Effect of Must Hyperoxygenation on Sensory Expression and Chemical Composition of the Resulting Wines.

This paper evaluates the effect of must hyperoxygenation on final wine. Lower concentrations of caftaric acid (0.29 mg·L-1), coutaric acid (1.37 mg·L-1) and Catechin (0.86 mg·L-1) were observed in hyperoxygenated must in contrast to control must (caftaric acid 32.78 mg·L-1, coutaric acid 5.01 mg·L-1 and Catechin 4.45 mg·L-1). In the final wine, hydroxybenzoic acids were found in higher concentrations in the control variant (gallic acid 2.58 mg·L-1, protocatechuic acid 1.02 mg·L-1, vanillic acid 2.05 mg·L-1, syringic acid 2.10 mg·L-1) than in the hyperoxygenated variant (2.01 mg·L-1, 0.86 mg·L-1, 0.98 mg·L-1 and 1.50 mg·L-1 respectively). Higher concentrations of total flavanols (2 mg·L-1 in hyperoxygenated must and 21 mg·L-1 in control must; 7.5 mg·L-1 in hyperoxygenated wine and 19.8 mg·L-1 in control wine) and polyphenols (97 mg·L-1 in hyperoxygenated must and 249 mg·L-1 in control must; 171 mg·L-1 in hyperoxygenated wine and 240 mg·L-1 in control wine) were found in both the must and the control wine. A total of 24 volatiles were determined using gas chromatography mass spectrometry. Statistical differences were achieved for isobutyl alcohol (26.33 mg·L-1 in control wine and 32.84 mg·L-1 in hyperoxygenated wine), or 1-propanol (7.28 mg·L-1 in control wine and 8.51 mg·L-1 in hyperoxygenated wine), while esters such as isoamyl acetate (1534.41 µg·L-1 in control wine and 698.67 µg·L-1 in hyperoxygenated wine), 1-hexyl acetate (136.32 µg·L-1 in control wine and 71.67 µg·L-1 in hyperoxygenated wine) and isobutyl acetate (73.88 µg·L-1 in control wine and 37.27 µg·L-1 in hyperoxygenated wine) had a statistically lower concentration.

Origin of Wine Lignans.

Plant lignans possess several properties beneficial for human health and therefore, increasing their contents in foods and beverages is desirable. One of the lignan sources in human diet is wine. To elucidate the origin of lignans contained in wine, LC-MS was used to analyze resinol-related lignans in must, seeds, stems, and wine prepared using stainless steel tanks, oak barrels, and Qvevri (clay vessel). White wines aged in stainless steel tanks contained significantly lower amounts of lignan aglycones (20-60 µg/L) than red and Qvevri wines (300-500 µg/L). Generally, white wines aged in stainless steel tanks contained only low amounts of isolariciresinol and matairesinol. Qvevri wines and red wine aged in stainless steel tank contained up to five lignan compounds and in wine aged in oak barrel, six different lignans were identified. Consistently, only low concentration of isolariciresinol has been found in must, whereas more lignan compounds have been found in grape seeds (isolariciresinol, secoisolariciresinol, and pinoresinol) and stems (isolariciresinol and syringaresinol). Consequently, we conclude that lignan content in wine can be increased by maturation in contact with grape berries, seeds, or stems or with wood.

The Study of Antioxidant Components in Grape Seeds.

The paper deals with the study of antioxidant properties of extracts from vine seeds (Vitis vinifera L.) using spectrometric and chromatographic techniques. Ten vine varieties (Cerason, Laurot, Kofranka, Gewürztraminer, Hibernal, Blaufrankisch, Zweigeltrebe, Erilon, Palava, and Welschriesling) obtained from the years 2015, 2016, and 2017 were selected for the study. The antioxidant activity was determined spectrophotometrically using four fundamentally different methods; the content of total polyphenolic compounds was determined using the Folin-Ciocalteu method. In 2015, the content of 14 antioxidants (gallic acid, caffeic acid, coumaric acid, coutaric acid, ferulic acid, fertaric acid, trans-piceid, trans-piceatannol, rutin, quercetin-3-ß-d-glucoside, quercitrin, myricetin, catechin, and epicatechin) were studied. The results of the study show the high content of antioxidant components in grape seeds and the differences in content in individual varieties and in individual years.

Health Effects of Grape Seed and Skin Extracts and Their Influence on Biochemical Markers.

This review is focused on the study of the effects of grape seed and skin extract (GSSE) on human health. GSSE contains high concentrations of important polyphenolic substances with high biological activity. This review is a summary of studies that investigate the effects of GSSE on diabetes mellitus, cardiovascular disease and cancer, its neuroprotective effect, and its effects on the gastrointestinal tract and other health complications related to these diseases. The results of the studies confirm that the anti-inflammatory, antiapoptotic, and pro-proliferative effects of "Vitis vinifera L." seed extract reduce the level of oxidative stress and improve the overall lipid metabolism.

Capture of Fermentation Gas from Fermentation of Grape Must.

During alcoholic fermentation, a considerable amount of carbon dioxide (CO2) is produced, and the stream of CO2 can strip aromatic substances from the fermenting must. Aroma losses during fermentation can be significant and may lead to a reduction in wine quality. This study is focused on new fermentation gas capture technology. In the experiment, gas was captured during the fermentation of sauvignon blanc must. The concentration of individual volatile compounds in the fermentation gas was determined using gas chromatography, and the highest values were achieved by isoamyl acetate, isoamyl alcohol and ethyl decanoate. Ethyl dodecanoate achieved the lowest values of the investigated volatile substances. For sensory assessment, quantitative descriptive analysis (QDA) compared water carbonated with fermentation gas and water carbonated with commercial carbon dioxide for food purposes. Based on the results of this study, it can be concluded that the captured gas containing positive aromatic substances is suitable for the production of carbonated drinks in the food industry.