Non-enzymatic transformations of amino acids during wine aging
The formation of organoleptic properties of wine significantly depends on the presence of sugars, acids, tannins and coloring components in grape must – this is confirmed by centuries-old practice of wine making and theoretical studies of winemaking processes. But when tasting natural wines with the same composition and content of the above mentioned substances, it turns out that the taste and aroma of the two samples are very different. This proves that wine quality (including the bouquet) is determined by the composition and concentration of nitrogenous substances, which include proteins, peptides and amino acids. The latter, namely the influence of amino acids in wine on the physical and chemical properties of the beverage, will be discussed below.
Role of amino acids in wine production
Studies of winemaking technologies confirm that the quality of the finished wine is highly dependent on the amino acids present in the grape must. However, the nature of their transformation and the importance of their transformation products are still under debate.
- The researcher Ehrlich pointed out that fermentation produces higher alcohols that give wine special aromas – floral and fruity. On the other hand, wines made from grapes grown on humus soils are characterized by a high content of nitrogenous substances and have a coarse flavor. Accordingly, to improve wine quality, it is advisable to reduce the amount of amino acids. The dispute was settled by the works of E. Penno and S. Lafon-Lafourcade. Lafon-Lafourcade: according to the results of their research, yeast processing of amino acids leads to the formation of a large amount of syrupy oils and a small proportion of alcohols with an attractive odor.Another point of view on the importance of amino acids belongs to V.L. Kretovich and V.I. Nilov. According to it, deamination of amino acids occurs during fermentation, and yeast does not participate in this process. As a result, aldehyde, carbon dioxide and ammonia are formed. The by-products of the processes contribute to the enrichment of wine during aging, particularly madera and Tokay varieties. But it is worth noting that the resulting aromas harmonize with fortified wines, with little correspondence to the requirements for table and sparkling wines. Accordingly, the increase of nitrogenous substances in wine materials for preparation of table and sparkling wines is undesirable, which should be taken into account when applying new technologies in winemaking.
The catalog of INPROMINOX offers a wide range of equipment for winemaking: we have installations for medium-sized wineries and mechanisms for mini wineries.
