BADGE was added at known concentrations ('spiked') into foodstuffs (sunflower oil, water, tuna in sunflower oil, tuna in water and apple pur
e), which were then canned, sterilised and stored at room temperature or at 50 C. BADGE was also 'spiked' into bottled beers (ale, lager and stout) under an atmosphere of carbon dioxide. The beers were recapped and stored at 40 C. The spiked samples were analysed at defined times and the concentrations of BADGE and its hydrolysis products were measured.
Modelling studies were carried out reacting BADGE with free amino acids, proteins and sugars. High pressure liquid chromatography (HPLC) was optimised to detect these reaction products. The BADGE-protein mixtures were also digested using enzymes prior to analysis.
Deuterium-labelled BADGE was synthesised and spiked into tuna in sunflower oil; apple pure; ale; lager; and stout samples. The samples were extracted and analysed as for non-labelled samples and also using Fourier Transform Mass Spectrometry (FT-MS) which enabled the exact mass and hence the elemental composition of the peaks to be determined. Enzyme digests were carried out to try to release any BADGE bound to proteins.
The finding in the mid-1990's of bisphenol A diglycidyl ether (BADGE) migration from certain can coatings led to an explosion of publications on the measurement of BADGE and its then-known reaction products. These products are formed by BADGE reacting with hydrochloric acid in heated polyvinyl chloride lacquers to form chlorohydrins, and with water to form the corresponding mono- and diols. Although the formation of these reaction products is well documented, it is believed that they do not account for all the products that can derive from BADGE when it migrates into some foods. For example, when BADGE was spiked into tuna and then processed under typical canning conditions of 121
C for 30 minutes, the added BADGE disappeared almost completely and could not be accounted for by the known reaction products. It was postulated that the BADGE epoxy groups could be reacting with nucleophiles in the food.<p>
This work aimed to confirm that BADGE levels decayed in some canned foods and that new reaction products formed between BADGE and food components. In addition it was hoped that new knowledge and understanding could be gained on the extent of these interactions and the identity and concentration of reaction products.
BADGE may be considered as an example of a more general case, especially for epoxy additives but also for other reactive substances, for which information on reaction products and transformation products is desirable.
<p>Find more about this project and other FSA food safety-related projects at the <a href="http://www.food.gov.uk/science/research/" target="_blank">Food Standards Agency Research webpage</a>.