Tannins organoleptic properties

Filtering. Conditioning or 1 agering gives the beer its desired organoleptic properties, but it stiU contains yeast, protein-tannin complexes, etc, ie, it has a hazy appearance. A high quaHty beer must be clear and totaUy sterile, have coUoidal stabiHty, and yeast must be removed to aUow the beer to have biological stabiHty. The protein-tannin complexes must also be removed so as not to upset the coUoidal stabiHty. 

In the last part of the book some examples are reported on the importance of the contribution of chemical studies to fields that are of increasing concern for the public opinion such as health, food, and the environment. One of these describes investigation of the protein-tannin interaction in order to better understand organoleptic properties of foodstuffs, and in particular those of red wine. 

Among organoleptic properties used for quality assessments of wines, astringency deserves particular attention. This complex sensation in the mouth occurs after tasting red wines, which are known for their characteristic high concentration of polyphenolic compounds called tannins. Neither the perception of astringency nor its molecular basis is understood fully, but it is accepted... 

Tannins and Anthocyanins of Wine Phytochemistry and Organoleptic Properties... 

On the other hand, careful use of global values, based on the specific properties of tannins, may be of assistance in interpreting certain characteristics of a wine, including stability and organoleptic qualities (Glories, 1978a). 

The overall organoleptic impression is based on a harmonious balance between these two types of sensations, directly related to the type and concentration of the various molecules, such as anthocyanins, and especially tannins. One of their properties is to react with glycoproteins in saliva (mucine) and proteins in the mouth wall, modifying their condition and lubricant properties. A study of the reaction of the B3 procyanidins with synthetic, proline-rich proteins showed that three dimers were strongly bonded to the protein chains (Simon et al., 2003). According to the type and concentration of tannins, they may produce a soft, balanced impression or, on the contrary, a certain aggressiveness that is either perceptible as... 

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