Influence of conditions of preparation of wheat grain wort and blackcurrant cake on yeast metabolism and alcoholic fermentation processes

The relevance of the study is due to the need to expand the range of competitive alcoholic beverages with original organoleptic properties and ensuring effective import substitution. The previously obtained results on the use of blackcurrant cake in the technology of grain and fruit wort preparation revealed the difficulties of joint processing of raw materials and showed the need for their separate preparation followed by their combination at the stage of saccharification and proteolysis. There is practically no data on the effect of the biochemical composition of grain and fruit wort on the growth and metabolism of yeast cells. The purpose of these studies was to develop conditions for the joint processing of wheat grain and blackcurrant cake to produce a wort that improves the efficiency of yeast generation, ethanol synthesis, and volatile metabolites. blackcurrant cake, a secondary resource of juice production, was used as an unconventional raw material. The conditions for the preliminary preparation of the cake have been developed, including treatment with xylanolytic enzymes followed by pasteurization and alkalinization to pH 4.5. The use of fermented cake (pH 4.5) in the joint preparation of the raw materials of wheat and blackcurrant wort had a positive effect on its performance: the viscosity decreased by 1.7 times, the concentration of soluble carbohydrates increased from 22.0 to 25.1 %, phenolic substances – almost 2 times. The peculiarities of the composition of wheat-blackcurrant wort had a positive effect on the processes of yeast metabolism and alcoholic fermentation, which led to an increase in alcohol yield by 22…27 %, a decrease in the formation of secondary metabolites by 10…17 %, mainly due to a decrease in the synthesis of higher alcohols. At the same time, the concentration of esters increased (by 29…38 %), which can affect the appearance of original shades in the aroma and taste of distillates. A schematic diagram of the complex processing of wheat and blackcurrant cake in the technology of grain-fruit distillates with original properties has been developed.