Study of the migration of benzophenone from printed paperboard packages to cakes through different plastic films

Benzophenone is one of the most commonly used photoinitiators, which are mostly used in UV-cured inks for which drying times are much shorter than for conventional solvent or water-based coatings. Benzophenone levels were determined in different packaging materials used for cakes, to evaluate the safety of printed paperboard intended for food contact. For this, a simple extraction method and a rapid specific reverse-phase high performance chromatography method with UV detection were developed. Benzophenone was quantified in different samples by a rapid specific reverse-phase high performance chromatography method after extraction with acetonitrile at 70 degrees C for 24 h. A novel method for testing benzophenone diffusion towards plastics was also developed and different experiments were conducted in order to measure diffusion coefficients at 70 degrees C for 2 days and at 40 degrees C for 10 days. Polypropylene plastics sleeves were found not to be an effective barrier against benzophenone diffusion (3,800 mu g/g of benzhophenone was found after 48 h at 70 degrees C in cakes protected with this film) whereas, the corresponding value in cakes wrapped with a multilayer film of PP/EVOH/PP was reduced to 1,400 mu g/g, and the concentration of benzophenone in cakes wrapped with a multilayer film of PET/SiOx/PE was negligible.