificity and, depending on the target sequence, a very good to good level of sensitivity. PCR is still affected by influence of processing and matrix related factors. All methods exhibit a relatively high level of measurement error due to natural variation and production-related changes in the molecules relevant in the process of detection. However, by means of laboratory-based analyses it is possible to calibrate for the allergen in question and thus be able to make reliable measurements using the methods which are already available.
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