Effect of Buckwheat-Corn Wort Mix on Yeast Generation and Ethanol Synthesis

Buckwheat and its mixes with grain have good prospects as an alternative raw material for fermented beverages with unconventional sensory properties. However, the use of buckwheat in alcoholic distillates remains understudied. The article describes the effect of different compositions of buckwheat-corn wort mixes on yeast generation, carbohydrate and nitrogen consumption, ethanol synthesis, and fermentation by-products. The research featured buckwheat, corn, wheat grain, enzyme preparations, and yeast Saccharomyces cerevisiae 985-T. A set of standard biotechnological and analytical methods was used to prepare the grain-buckwheat wort and control the ethanol synthesis processes and side metabolites. The grain-buckwheat wort samples had different shares of buckwheat. Adding buckwheat to the wort early during fermentation catalyzed the yeast growth by 1.5 times and ethanol synthesis by 1.4 times. However, the ethanol concentration and alcohol yield in the buckwheat-corn and corn mashes were almost equal after 42 h of fermentation. As for volatile metabolites, their composition and quantity depended on the fermentation stage and the buckwheat content in the wort. The maximum metabolites (309.6 mg/dm3) in the buckwheat mash occurred after 20 h of fermentation; the maximum metabolites (506.4 mg/dm3) in the corn mash developed after 70 h of fermentation. The buckwheat and buckwheat-corn mashes had a low content of higher alcohols and a high content of esters, which can affect the olfactive profile and taste of tr aditional alcoholic beverages. In this research, the targeted composition and concentration of grain wort components made it possible to obtain alcoholic beverages with alternative physicochemical and sensory profiles.