Effect of Barrier Film Containing Hydroxybenzophenone or Titanium Dioxide on Light Induced Chemical Changes in Aquavit

The protective effect of low density polyethylene (LDPE) film coating containing 5 g/kg or 100 g/kg hydroxybenzophenone or 5 g/kg or 20 g/kg titanium dioxide (TiO2) on light-induced chemical changes in caramel coloured aquavit have been investigated. Accelerated storage experiments were performed using a photochemical reactor. Aquavit samples were analysed by tristimulus colorimetric measurements and by gas chromatographic determination of limonene, linalool, carvone and the carvone photoproduct, carvonecamphor. In noncoated bottles, the tristimulus colour parameters L*- and a*-values of aquavit increased and b*-values decreased with light exposure. The rate of these changes was reduced by coating the bottles with film containing TiO2or hydroxybenzophenone, with greatest effects at high concentrations. Formation of carvonecamphor was prevented by coating with film containing 100 g/kg hydroxybenzophenone or 20 g/kg TiO2. Film with 5 g/kg hydroxybenzophenone reduced the rate of formation of carvonecamphor by 80% and 5 g/kg TiO2reduced the rate to approximately 50%.