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Документ Investigation of the appearance and elimination of pinking coloration in white wines(2022) Bilko, Marina; Gunko, Sergiy; Babich, Irina; Naumenko, Oksana; Mukoid, Roman; Ischenko, Mykola; Doboniy, Inna; Danylenko, Svetlana; Bovkun, Alla; Stotska, OlenaInvestigation of the appear¬ance and elimination of “pinking” phenomenon in white wines is pre¬sented in the paper. Several factors that can cause pinking were ana¬lyzed: the degree of grapes ripeness and enzymatic treatment. The effect of fining agents based on polyvin¬ylpolypyrrolidone (PVPP) on the elimination of “pinking” was deter¬mined. It was proved that pinking in wines decreases with an increase in the sugar content in grape. This is explained by a decrease in the content of anthocyanins at the end of technical ripeness of grape. Experimental studies confirmed that the use of pectolytic enzymes with cellulase, hemicellulase, β-glucanase activities increases the intensity of straw color and the appearance of body tones, but does not affect pinking. Such treatment contributed to a slight increase in the content of phenolic compounds in wine materials, but did not affect the content of anthocyanins and “pinking” susceptibility. Treatment of wine materials with complex PVPP-based agents including sor¬bents and flocculants, is an effec¬tive way to eliminate the “pink¬ing” phenomenon. This reduces “pinking” in wine materials from 70…90 % to 1…2 %. This is due to the presence of sorbents and floc¬culants in the fining agents, which react with phenolic substances that cause “pinking” in white wines, and remove them from the system. So, there are reasons to argue that processing grape at the end of tech¬nical ripeness will contribute to a lower “pinking” susceptibility of wine materials; pectolytic enzymes did not affect the appearance of this phenomenon in white wines, and PVPP-based fining agents together with bentonite, activated carbon, gelatin or casein, are an effective way to reduce the “pinking” sus¬ceptibility of wine.Документ The influence of tannin preparations on the content and form of anthocyanins of model wine systems in the conditions of induced oxidation(2019) Bilko, Marina; Ishchenko, Mykola; Tsyhankova, Olena; Yakovenko, Tetiana; Кyrpel, Т.The article considers how oenological tannins effect on the content of anthocyanins, phenolic substances, and their forms that influence thestability of the colour of rosé and red wines. The research material was wine model systems that underwent induced oxidation for a week at a temperature of 45±5 °Cwith limited access ofair. Tannins of different botanical origin were used in the study:hydrolyzable ones–OaktanFU (oak wood), TannalW4 (Tara pods), CW Tannal (chestnut wood),and Tannal W2 (gallnuts); and condensedones–Tannin WG (grape stones), Taniraisin (grape skin), TannalQW (quebracho wood). The source of anthocyanins was an alcohol extract from the skins of European red grapes. It was obtained by 24 hours long extraction with ethyl alcohol, and with the addition of hydrochloric acid (0.01%).It has been determined that in the course of induced oxidation, the content of phenolic compounds tends to decrease in a wavelike manner in all samples. The anthocyanin content reduces intensively and becomes practically twice as low on the first day of oxidation. The total amount of phenolic compounds becomes 2 to 6 times lower depending on the variant of the experiment.It has been established that condensed tannins of grape origin contribute to the preservation of the total content of phenolic substances (including anthocyanins) in wine, unlike hydrolyzable tannins obtained from other plants.But their application leads to polymerization of anthocyanins, which will result in the appearance of yellow-brown pigments in the red colour of wine. Hydrolyzable tannins obtained from gallnuts and tara trees preserve the red colour of wine for a long time, unlike condensed tannins, due to their antioxidant capacity. Hydrolyzable tannins obtained from tara and quebracho trees will help obtain wine with rich red shades.