LIGHT-INDUCED SENSORY AND CHEMICAL-CHANGES IN AQUAVIT

Aquavit in clear bottles was stored in sunlight, in fluorescent light and in the dark under conditions relevant for the retail trade. Every 2 wk over a 6 mo period, the odour and taste of the aquavit were chara cterized by descriptive sensory analysis and concentrations of volatil e compounds were determined together with tristimulus colour analysis. Formation of geranium-leaf odour and taste were the most pronounced l ight-induced sensory changes. The colour of the samples stored in ligh t was determined less green and yellow and the samples were bleached. Concentrations of many of the volatile compounds characteristic of aqu avit, including carvone, decreased in light. Carvonecamphor and limone ne photoproducts were formed by photochemical reactions of carvone and limonene, respectively. None of these photoproducts had geranium-leaf , odour by gas chromatography-olfactometry, but a compound with low od our threshold had. The compound could not be detected by flame ionizat ion. A photochemical reactor suitable for accelerated light storage of beverages was constructed. The sensory and chemical changes found aft er 8h irradiation in the reactor were similar to those taking place in aquavit stored for 4 mo in sunlight. (C) 1995 Academic Press Limited