Juodųjų serbentų, aviečių, aronijų, obuolių ir rabarbarų vyno distiliatų šalutinių fermentacijos produktų, turinčių įtakos gėrimų saugai ir kokybei, tyrimai

Abstract

Fruit and berries have long been excellent raw materials for a wide range of soft drinks, juices, and wines. The potential of fruit and berries for use in the production of distillates and spirits is increasingly being explored worldwide. The definition and requirements for fruit spirits are laid down in Regulation (EC) No. 110/2008. Spirits are alcoholic beverages based on fruit or other sugar-containing parts of plants. They are produced by alcoholic fermentation followed by distillation. Fruit berry distillate is not only a mixture of water and ethanol. It is made up of many aromatic components which are produced during fermentation and contribute to the sensory characteristics of the drink, i.e., taste and aroma. The research aims to analyse the content of by-products in the distillates produced during the fermentation of wine by using different plant materials. It is important to mention that alcoholic fermentation is not exclusively an anaerobic process in which yeast breaks down sugars to ethanol and CO2 through anaerobic fermentation with heat release. Fermentation is the process that produces a whole series of by-products which determine the composition and sensory characteristics of the wine and, subsequently, the distillates. The plants used for the study were blackcurrants, chokeberries, rhubarb, apples, and raspberries, which are widely grown in Lithuania. All samples were found to have methanol concentrations below the EU legal limit. The content of other impurities, i.e., higher alcohols, aldehydes, and esters, in the distillates was found to vary depending on the raw materials used for fermentation. The highest ester content expressed as ethyl acetate in g/ hl a.a. was found in apple and chokeberry distillate (69.53±14.60; 63,73±13,38, respectively), while the lowest content was found in blackcurrant wine distillate. The highest amount of aldehydes expressed as acetaldehyde in g/hl a.a. was found in the rhubarb wine distillate 1017.59±3.24, and the lowest amount was found in the blackcurrant wine distillate 50.37±9.57. Higher alcohols expressed as 2-methyl propanol, g/hl a.a. were found highest in the chokeberry wine distillate at 117,82±9,43 and the lowest in the blackcurrant wine distillate at 32,44±2,59. As shown by the study, the composition of the distillates of different raw materials (different fruit and berries) fermented under identical conditions differed. The paper presents the study results and analyses the causality of the results obtained.