ИССЛЕДОВАНИЕ БИОХИМИЧЕСКОГО СОСТАВА ПЛОДОВ ЯБЛОНИ ЮЖНОГО ПРИБАЙКАЛЬЯ И ПРОДУКТОВ ВИНОДЕЛИЯ, СБРОЖЕННЫХ НА ДРЕВЕСНОЙ ЩЕПЕ

The present work is aimed at studying the biochemical composition of apple fruits growing in the Southern Baikal region, as well as the determining the qualitative characteristics of apple wine obtained by fermentation on wood chips under ultrahigh yeast concentration. The main physicochemical parameters and the total content of phenolic compounds in juices of six apple breeds are determined. For the fruits of 'Krasnoyarskiy Snegirek' variety, the content of macro- and microelements (Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, Zr, Pb and Ba) was analysed by X-ray fluorescence spectrometry. Among the macronutrients, K was established to be presented in the largest amount (0.762 %), while the quantity of Fe (0.006 %) appears to be significantly lower. An increase is detected in the qualitative characteristics of apple wine material during fermentation on wood chips under ultrahigh yeast concentration. The redox potential was shown to have decreased by 80 mV. The tasting score increased by 0.7 points. Additionally, the colour intensity decreased by 0.392 nm and the hue changed by 0.3 nm. The HPLC-UV-MS method was applied to study the change in the composition of phenolic compounds during juice fermentation. Phenolic compounds related to phenolcarboxylic acids (derivatives of aromatic hydrocarbons), derivatives of dihydrochalcones, flavan-3-ols and flavonols were identified in juices and wine materials. As compared to the control, a threefold decrease in the total amount of phenolic compounds during fermentation on wood chips was obtained. The must fermentation rate was confirmed to increase by 72 hours. The possibility of obtaining juices with increased nutritional value and low-oxidised white wines from winter-hardy apple breeds of the Southern Baikal region was demonstrated. The authors declare no conflict of interests regarding the publication of this article.