This study aimed to show aromatic profile of wines produced from two autochthonous grape cultivars Krstac (K) and Zizak (Z). During the wine production two enzymatic preparations (EP) Lallzyme cuvee blanc (CB) and Lallzyme enzymatic preparation ? (EB) and different time of skin contact (4 and 8 h) were applied. Aromatic compounds were detected by GC/FID?MS analysis. Significantly higher content of total detected aromatic compounds compared to appropriate controls (168.54 and 161.72 mg L-1) was observed for K EB4h (176.33 mg L-1) and Z CB4h (177.29 mg L-1) wines. Skin contact and usage of EP mostly increased content of 2-phenylethyl and isoamyl alcohols. Wines from both varieties showed higher content of hexanoic and octanoic acids compared to the control. It is interesting to emphasize that content of esters that are responsible for fruity aroma of wine which is important for pleasant taste (isoamyl acetate ? banana, ethyl hexanoate ? ripe banana, 2-phenylethyl acetate ? powerful fruity rose like) were increased in all samples compared to the controls. The highest grades, after sensory evaluation, were obtained for K EB 8h (18.0 out of 20.0) and Z CB 8h (18.2 out of 20.0).

Krstač and Žižak are autochthonous grape varieties grown in Montenegro. Although international varieties are more popular, the autochthonous varieties are very important, especially for countries developing tourism. The fermentation aromas produced during alcoholic fermentation contribute significantly to wine quality. The effects of yeasts (Saccharomyces cerevisiae and Saccharomyces bayanus) and yeast nutrients (Fermaid E and Fermaid O) on aromatic compounds in wines were investigated. Using GC/FID-MS analysis, aroma compounds in Krstač and Žižak wines were characterized and quantified. Wines produced with the addition of yeast and yeast nutrients had mostly lower total alcohol content than wines obtained by spontaneous fermentation of Krstač and Žižak varieties. The results of this study showed that the concentration of compounds depends on the yeast strains. The yeast S. cerevisiae (ICV) provided a higher content of higher alcohols, while S. bayanus produced a higher concentration of esters and (medium chain) fatty acids. Total ester content ranged from 3.34 to 11.97 mg/l for Krstač wines and 8.51 to 13.68 mg/l for Žižak wines. Among all wines, Krstač and Žižak wines produced with S. bayanus and Fermaid E addition had the highest concentration of total esters. The yeast nutrients Fermaid E and O emphasized different characteristics of the yeasts. They had a statistically significant effect on the content of ethyl and acetate esters. The highest overall scores were obtained for ICVE and BayE Krstač wines (18.1 out of 20 points) and Žižak ICVE wine (18.2 out of 20 points).

The aim of this study was to investigate the influence of two lactic acid bacteria strains (Lactobacillus plantarum, Oenococcus oeni) and a bentonite treatment on the content of aromatic compounds in wines of the autochthonous grape varieties Krstač and Žižak. Higher alcohols, medium-chain fatty acids (C6, C8, C10), esters and other volatile compounds were detected by GC/FID-MS analysis. The concentration of higher alcohols was lower in the wines from Krstač and Žižak in which malolactic fermentation was performed. The results of this study showed that the content of aromatic compounds depends on the lactic acid bacterial strains. L. plantarum yielded a higher content of total higher alcohols and esters compared to O.oeni. The content of total esters ranged from 30.28 to 32.70 mg/L for Krstač wines and from 19.35 to 23.21 mg/L for Žižak wines. O. oeni and L. plantarum had a statistically significant effect on the concentration of most esters. Lactic acid bacteria significantly reduced the content of ethyl butyrate, ethyl hexanoate, ethyl decanoate and isoamyl acetate. Furthermore, the content of ethyl lactate, diethyl hydroxybutanedioate, diethyl succinate and ethyl hidrogen succinate was higher in wines produced with L. plantarum. The addition of bentonite in increasing concentrations did not affect the concentration of the higher alcohols in Žižak wines. The lowest content of fatty acids was detected in wines produced with 200 g/hL bentonite.

Pre-fermentative treatments are essential in winemaking, as they significantly influence the quality and stability of white wines in particular. The synthesis of many compounds obtained from yeast, such as higher alcohols and esters, is influenced by the type and concentration of aromatic precursors present in the must, especially amino acids. Clarification has a positive effect on wine quality, mainly by improving organoleptic properties, with flavour being the most affected. In this study, the influences of different static settling times, different pressures during must extraction and the addition of different bentonite concentrations to the must on the aroma of wines from the autochthonous grape varieties Krstač and Žižak were investigated. The identification of aromatic compounds in the wine was performed using GC/FID-MS analysis. Wine subjected to the longest static settling time (30 h) showed the highest concentration of esters. Krstač wine, which underwent a 30 h of settling, was characterised by an increased concentration of esters, such as isoamyl acetate, ethyl decanoate and ethyl hexanoate, while Žižak wine was characterised by the presence of 2-phenylethyl acetate and isoamyl acetate. The total fatty acid content in Krstač wine obtained by pressing was higher (14.90 mg/L) than in wine produced from free-run juice (8.04 mg/L).