Stability of bisphenol A diglycidyl ether and bisphenol F diglycidyl ether in water-based food simulants

Varnishes used for the inner coatings of food cans are often based on epoxy resins or vinylic organosols. The epoxy resins can be produced from bisphenol A (BPA) and bisphenol F (BPF), and these also contain bisphenol A diglycidyl ether (BADGE) or bisphenol F diglycidyl ether (BFDGE) as stabilising components. These compounds may break down during storage and also by the influence of food simulants. The stability of BADGE and BFDGE were studied using reverse-phase gradient high-performance liquid chromatography (RPHPLC) with ultraviolet detection (UV). Three experimental conditions for spiked simulants were compared: (1) the storage at 25 C (C1), (2) the storage at 40 C (C2) and (3) the storage at 25 C after 15 min heating at 120 C (C3). Distilled water, 3% acetic acid and 10% ethanol were used as food simulants. It was observed that BADGE is more stabile than BFDGE. The loss of BADGE and BFDGE were minimal in 10% ethanol (39 and 46% at 25 C, 60 and 69% at 40 C, respectively) and highest in 3% acetic acid (60 and 63% at 25 C, 76 and 82% at 40 C, respectively). At experiment (C3), the hardest conditions, significant degradation was not shown in comparison with conditions (C1) and (C2), contrariwise BADGE and BFDGE in 10% ethanol were minimal degradated at conditions (C3) from all these experiments (loss of 5 and 8%, respectively).