510 research outputs found

    Supercritical Extraction from Vinification Residues: Fatty Acids, α-Tocopherol, and Phenolic Compounds in the Oil Seeds from Different Varieties of Grape

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    Supercritical fluid extraction has been widely employed in the extraction of high purity substances. In this study, we used the technology to obtain oil from seeds from a variety of grapes, from vinification residues generated in the Southern region of the state of Rio Grande do Sul, Brazil. This work encompasses three varieties of Vitis vinifera (Moscato Giallo, Merlot, and Cabernet Sauvignon) and two of Vitis labrusca (Bordô e Isabel), harvested in 2005 and 2006. We obtained the highest oil content from Bordô (15.40%) in 2005 and from Merlot (14.66%), 2006. The biggest concentration of palmitic, stearic, and linoleic acids was observed in Bordô, 2005, and in Bordô, Merlot, and Moscato Giallo, 2006. Bordô showed the highest concentration of oleic acid and α-tocopherol in both seasons too. For the equivalent of procyanidins, we did not notice significant difference among the varieties from the 2005 harvest. In 2006, both varieties Isabel and Cabernet Sauvignon showed a value slightly lower than the other varieties. The concentration of total phenolics was higher in Bordô and Cabernet Sauvignon. The presence of these substances is related to several important pharmacological properties and might be an alternative to conventional processes to obtain these bioactives

    Determination of bioactive amines in tropical wines produced at Brazilian's Northeast.

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    The wine production in the region of the Sub-middle São Francisco river Valley has started there are few years ago.The region has a climate variability that allows to obtain two or three harvests per year, which influences significantly the composition of the grapes. This work aimed to evaluate the amount of amines present in white and red tropical wines produced in the Northeast of Brazil. The winemaking was done by the traditional method. After stabilizing the wines were bottled and then analyzed for the determination of the amines putrescine, spermidine and spermine, by thin layer chromatography (TLC). The harvests were in June (harvest I) and November (harvest II) 2009. The results showed that the edaphoclimatic conditions of the two harvests had significant influence (p> 0.05) on bioactive amines concentration, with high values for red wines. In addition, tropical wines from Sub-middle São Francisco river Valley showed adequate correlation between bioactive amines as compared to other wines in the world

    Characterization of aromatic profiles in brazilian tropical wines determined by gas chromatography and multivariate statistical analysis.

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    Tropical wines have been produced in Thailand, India, Venezuela and mainly in Northeastem Brazil. In Brazil, this activity started twenty-five years ago and has been studied only in the last years. In this Brazilian Area, between 8_90 parallel of the South Hemisphere, it is possible to have two or three harvests per year due to the high temperatures (annual average temperature of 26 "C), high luminosity and use of irrigation. Analytical composition of grapes and wines can vary strongly according to harvest date into a year, (wines elaborated in the first or second semester). The aim of this work was to determine metabolic fingerprints of white and red wines from two vintages of 2009, according to their aromatic profile, using gas chromatographyand multivariate statistical analyses. Wines were elaborated by traditional methods, in stainless steel tanks of 200 L, by controlling fermentations temperature for red and white wines and using antioxidants. After stabilization and bottling, wines were analyzed in triplicate using gas chromatography with flame ionization detecto r (OC-FID). PCA multivariate statistical analysis was applied on aromatic compounds data to discriminate between wine type and month of winemaking, and different clustering were formed. White and red tropical wines presented different aromatic compound concentrations; higher alcohols were more efficient to separate wine samples than volatile esters

    Phenolic composition and antioxidant activity in sparkling wines: Modulation by the ageing on lees

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    AbstractSparkling wines (SW) have a special biological ageing on lees that is performed using two distinct methods: in the bottle (Champenoise) or in isobaric tanks (Charmat method). The objective of this study was to compare the levels of phenolic compounds, β-Glucosidase and antioxidant activity during the ageing on lees, in samples of SW produced at industrial scale by both methods. The β-Glucosidase activity has been constant over time, showing a close relationship with all the polyphenols studied (resveratrol, piceid, tyrosol, gallic, caffeic and ferulic acids), which were affected by the sur lie time. With these cross-reactions, the biological properties of the SW were also modulated. The results showed that the long period of ageing decreased the antioxidant potential in all samples. This work demonstrates that the sur lie is more important than the production method itself, due to its ability to modulate the necessary changes to achieve the specific objective
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