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This paper describes research conducted on the polyphenolic compounds found in wine and different parts of the grapevine. The research consisted of two experiments. In the first, extracts of polyphenols from the leaves, stems, skins and seeds were measured. In the second, these parts were macerated and left in the must during fermentation. For this experiment, the Souvignier gris wine grape variety was used. In both cases, 33 polyphenolic compounds were measured. These measurements were made using the liquid chromatography–mass spectrometry (LC-MS) method. Based on the results, the individual concentrations of all the polyphenolic compounds in different parts of the plant were measured. Addition of the individual parts of the grapevine to the must during fermentation was shown to increase the concentration of the individual polyphenols in the wine. It is therefore important not to forget the importance of the stems and the maceration of the grapes during the winemaking process.

The aim of the study was to determine the effect of controlled micro-oxygenation on the fermentation process of two types of white wine (ʻPinot Blancʼ and ʻPinot Grisʼ). The wine was micro-oxygenated during fermentation and maturation. During fermentation, the antioxidant activity was monitored by the DPPH method and the ammonia nitrogen and nitrogen content of the amino acids and the number of cells in 1 mL of fermenting must were also monitored. In micro-oxygenated wine, the growth of cell mass in the first third of the fermentation was recorded and showed an increase in ammonia nitrogen consumption compared to the control experiment. During fermentation, a slight increase in antioxidant activity was observed in the micro-oxygenated wine. For the aromatic profile measured by GC analysis, a higher content of aromatics, mainly esters, was observed in the micro-oxygenated wine. This was also present in the sensory evaluation.

This study deals with the determination of the content of both free and bound terpenes in berries and wine of the aromatic grapevine variety ‘Irsai Oliver’. Grapes were macerated in juice for different time intervals (viz. 0; 5; 12; 24 hours) and thereafter processed to wine. The objective was to map the dependence of some selected terpenes on the period of maceration. Using gas chromatography, some nine organic compounds were detected. Attention was paid to contents of linalool (3,7-dimethylokta-1,6-dien-3-ol), 2,6-dimetyl-3,7-octadiene-2,6-diol, hotrienol ([(5E)-3,7-dimethylocta-1,5,7-trien-3-yl] acetate), αterpineol (2-(4-Methyl-1-cyclohex-3-enyl)propan-2-ol), β-citronellol (3,7-Dimethyloct-6-en-1-ol), nerol ((Z)-3,7-dimethyl-2,6-octadien-1-ol), geraniol ((trans)-3,7-dimethyl-2,6-oktadien-1-ol) and epoxylinalool (2-(5-ethenyl-5-methyloxolan-2-yl)propan-2- ol): epoxylinalool 1 (trans-linalool oxide (furanoid) cis-linalool oxide (furanoid)) and epoxylinalool 2 (trans-linalool oxide (pyranoid) cis-linalool oxide (pyranoid)). Some basic wine parameters (alcohol, pH, sugars and total acids) were estimated as well. The terpene content in wine increased gradually with the period of maceration. The highest and the lowest amounts of terpenes were recorded after 24 hours of maceration and no maceration, respectively. The terpene glycosides content was higher than that of the aglycones. Linalool and 2,6-dimetyl-3,7-octadiene-2,6-diol were the most abundant terpenes.

This paper deals with a study of the inhibition of microorganisms occurring in grape must and wine, using silver in the form of nanoparticles and colloidal solution. Pure cultures of yeasts Saccharomyces cerevisiae and Brettanomyces bruxellensis, lactic acid bacteria Lactobacillus brevis, Pediococcus damnsosus and acetic acid bacteria Acetobacter aceti and Gluconobacter oxydans were used for the experiments. Attention was primarily focused on monitoring changes in carbohydrate processing, namely glucose, fructose, sucrose, maltose, mannitol, galactose, trehalose, and ß-glucosidase activity. These biochemical determinations have shown limitations in carbohydrate processing, particularly sucrose in yeasts, and fructose, glucose and sucrose in bacteria. The effects of silver have also been observed in natural microflora found in grape must from Chardonnay and Hibernal. Colloidal silver at concentrations 40, 70 and 100 ppm and silver nanoparticles at concentrations 70, 150 and 250 ppm were used for inhibition. A plate method was used to determine the number of viable colonies. With an increasing concentration of applied substances, the growth of both yeasts and bacteria was strongly inhibited, as indicated by the numbers of colonies cultivated from the must. Yeast growth was inhibited by the lowest concentration -- (70 ppm) by up to 72% and bacterial growth by up to 75.5%. [ABSTRACT FROM AUTHOR]

