Publications by authors named "Olga Laureano"

The major areas of the world where viticulture is practiced enjoy temperate or cool temperature climates. When wine grapes are grown in tropical regions, edaphoclimatic factors result in distinct grape quality attributes, and production techniques also require significant adjustment. The objective of this study was to characterize the chemical compositions, in particular of phenolic compounds, of Syrah grapes grown in two location in northeast Brazil - these are also at widely different altitudes.

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Background: Obtaining two or more successive annual vintages from the same vineyard is characteristic of regions with a tropical climate, such as the Submédio of the São Francisco Valley, Brazil. The present study aimed to characterize the chemical composition of grapes in four production cycles (i.e.

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Article Synopsis
  • Grapevines (Vitis vinifera) produce phenylpropanoid compounds like flavonoids and stilbenes that act as antioxidants and help the plant deal with stress.
  • Under sulfur deficiency (-S), these plants showed an increase in certain flavonoids and stilbenes, particularly anthocyanins and trans-resveratrol, while chlorophyll levels decreased.
  • The study highlights how V. vinifera reallocates resources towards phenylpropanoid biosynthesis in response to sulfur deficiency, suggesting a strategy to cope with oxidative stress caused by nutrient shortages.
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The phenolic composition of skins and seeds from Vitis vinifera L. cv. Carménère and Cabernet Sauvignon grapes during ripening was evaluated by high-performance liquid chromatography-diode array detection and spectrophotometric analysis.

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The monomeric, oligomeric, and polymeric flavan-3-ol composition of wines, grape seeds, and skins from Vitis vinifera L. cv. Graciano, Tempranillo, and Cabernet Sauvignon has been studied using (1) fractionation by polyamide column chromatography followed by HPLC/ESI-MS analysis, (2) fractionation on C(18) Sep-Pak cartridges followed by reaction with vanillin and acid-catalyzed degradation in the presence of toluene-alpha-thiol (thiolysis).

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