We evaluated the chemical composition and antioxidant activity of 30 red wines from Austria (cv. Cabernet-Sauvignon, Blaufraenkisch and Zweigelt) and 20 wines from Montenegro (cv. Cabernet-Sauvignon and Vranac) from three consecutive vintages: 2014, 2015 and 2016. We determined spectrophotometrically the contents of total phenol (TP), total anthocyanin (TA) and low- and high-molecular-weight proanthocyanidins (LMP and HMP respectively). We identified and quantified 18 phenolic compounds (hydroxycinnamic acids, hydroxybenzoic acids, stilbenes and flavan-3-ols) by high-performance liquid chromatography. In addition, we used Fourier-transform infrared spectroscopy for chemical analyses of the main wine parameters. Austrian autochthonous wines exhibited a similar chemical composition (alcohol 12.4 vol%, pH 3.38). Blaufraenkisch wines showed higher TP, HMP and LMP than Zweigelt wines; however, TA content was similar. Blaufraenkisch wines also showed higher phenolic acid, flavan-3-ol and stilbene contents than Zweigelt wines. Montenegrin autochthonous Vranac wines showed a typical chemical composition (alcohol 13.0 vol%, pH 3.42), and medium to high levels of phenols: TP, HMP, LMP, TA, HCA and flavan-3-ols. On the other hand, they showed a moderate stilbene content. Cabernet-Sauvignon wines from Austria and Montenegro exhibited some similarities in phenolic composition: TP, HMP, LMP and TA. There were notable variations in the phenolic acid and flavan-3-ol contents, especially the stilbene content, which was much higher in the Austrian wines than in the Montenegrin wines. These findings evidence an important impact of climatic conditions on these compounds. The antioxidant activity in all investigated wines was high and correlated strongly with TP, total phenol index, HMP and LMP in wines. The vintage influenced the chemical composition and content of all examined phenolic groups, except flavan-3-ols. Wines from the vintage with the best maturity (2015) contained the highest content of spectrophotometrically determined phenolic compounds and lowest level of phenolic acids and stilbenes. Principle component analysis showed that wines were mainly discriminated by variety and origin but not by vintage.

In Montenegro, red wines are produced predominantly, and Vranac accounts for nearly 80% of these wines, followed by Kratosija and Cabernet Sauvignon. In order to characterise polyphenols in red varieties, grapes were sampled from representative vineyards at harvest time during 2011 and 2012. The content and distribution of extractable anthocyanins, low-molecular mass proanthocyanidins (LMP) and highmolecular mass proanthocyanidins (HMP) in the seeds and skins of the grape berries were evaluated by applying a five-day extraction method using ethanol:water (12:88) as extraction solvent. On average, the highest content of LMP (2 006 and 1 690 mg/kg of grape fresh mass in years 2011 and 2012 respectively), HMP (2 705 and 2 805 mg/kg in years 2011 and 2012 respectively) and anthocyanins (1 035 mg/kg in the year 2011) was found in the Cabernet Sauvignon grapes. The highest content of anthocyanins (1 113 mg/kg in the year 2012) and the lowest content of LMP (1 103 and 846 mg/kg in years 2011 and 2012 respectively) was found in Vranac grapes. Kratosija grapes had the lowest anthocyanin content (456 and 517 mg/kg in years 2011 and 2012 respectively), and levels of LMP were similar to Vranac. The percentage distributions of LMP between skins and seeds were 34:66, 39:61 and 49:51, whereas the distributions of HMP between skins and seeds were 67:33, 62:38 and 64:36 for Vranac, Kratosija and Cabernet Sauvignon respectively. All varieties had more LMP in the seeds and more HMP in the skins of the grapes. The results obtained are important to better understand the polyphenolic potential of Montenegrin red grape varieties.

This paper presents the results of a study that examined the impact of grape variety on the volatile aroma compounds and sensory properties of standard and Muscat grape brandy produced in the Podgorica sub-region (Montenegro) in vintages 2011, 2012, and 2013. The brandies were prepared by the distillation of crushed grapes, from the autochthonous varieties of Vranac and Kratošija, and Muscat grapes, in a traditional copper alembic, under the same conditions. The gas chromatographic-mass spectrometric (GC/MS) method of 82 volatile aroma compounds that belong to the group (alcohols, volatile acids, volatile esters, terpenes, volatile aldehydes, acetals, ethers, ketones, and alkanes) and an evaluation of the sensory properties of brandies were carried out to determine the typical characteristics of the examined brandies. Alcohols, fatty acid esters, and terpene compound contents were significantly more abundant in all Muscat grape brandies compared to the brandies from the Vranac and Kratošija wine varieties (Standard brandy). Research results revealed that variety had a significant impact on the volatile aroma compound and sensory properties of brandy. The varietal effect was also confirmed, by multivariate analysis, based on the aroma volatile composition, which showed a grouping by type of grape brandy (varietal origin). Sensory analyses showed that all the brandies belonged to the category of high-quality brandies.

Polyphenolic compounds, including total phenolics (TP), total anthocyanins (TA) and total flavan-3-ols (TF3-ols), as well as color intensity (CI) and hue (H), determined by spectrophotometric methods, were studied in Montenegrin red wines from Vitis vinifera L. cv, Vranac. Wines were produced by traditional and modern fermentation methods, applying different oenological products (enzyme, oak chips and grape tannins) during two vintages, i.e. 2008 and 2009. Wines produced from the 2009 vintage presented a slightly higher average amount of total phenols (2,878 mg/l) compared to the wines from the 2008 vintage (2,570 mg/l), and similar contents of anthocyanins and flavan-3-ols. The use of modern fermentation tanks (Sifa and Ganimede) followed by the addition of enzymes, oak chips and grape tannins resulted in a higher amount of polyphenolic compounds. Principal components analysis allowed for the grouping of wines according to the vintage and maceration method.

Research of origin and work on clonal selection of Montenigrin grapevine varieties cv. vranac and cv. kratosija