Cleaning for allergen hygiene

A study carried out in New Zealand by researchers at Auckland's AUT University and Tegal Foods has looked at the effectiveness of cleaning procedures for environmental allergen control.

The study focused on three processing lines that were used to process 11 different wheat-containing battered chicken products. Over the course of six months, 15 production runs were selected at random and surface swabs were taken to detect nonspecific protein and the wheat protein gliadin, after 3 increasingly rigorous cleaning steps. Gliadin was monitored in 14 production runs by immunoassay, protein (by the Coomassie dye method) was monitored in 5 production runs, and all 15 production runs were monitored by adenosine triphosphate (ATP) bioluminescence.

The researchers reported their results in arbitrary units. In a typical production run, gliadin values fell from 100000 arbitrary units pre-cleaning, to 6000 after rinsing, to 30 (foam, rinse), to not detected (sanitize, rinse). After comparing the measurements of gliadin, ATP bioluminescence and protein during the three cleaning stages, the authors concluded that ATP bioluminescence is probably a useful surrogate for residual gliadin and probably of residual protein.

Based on these results, they also modelled the risk of cross-contamination of gliadin in follow-up product. Working with a hypothesis that the line may unintentionally be left uncleaned between processing runs, they reported that all follow-up product could still be labelled gluten-free.

Reference: Wang et al. 2010. Journal of Food Science. Vol. 75(9). T149-55. DOI: 10.1111/j.1750-3841.2010.01854.x.