Pine nuts shell sorbent influence on the organic acids composition and apple wines volatile components

The purpose of research is to study the composition of organic acids and volatile impurities in apple wine. As an object of study, we used apple wines obtained by fermentation of fresh squeezed and clarified juice from the fruits of a small-fruited apple tree of the Krasnaya grozd' variety. The resulting apple must was fermented using a pine nut shell nozzle (sample 2). As a control sample (sample 1), wine material obtained by fermentation of the same apple must without the use of a nozzle was used. The paper presents experimental data on changes in the content of organic acids and volatile components of wine during fermentation using pine nut shell packing. A decrease in the duration of the fermentation process by 96 hours is shown. In the studied samples of apple wines, methanol, acetaldehyde, esters (ethyl acetate, methyl acetate) and higher alcohols (propanol-1, butanol-1, isobutanol and isoamyl alcohol) were identified by gas chromatography, the concentrations of which do not exceed the normalized values. In apple wine obtained using a nozzle, there is a decrease in the total content of esters from 49.5 to 47.0 mg/dm3 and higher alcohols from 368.4 to 270.1 mg/dm3. Among higher alcohols, the maximum content of isoamyl alcohol is (179.6 mg/dm3) and the minimum amount of propanol-1is (44.6 mg/dm3). A change in the content of such organic acids as citric, tartaric, malic, succinic and lactic acids was noted. During the fermentation of the must using a nozzle in the finished wine, an increase in the concentration of biologically active succinic acid by 13.7% was found. The results of the study allow us to recommend the use of pine nut shell packing in the production of low-oxidized white wines.