Enological approaches for the limitation of the cell wall polysaccharides-tannin interactions

Tannins are one of the main compounds responsible of red wine quality. These compounds are mainly present in grape skin and seeds and are transferred into must-wine during the maceration step of winemaking, but this transference is far for being complete. This could be due, among other causes, to extracted tannins being bound to skin and pulp cell wall polysaccharides, which are present in high concentrations in the must/wine.

To limit these interactions, some enological approaches have been tested. One of these approaches, conducted in a real vinification, was to include a settling step, similar to that which is common in white and rose wines, in a red wine vinification.

Another approach is the optimization of the use of cell wall deconstructing enzymes, that could reduce these interactions and increase the quantity of tannins in solution.

This research group has been studying different combination and form of addition (individually, set or sequential) of different hydrolytic enzymes, highlighting the use of comprehensive microarray polymer profiling methodology (CoMPP) for a major understanding of how the enzymes are able to degrade and unravel the multi-layer structure of the grape cell wall.

The use of enzymes can be also coupled in a winery with the application of ultrasounds, a combination that also increased the content of phenolic compounds in the final wine.