Free amino acids and volatile compounds in vinegars obtained from different types of substrate

The present work reports on the free amino acids and volatile compounds in vinegars obtained from different types of raw materials (cider, white wine and red wine). Based on the amino acid contents of three types of vinegar and of the substrates from which they were obtained, the profile of the nitrogen supplying compounds and their uptake for the acetic acid bacteria were very similar. The most important amino acid in terms of supply and uptake was found to be (L)-leucine. L-Proline proved also important in the wine vinegars, however it was not depleted as L-leucine. The different acetification reactions involved were found to yield acetoin, and plus 1,1-diethoxyethane in the wine vinegars. (C) 2004 Society of Chemical Industry.