In Russia, fruit wines produced using existing technologies do not yet fully compete with grape wines, as they are inferior to them in terms of organoleptic characteristics and storage stability. In connection with the expansion of the production base of fruit wines and ciders, it is necessary to intensify the study of the chemical composition of local varieties of apples, its changes that occur during alcohol fermentation, as well as throughout the entire technological process for the production of fruit wine, in order to obtain a high-quality product. We studied apple varieties Idared, Golden Delicious, Jonathan, Interprise, Florina, Renet Simirenko, Kore, growing in the Krasnodar Territory, and wines made from them. It has been established that the qualitative composition and concentration of sugars, as well as the organic acids of apple juices, is determined primarily by the varietal characteristics of apples. During the fermentation process, the amount of titrated acids changed. The concentration of malic acid decreased, and lactic acid increased markedly, which led to a softening of the taste of fermented juice and an improvement in its organoleptic characteristics. In apple juices, various groups of phenolic compounds have been identified. The highest concentration of anthocyanins, tannins and catechins was detected in apple varieties with colored skin - Jonathan and Idared. During fermentation, the concentration of phenolic compounds decreased in all fermented juices in comparison with fresh ones. It can be concluded that during fermentation, the main role in biochemical processes is played not only by the varietal characteristics of apples, but also by the physiological properties of the yeast race.

Исследована активность основных окислительных ферментов – ортодифенолоксидазы (ОДФО) и пероксидазы (ПО) в сусле и виноматериалах, произведенных из винограда классических сортов и их клонов и новых сортов – внутри- и межвидовых гибридов. Эксперименты проведены без обработки сусел и вин диоксидом серы и бентонитом. Установлено, что активность ОДФО и ПО имела наибольшие значения в образцах сусел из винограда гибридных сортов Цитронный Магарача, Виорика и Бархатный. Сбраживание сусел приводило к снижению активности окислительных ферментов вследствие их трансформации или сорбции дрожжевыми оболочками. Аналогичная закономерность установлена для сусел и виноматериалов из винограда красных сортов: наибольшая активность ОДФО выявлена в образцах сусла из винограда новых сортов – Алькор, Красностоп анапский и Красностоп АЗОС, характеризующихся высоким накоплением фенольных соединений. Достаточно высокую активность ПО имели образцы из винограда сортов Алькор, Владимир, Мицар. Сбраживание сусел из винограда всех исследованных красных сортов привело к уменьшению активности окислительных ферментов ОДФО и ПО в виноматериалах, однако это снижение было менее существенным в сравнении с образцами белых столовых вин. The activity of the main oxidative enzymes – autodependencies (AD) and peroxidase (PO) in the must and wine produced from classic grape varieties and their clones and new varieties of intra - and interspecific hybrids were investigated. The experiments were carried out without processing of the must and wines by sulfur dioxide and bentonite. It was found that the activity of АD and PO had the highest values in the samples of grape-based hybrid grape varieties Tsitronnyy Magaracha, Viorika and Barkhatnyy. Fermentation of the must led to a decrease in the activity of oxidative enzymes due to their transformation or sorption by yeast shells. A similar pattern is set for must and wine from red grapes: the greatest activity, АD found in samples of the must from grapes of new varieties Alkor, Krasnostop anapskiy and Krasnostop AZOS, characterized by a high accumulation of phenolic compounds. Samples from grapes of Alkor, Vladimir, Mitsar varieties has rather high activity PO. Fermentation must of grapes from all the studied red varieties led to a decrease in the activity of oxidative enzymes AD and PO in wine materials, but this decrease was less significant in comparison with samples of white table wines.