Effect of commercial mannoproteins on wine colour and tannins stability

Commercial oenological products containing mannoproteins have the purpose of preventing tartrate salts precipitation or achieving wines with a better mouth-feeling. The evaluation of the influence of three commercial mannoproteins on colour and tannin stability of three different red wines (two from Touriga Nacional and one from Alfrocheiro and Aragonês varieties) was studied. The evolution of colour through time was similar for all modalities, resulting in an increase of polymeric pigments and colour hue and a decrease of other parameters, suggesting that there was no influence of commercial mannoproteins on colour stability. The tannin profile evolution showed a possible stabilizing effect of one of the commercial products for tannins with an mDP between 8 and 14. It is possible that the commercial mannoproteins used in this work have some influence on the tannin aggregation evolution, contributing to the delay of tannin polymerisation in red wines.

► Commercial mannoproteins did not have an effect on colour stabilisation.
► Commercial mannoproteins did not affect the global tannin profile evolution.
► MP3 commercial mannoprotein stabilised growth of tannins with mDP between 8 and 14.
► There is an interaction between low and medium MW mannoproteins and proanthocyanidins.