Functional ingredients to improve wine making
The tannins in Tan’Activ® provide many functions in both red and white wines, depending on their chemical structure. Below are the most important properties:
In oenology, tannins are mostly used to complex unstable proteins in the wine. The hydrogen bond that tannin forms with the protein is the same as that created in a sensorial way by tannins and salivary protein. Proline, the main protein component of saliva, binds the tannin and the precipitate obtained creates the sensation of astringency on the palate as a result of the reduction of its lubricant action. Tannins are used as filter aids in order to clarify must and wine without changing the aromatic structure.
The gray mould, caused by the fungus Botrytis cinerea, is one of the most important diseases occurring in the vineyards and thus affecting the quality of the wine. Botrytis cinerea causes oxidation reactions with polyphenols and aromatic precursors of the wine. The use of tannins as antioxidants inhibits the action of the main oxidase enzymes responsible for the degenerative process, as the grape tyrosinase as the fungal laccase.
Tannins enhance the antimicrobial properties of sulphur dioxide, inhibiting the growth of microorganisms.
The stabilisation of the colour during winemaking is a fundamental step to increase the longevity of a good red wine. The use of tannins, both hydrolysable and condensed, integrates the natural tannin textures present in wine and promotes the formation of stable complexes with anthocyanins in the case of red wines and flavonols in the case of white wines. Moreover tannins preserve the polyphenols naturally present in grapes, maintaining an unaltered typical taste and sensory perception.
Improvement of the organoleptic characteristics of wines
Tannins, especially the hydrolysable, give structure and flavour to wines that are lacking in texture and taste. The oak tannins enhance the smell and taste of the finest wines, bringing lovely vanilla and liquorice notes, as well as roundness and mouthfeel. They also mask the herbaceous and bitter notes of polyphenols. Among the condensed tannins, those from grapes and green tea are the most suitable for improving the structure and flavour profile of wines.
Capture of thiols
Tannins are able to produce hydroperoxides and free radicals, which can complex and destroy thiols and mercaptans, which are responsible for the unpleasant smell typical of cabbage and onions. This bad smell is formed during alcoholic fermentation due to poor hygiene, the presence of lees and the excessive use of sulphiting agents.
The ability to capture free radicals is typical of all the tannins, especially hydrolysed tannins. They can reduce the incidence of coronary heart disease among wine drinkers, particularly in the case with red wine.
Another important property of hydrolysable tannins, especially for gallotannins, is to complex metals such as copper and iron, forming chelate complexes that precipitate, thus reducing the metal content in solution.