Changes in the organic acids composition in dry white wines from interspecific grapevine varieties during bottle aging

The purpose of research is to study the effect of the composition of organic acids and their transformations on the quality of dry white wines made from new grape varieties bred by the All-Russian Research Ya.I. Potapenko Institute for Viticulture and Winemaking - Branch of the Federal State Budget Scientific Institution “Federal Rostov Agricultural Research Centre” (FGBSI FRARC), in the process of aging in the bottle for 12-36 months. Objectives - to conduct a qualitative and quantitative analysis of organic acids in experimental wines made from new white grape varieties during their aging in the bottle from 12 to 36 months and to identify their effect on the quality of the studied wines. The studies were carried out in the laboratory for quality control of grape and wine products. The objects of the study are dry white wines made from new grape varieties Platovsky, Donus, Stanichny (interspecific origin), control - Aligote (Vitis vinifera L.), aged in a bottle from 12 to 36 months in the oenoteka of the Institute. It was revealed that during bottle aging the content of organic acids changes. Their total amount (sum) in the tested wines decreased by 1.1-1.6 g/dm3. Tartaric acid underwent the greatest changes, its concentration in wines decreased by 0.8-1.3 g/dm3. We also note a decrease in the concentrations of malic (by 8.3-28 %) and succinic (by 13-30 %) acids as a result of the esterification reaction during the aging process. The organoleptic properties of wines are significantly affected by the ratio of tartaric and malic acids: experimental wines in which the ratio of these acids was more than 3 (Stanichny, Donus, Aligote) were distinguished by the most harmonious taste and developed bouquet. Wines from the Donus and Aligote grape varieties contained the largest amount of lactic acid compared to other experimental samples, they also had a softer and more harmonious taste.