SOME ASPECTS OF DISTILLATE PRODUCTION FROM JERUSALEM ARTICHOKE TUBERS. PART 2. BALANCE OF DISTRIBUTION OF VOLATILE COMPOUNDS BETWEEN FRACTIONS

Abstract

Distillation is a complex physico-chemical process consisting of ethanol concentrating and controlled regulation of volatile compound content in the product (distillate). Conditions of passing of volatile compounds into the distillate depend on many factors. These factors include the evaporation coefficient of the compound, its solubility in various ethanol concentrations, compounds’ mutual solubility in a multicomponent system, the rectification coefficient. The purpose of this research is to study the balance of distribution of volatile compounds between fractions («cuts») during distillation of fermented Jerusalem artichoke wort in a water- bath distilling plant. It has been discovered that extending of fermentation process and pre-saccharifying of the Jerusalem artichoke wort lead to methanol concentration increase in the distillate fractions. It has been discovered that the main part of methanol concentrates in the medium fraction. It is shown that during fermented wort distillation neoplasm of acetaldehyde and ethyl acetate takes place by 24-41% and 2.5-3.8 times. The clear dependence of acetaldehyde and ethyl acetate balance between the factions of the distillate on the method of raw material preparation and the time of fermentation has not been found. It has been found that overwhelming amount of 1-propanol, isobutanol and isoamyl goes to the middle fraction irrespective to the method of the raw material preparation for distillation and time of fermentation. Total amount of higher alcohols in the medium fraction is 74.6-96.9% to their concentration in fermented wort. Total amount of phenylethyl alcohol, a compound that gives the distillate flowery tones and the scent of honey, in the fractions is 11-25% to its initial concentration in the wort, herewith it concentrates in the tail fraction. The return of the tail fraction to a new portion of the distilled wort allows increasing the amount of phenylethyl alcohol in the distillate.

Keywords

• jerusalem artichoke
• fractional distillation
• volatile compounds
• neoplasm of volatile compounds