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A study for determination of the volatile composition of distillates with the addition of 50% and 70% ethanol extracts of St. John's wort (Hypericum perforatym L) was conducted. The extracts were added in amounts of 20, 80, 100, 200, 400 and 600 ml. The remaining amount to liter was pure distillate obtained from the grapes of the variety "Melnik-55". Gas chromatographic (GC-FID) analysis for identification and quantification of the volatile components in the distillates obtained was performed. Various compounds from the groups of esters, higher alcohols, aldehydes and terpene alcohols have been identified. The methanol levels were found to be highest in the control sample (364.74 ± 0.32 mg/dm3) and proportionally decreased with increasing of the fraction of added extract in the experimental variants. This contributed to obtained of the alcoholic distillate with decreased methanol content. A similar decrease in the amounts of acetaldehyde and ethyl acetate was observed. This reduced the harmful aromatic nuances that these compounds impart when they were in higher amounts. Four major higher alcohols have been identified - 3-methyl-1-butanol, 2-methyl-1-butanol, 2-butanol and 1-propanol. The ester composition was diverse, quantitatively dominated by the presence of ethyl acetate. A higher total terpene content was detected in the samples with the addition of Hypericum perforatym L extract compared to the control. This indicated increased final concentrations in the distillates (a consequence of the terpene composition of the herb), which may intensify its biological effect. The produced distillates with added extracts of Hypericum perforatym L can be used for obtaining of new higher alcoholic beverages with added medicinal herb extracts. [ABSTRACT FROM AUTHOR]

The influence of the technological practices of maceration and addition of aroma-releasing enzyme before the alcoholic fermentation on the chemical composition, aromatic profile and organoleptic characteristics of white wines from three consecutive harvests (2013, 2014 and 2015) was studied. The subject of the study were wines from the varieties Dimyat, Aligote, Muscat Ottonel, Misket Vrachanski and Plevenska Rosa, grown in the region of Pleven, Central Northern Bulgaria. The dynamics of grapes ripening and the weather conditions impact on the grapes composition and quality were monitored. Aligote was distinguished by the highest ratio of sugar accumulation, followed by Plevenska Rosa. Grapes from white aromatic varieties were characterized by lower total acidity compared to the non-aromatic. In the conditions of the experiments carried out, the maceration had an influence mainly on the chemical composition of the wines. These variants had higher rate of sugar-free extract and total phenolic compounds, but no higher tasting scores than the control. Positive impact of the maceration and the addition of aroma-releasing enzyme on the ratio of esters and higher alcohols in the samples was observed, but not on the aldehydes concentration. It was not found a strict correlation between the aromatic composition of the wines and their organoleptic characteristics. From the aromatic varieties, the variants containing more esters and fewer aldehydes and higher alcohols have been evaluated higher. [ABSTRACT FROM AUTHOR]

The effect of the oenological practices, maceration and maceration with the addition of aromatic enzyme before the alcoholic fermentation on the composition, aromatic components and organoleptic profile of experimental wines from the local varieties Dimyat, Muscat Vrachanski and the newly-selected variety Plevenska Rosa was studied. The investigation was carried out during the period 2013-2014, with grapes and wine from the studied varieties grown in the soil and climatic conditions of the town of Pleven (Central Northern Bulgaria). The applied technological practices had increased the sugar-free extract and the total phenolic compounds content in the experimental samples. The highest rates for these indicators revealed the variants of Plevenska Rosa variety. The amount of esters and higher alcohols was greater in the wines obtained after maceration and maceration with the addition of aromatic enzyme in the grape must. The total esters concentration was the highest in the samples of the aromatic varieties Muscat Vrachanski and Plevenska Rosa. There was not observed a direct correlation between the applied oenological practices, enhancing the extraction and the aromatic components content in the experimental variants and their organoleptic profile. [ABSTRACT FROM AUTHOR]