Zuckeralkohole und myo-Inosit in Weinen und Sherries

Abstract

Alditols and myo-inositol in wines and sherries The alditols - erythritol, xylitol, arabitol, mannitol, sorbitol and myo-inositol - occur in increasing amounts in German wines as the quality of these wines rises. Especially in Auslese, Beerenauslese and Trockenbeerenauslese wines alditols can constitute as much as 17.5 % of the sugar-free extract and therefore are a significant part of it. These sugar alcohols surely are involved in the full-bodyness of wines just as glycerol is. The presence of sorbitol - even if higher than the tolerated amount of 70 mg/l - does not indicate a falsification with pomefruit juice. In Q.b.A. wines 5 of 12, in Kabinett wines 17 of 42 and in Spatlese wines 14 of 23 have higher amounts. Not one of the Auslese wines showed less than 84 mg/l sorbitol. Beerenauslese and Trockenbeerenauslese wines contained up to 989 mg/l of sorbitol. Mannitol, myo-inositol and arabitol were also detected in unexpected high quantities. The maximum amount of mannitol was nearly 13 g/l in a Trockenbeerenauslese wine : Nearly 2.5 g/l of myo-inositol and 2.3 g/l of arabitol were found in these high quality wines. All alditols are natural in wines. The high concentrations found presumably stem from their synthes is by Botrytis cinerea and by associated yeasts on grapes infected by this mould.