The fundamental requirement when testing for and ensuring compliance with legally required labelling regulations is the reliable analysis of food allergens. This can be carried out by means of either DNA (deoxyribonucleic acid) or protein detection. Protein detection has the advantage of directly detecting the allergenic component and can currently be carried out using immunological (enzyme-linked immunosorbent assay [ELISA])/lateral flow devices [LFD]) or mass spectrometry-based techniques. DNA detection is indirect, but allows the presence of food allergens to be validated through the use of another marker. Each method has its pros and cons, which have to be considered on a case-by-case basis. ELISA is quantitative, quick and easy to carry out and has high sensitivity. LFD testing is ideal for industrial applications, as the tests can be carried out on-site. Both antibody-based tests may have problems with processed foods and false positive results. Mass-spectrometric techniques show a lot of promise, but are currently still time-consuming and complex to carry out. They also run into problems with processed foods and their degree of sensitivity is matrix and parameter dependent. For these reasons, this technique is only occasionally used. Polymerase chain reaction (PCR) provides the highest specificity and, depending on the target sequence, a very good to good level of sensitivity. Despite the high stability of DNA, PCR is still subject to the influence of processing and matrix related factors. Due to natural variation and production-related changes in the structures relevant in the process of detection, all methods exhibit a relatively high level of uncertainty of measurement. At present, there is no method which provides the absolute correct quantification. 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 methods that are already available.
Keywords: Allergen analysis; Allergen detection; Enzyme-linked immunosorbent assay (ELISA); Mass spectrometry (MS); Polymerase chain reaction (PCR).