THE INFLUENCE OF TECHNOLOGICAL PROCESSES OF GRAPE PROCESSING ON THE FORMATION OF PHYSICOCHEMICAL AND ORGANOLEPTIC INDICATORS OF WINES MADE FROM GRAPES OF THE RIESLING REIN VARIETY

Abstract

The technological processes of grape processing in modern conditions are actively evolving in directions necessary to form a commercially attractive organoleptic profile of wine, especially in the context of further global warming. New technological developments focus on reducing alcohol content in wines, preserving the typicity, freshness, and acidity of white wines, and avoiding excessive oxidation, particularly at the initial stages of grape processing. The purpose of the study is to investigate the impact of grape processing technological processes on the formation of physicochemical and organoleptic indicators of wines produced from Riesling grapes. The tasks included examining the influence of different pressing methods, stabulation, and pre-fermentation cold maceration on the physicochemical and organoleptic properties of white wines made from Riesling grapes, comparing the characteristics of wines using sensory analysis methods, and conducting statistical data processing. A comprehensive analysis of the research results shows a significant impact on the formation of primary aroma intensity. The greatest impact was observed in the whole cluster pressing and stabulation variants. In the whole cluster pressing variant, the lowest concentration of phenolic substances is observed, suggesting that the low concentration of these compounds in the must, and subsequently in the wine, reduces the rate of oxidation processes, in which phenolic substances act as catalysts for conjugated oxidation. Wines from Riesling grapes grown in Ukraine showed a much larger number of primary aroma clusters in the variant where must pressing was used, although their intensity was lower by 15% to 50%, depending on the aroma cluster. There was no correlation between the mass concentration of reduced extract and taste intensity. Correlation between phenolic substances and primary aroma intensity was observed in the stabulation variant. In the case of using cold maceration, an increased amount of phenolic substances was observed. In the case of cold maceration with Gaia, biological deoxygenation occurs, which restrains oxidative processes and allows for the extraction of primary aromas from the grape skins during contact with the juice.