Nanotechnology is one of the most promising future technologies for the food industry. Some of its applications have already been introduced in analytical techniques and food packaging technologies. This review summarizes existing knowledge about the implementation of nanotechnology in wine laboratory procedures. The focus is mainly on recent advancements in the design and development of nanomaterial-based sensors for wine compounds analysis and assessing wine safety. Nanotechnological approaches could be useful in the wine production process, to simplify wine analysis methods, and to improve the quality and safety of the final product. [ABSTRACT FROM AUTHOR]

This study aimed to compare chemical properties, in terms of the content of volatile substances, antioxidant compounds, and antioxidant activity (AOA), in samples of fruit and grape wines. For this purpose, the following types of wine were selected, namely fruit wines (apple, strawberry, and elderberry) and grape wines (Müller-Thurgau, St. Lawrence Rosé, and Blue Portugal). Basic analyses of fruit and grape wines were conducted by using the ALPHA method and volatile substances in wines were determined by the GS/MC method. The antioxidant content and AOA were estimated by spectrophotometry, using two types of DPPH method. The results of the experiment showed that the highest values of antioxidant compounds (anthocyanins and flavanols) were found in the samples of Blue Portugal wine and elderberry wine. Significant differences were determined among the wines in antioxidant content, which may have been influenced by the production technology. The results showed that the alcohol content of the wines ranged from 10.99% to 19.49% vol. The highest alcohol content was measured in the elderberry wine samples and the lowest in those of the apple wine. The strawberry wine had the highest titratable acid content, which corresponded to a pH of 3.38. The lowest content was measured in the apple wine samples. Due to the higher acid content of the strawberry wine, a higher residual sugar level of 46.9 g.L-1 was obtained. We noted that the red fruit wines contained a higher proportion of valuable bioactive substances than white grape wines. Wines with superior sensory properties did not contain higher levels of antioxidants or higher AOA. The research results can provide a helpful reference for the widespread use of grape and fruit wines in medical, nutritional, and other fields. [ABSTRACT FROM AUTHOR]

The presented study is focused on the determination of the content of terpenic substances in grapes and subsequently produced a wine of Czech variety Pálava (the Czech Republic, wine region Morava), which is a protected landscape with long-term tradition and culture. The aim of this study was the analysis of the aromatic profile of the cultivar Pálava, which was fermented by the original yeast strains from the Moravian wine region. Larger amounts of flavoring substances occur in grapes as bound flavoring substances, most often in the form of glycosides. One of the basic groups of aromatic substances is monoterpenes. The content of twelve free and bound terpenic substances was measured by the GC-MS method, namely linalool, ho-trineol, a-terpeniol, β-citronellol, nerol, geraniol, furan linalool oxide 1, furan linalool oxide 2, nerol oxide, epoxylinalol 1, epoxylinalol 2 and 2,6-dimethyl-3,7-octadiene-2,6-diol. The results were statistically compared by using a simple descriptive statistical method and ANOVA method. We noted a difference between the content of free and bound terpenes was very significant (p ≤0.05). We found that using uncommercial yeasts could have an effect on the content of the volatile and terpenic compounds in wines. An important finding was that in fresh berry extracts there was a higher proportion of bound terpenes than free terpenes. The results have shown that the production technology of wine and the fermentation process has a clear impact on the content of the substances. [ABSTRACT FROM AUTHOR]