COLORIMETRIC METHODS FOR DETERMINATION OF AROMATIC ALCOHOLS IN BEER

Abstract

Methods for the determination of phenylethanol, tryptophol and tyrosol in beer have been developed. Phenylethanol is isolated by distillation and extraction from the distillate with methylene chloride. The concentration is determined by the Kapeller-Adler method. Tryptophol and tyrosol are extracted from the beer with ethyl acetate and separated by chromatography of a chloroform solution using a silicic acid-alumina column. Tryptophol is not adsorbed and tyrosol is eluted with ethyl acetate; other phenols are retained on the column. Tryptophol is determined with the vanillin-HCl reagent and tyrosol with the Diazo reagent or Millon's reagent.