LIGHT-INDUCED SENSORY AND CHEMICAL-CHANGES IN AROMATIC BITTERS

Every month for a year, samples of aromatic bitters stored in clear an d green bottles under conditions relevant to the retail trade, (1) in sunlight, (2) in fluorescent light and (3) in the dark, were character ized by descriptive sensory analysis, tristimulus colorimetry and by t he concentrations of 13 flavour compounds, Aromatic bitters stored in light developed a higher intensity of sweet and solvent-like odour, de scribed by the assessors as catty-like or ribes. Bitters stored in lig ht had a stronger tendency to become turbid and these samples had a fo rtified-wine-like flavour and were less bitter and less astringent. A new method in this context, growth curve analysis, was used successful ly to detect significant time and treatment effects in the sensory dat a. By partial least-squares analysis only a minor part of the light-in duced sensory effects in bitters could be accounted for by the concent ration of flavour compounds.