Bottle aging influence on wine qualitative indicators from interspecific grape varieties

The aim research is to study the effect of bottle aging on the biochemical composition and organoleptic properties of dry white wines prepared from interspecific grape varieties growing in the Rostov Region. The study was carried out on the basis of the laboratory for quality control of grape and wine products and the laboratory of wine technology ARRIVandW, a branch of FSBSI FRASC. The objects of research are wines from white technical grape varieties: Hungarian selection (Bianca, Lakhedyimezysh, Kristall) and ARRIVandW selection (Platovsky, Donus, Stanichny), control variety - Aligote (Vitis vinifera L.). Physicochemical analysis and organoleptic evaluation of dry white wines prepared from the studied grape varieties were carried out in the process of aging in a bottle for a period of 1 to 3 years in the enoteca of the institute. Chemical analysis revealed that in wines from the varieties Platovsky, Aligote, Stanichny, Lakhedyimezesh there was a decrease in alcoholic content by 0.3-0.9 % by volume, associated with the oxidation of ethyl alcohol to acetaldehyde during aging. In all samples, a decrease in the concentration of titratable acids and the reduced extract was observed. The greatest decrease in the content of titratable acids was noted in wines from the varieties Aligote (1.8 g/dm3), Lakhedyimezesh (1.1) and Donus (1 g/dm3) (they were distinguished by a softer and more harmonious taste). In all experimental wines, a decrease in the concentration of phenolic substances by 7-31 % was observed, associated with their oxidation during aging. The highest oxidation of phenolic substances (31 %) was observed in wines from the Platovsky variety; in the same wines, a deterioration in organoleptic properties was noted, since the presence of a rather large amount of oxidized phenolic compounds gives it specific tones in aroma and taste that are not characteristic of dry white wines. The content of volatile acids in wines was in the range of 0.59-0.98 g/dm3 and did not exceed the standardized limits (for white wines - up to 1.1 g/dm3). In all samples, with the exception of wine from the Kristall variety, the content of nitrogenous substances (total and amine nitrogen) decreased by 10-20 %. According to the tasting assessment, the highest score was given to wine samples from the control variety Aligote (8.7-8.9 points), wines from the grape varieties Stanichny, Donus and Lakhedyimezesh (8.6-8.7 points) were slightly inferior to it (8.6-8.7 points), in which during the aging process a bright varietal aroma was preserved, the bouquet developed for the better (light harmonious taste with a pleasant aftertaste).