Managing allergenic risks at the industrial level: Egg proteins residues in pasta

Background. As of today, limits for allergens content in food have not been defined. Therefore, each industry set up a proper self-control manual that contains recommendations and risk evaluation. Egg proteins represent one of the major food allergens. The same pasta-making industrial plants are often used for production of both egg-pasta and semolina pasta, that may represent a risk for sensitive people since residual egg proteins may be present in semolina pasta. In this context it is fundamental to define the amount of semolina pasta, produced in egg-pasta line plant, that should be discarded. In this study, we assessed the amount of egg proteins in pasta samples taken at various time after the change from egg-pasta to semolina pasta. To investigate the role of drying in protein extraction, we detected the egg proteins in the same pasta samples before and after drying. Methods. Two commercial sandwich ELISA kits – from R-Biopharm and Morinaga - were used for egg proteins extraction and detection in fresh and dried pasta samples prepared with semolina and water on a production line previously used for the production of egg-containing pasta. Results. Recovery of egg proteins from the pasta matrix was only possible by using a combination of choatropes and reductants in the extraction medium. Pasta drying step decreased the amount of material extracted from the pasta with both kits, with noticeable differences. Appropriate protocols allowed monitoring the progressive disappearance of egg proteins from the industrial pasta, at least down to levels in the 0.8-1.0 ppm.