Protein quantification, sandwich ELISA, and real-time PCR used to monitor industrial cleaning procedures for contamination with peanut and celery allergens.

In the United States, peanut is one of the main sources of food allergens. Similarly, celery is a common allergenic food in Western Europe. Severe allergic reactions to both foods are common. Unexpected allergic reactions can occur after the consumption of celery- and peanut-free foods as a result of inadvertent cross-contaminations during manufacturing. Therefore, in cooperation with a flavor manufacturer, we monitored the cleaning process of slurry preparation equipment with regard to contaminations of follow-up products with celery and peanut compounds. Washing water samples taken after different cleaning steps and follow-up products were analyzed for the presence of celery and peanut traces with a celery-specific real-time polymerase chain reaction (PCR) and a peanut-specific sandwich enzyme-linked immunosorbent assay (ELISA). PCR and ELISA were compared with a nonspecific protein assay to evaluate whether the detection of protein traces can be a fast and cost-effective method for monitoring the effectiveness of wet cleaning procedures. Additionally, the allergenic potential of the celery and peanut mush, which were used as source material, were measured by a mediator release assay using a rat basophilic leukemia (RBL) cell line. In conclusion, the quantification of total protein in washing water was suitable for monitoring the cleaning process. Our study also revealed evidence that, in cases where wet cleaning is applicable, allergenic traces can be removed with high efficiency.