, 2007 and Pele et al., 2007) reducing their usefulness. Effective food allergen management plans seek to minimise the use of such labels, such as the Voluntary Incidental Trace Allergen Labelling (VITAL) system in place in Australia, (Zurzolo, Mathai, Koplin,
& Allen, NVP-AUY922 chemical structure 2012). Such plans require access to well validated methods of allergen analysis. Currently these are largely lacking, partly because comparison of different allergen detection methodologies, such as enzyme-linked immunosorbent assay (ELISA), polymerase-chain reaction (PCR) based methods, and mass spectrometry based methods, cannot be developed as incurred reference materials are not readily available (Heick et al., 2011, Kerbach et al., 2009 and Taylor et al., 2009). The complexity of food matrices and their lack of stability over long periods of time (ideally several years) when stored at ambient temperature makes the preparation of incurred reference materials problematic.
This is further complicated for allergens where the hazard (and hence the analytical target of choice) is a group of allergenic protein molecules, which are prone to modification, aggregation and interactions with other food components selleckchem (e.g., lipids and starches) in complex processed food matrices (Mills, Sancho, Rigby, Jenkins, & Mackie, 2009). Although certified reference materials, such as egg and skimmed milk powder, are available and are being used as calibrants and standards in commercial assays for allergen analysis, none have been designed specifically for food allergen analysis. Calibrants and reference materials may also contain levels of protein modification atypical for food ingredients such as skimmed milk powder, possibly as a result of γ-irradiation used to extend BCKDHA shelf-life (Johnson, Philo, Watson, & Mills, 2012), and have not been evaluated
with regards their allergenic activity. The ultimate verification of a food ingredient’s allergenic activity is demonstrated by their ability to trigger an allergic reaction in a food allergic individual. A range of food ingredients have been used as the active components in oral food challenge procedures used for diagnosis of food allergies in double blind placebo controlled food challenge (DBPCFC) (Vlieg-Boerstra et al., 2011). DBPCFC was a cornerstone of allergy diagnosis in the EuroPrevall project (FOOD-CT-2005-514000) and made use of a standardised food challenge dessert matrix in which dry powdered food ingredients, including peanut, hazelnut, celery spice, skimmed milk and pasteurised egg white powder, could be blinded (Cochrane et al., 2011, Mackie et al., 2012 and Mills et al., 2007). Comprising cold swelling starch, cocoa powder, sugar and a small amount of corn oil and emulsifier as a texturising agent, powdered allergenic ingredients could be homogeneously incurred into the dessert matrix base, which was then hydrated prior to consumption.