Monitoring the carryover of egg proteins in pasta making to support allergen risk management

Egg proteins are among the major food allergens. Very often, the same pasta-making plants are used for industrial production of egg-based pasta and semolina-only pasta, so that residual egg proteins may be present in semolina-only pasta. This calls for defining the amount of semolina pasta that should be discarded when switching production lines. In this study, the egg proteins content was measured in pasta samples taken at various times after switching production lines from egg-containing pasta to semolina-only pasta. Both long and short pasta shapes were sampled, both before and after a drying step. Protocols meant to circumvent the difficulties associated with detecting egg proteins in a complex matrix after processing were set up for using commercial ELISA kits to monitor the disappearance of egg proteins from the products. The use of both denaturants and disulfide reductants to solubilize egg proteins was found to be mandatory, as verified by ovalbumin detection by ELISA tests and by using mass spectrometry to assess residual egg white lysozyme. Therefore, appropriate sample preparation protocols were used to monitor the progressive disappearance of egg proteins in the products when shifting production lines in an industrial pasta plant, providing a basis for credible, reliable, and consistent self-control procedures. For lines with a production capacity of 2200-2400 kg h-1, the amount of material to be discarded to ensure that products meet appropriate analytical requirements has been found to be around 2000-3000 kg (for long pasta) and 3000-4000 kg (for short pasta).