A proteolytic effect of Oenococcus oeni on the nitrogenous macromolecular fraction of red wine

The proteolytic activity of Oenococcus oeni protease on the release of indi vidual amino acids and peptides from a red wine macromolecular nitrogenous fraction was evaluated. 148.7 mg l(-1) of individual amino acids were relea sed and a difference of 109.5 mg l(-1) with respect to the amino acids libe ration from white wine was observed. Stimulatory amino acids for O. oeni gr owth, glutamic acid and proline, were the most important amino acids obtain ed by the protease activity. In the HPLC and spectral analysis of peptides before and after the protease activity of O. oeni, several changes have bee n observed. Three new peaks, six higher and one lower have been found in th e chromatogram obtained after the enzyme action. The specific activity of O . oeni protease is higher on the red than on the white wine proteins and th is is important considering the lower protein concentration in red wine. (C ) 1999 Federation of European Microbiological Societies. Published by Elsev ier Science B.V. All rights reserved.