Über die Herkunft von Gluconsäure, 2- und 5-0xo-Gluconsäure sowie Glucuron- und Galacturonsäure in Mosten und Weinen

  • W. R. Sponholz
  • H. H. Dittrich
Keywords: Botrytis, bacteria, metabolism, must, wine, carboxylic acid, sugar, wine quality


Origin of gluconic, 2- and 5-oxo-gluconic, glucuronic and galacturonic acids in musts
and wines

Gluconic acid and their oxidation products 2- and 5-oxo-gluconic acid and also glucuronic acid are not of grape berry or grape must origin. The occurrence of these sugar acids in Botrytis infected berries and in the corresponding wines indicated initially the formation of these products by Botrytis. Other metabolites made a formation by acetic acid bacteria probable. Investigations of musts and berries infected by acetic acid bacteria showed that these metabolites are mainly produced by acetic acid bacteria. Application of pure cultures of acetic acid bacteria demonstrated that these bacteria are the main producers of sugar acids.
Therefore the influence of acetic acid bacteria on the quality of musts and wines - especially on high quality wines - is much higher than expected before. Some metabolites up to now seen as substances produced by Bot1ytis are mainly produced by the co-infecting acetic acid bacteria.