A study of the chemical composition of apples of various varieties growing on the farms of the Krasnodar Territory

Abstract

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.