The disappearance of the C-glycosidic ellagitannins over time can occur even in absence of oxygen and their disappearance rate seems to be affected by the presence of other ellagitannins in the media. The objective of this work was to study the influence of the presence of other ellagitannins and/or oxygen on the individual evolution of the main oak ellagitannins in simple model systems in order to understand their behaviours in more complex media, such as wine. In all the studied conditions, vescalagin disappeared faster than castalagin, highlighting its greater reactivity. Oxygen increased the individual disappearance rate, as also occurred when more than one type of ellagitannin was present, above all if the additional ellagitannin(s) contained the same conformation in C1 as vescalagin. Experimental data were fitted to a kinetic model considering both the oxygen-dependent and oxygen-independent reactions, making possible the comparison between individual compounds in different scenarios.
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http://dx.doi.org/10.1016/j.foodchem.2019.02.007 | DOI Listing |
Food Chem
January 2025
College of Enology, Northwest A&F University, Yangling 712100, China. Electronic address:
Ultrasound and ultrasound-coupled oak blocks techniques on the phenolic and astringency profiles of Petit Verdot wines were discussed in this study. The relationship between techniques at varying absorbed energy density (AED) gradients and astringency was revealed, elucidating potential molecular mechanisms regarding compound interactions. Ultrasound was found to promote phenolics degradation and condensed tannins maturation, while oak blocks improved ellagitannins release into wines, facilitating polycondensation reactions to form larger complexes.
View Article and Find Full Text PDFMolecules
September 2024
Instituto de Ciencias de la Vid y del Vino, Universidad de la Rioja, Gobierno de La Rioja y CSIC, Finca La Grajera, Ctra. De Burgos Km 6, 26007 Logroño, Spain.
The changes produced during the aging of wines in oak barrels are strongly dependent on the oak's geographical origin and aging time. This paper analyzes the effect of oak from four different geographical locations in four states in the USA, namely Missouri (Mo), Ohio (Oh), Kentucky (Kt), and Pennsylvania (Py), during 24 months of aging. Oak origin had a higher effect on the wine's aromatic composition than the polyphenolic one.
View Article and Find Full Text PDFFront Plant Sci
August 2024
Research Center of Deciduous Oaks, Beijing Forestry University, Beijing, China.
Hydrolyzable tannins (HTs) have garnered significant attention due to their proven beneficial effects in the clinical treatment of various diseases. The cupule of Chinese cork oak ( Blume) has been used as raw material of traditional medicine for centuries for its high content of HTs. Previous studies have identified UGT84A13 as a key enzyme in the HT biosynthesis pathway in , but the transcriptional regulation network of remains obscure.
View Article and Find Full Text PDFAntioxidants (Basel)
March 2024
UMR PAM 1517, Université Bourgogne Franche-Comté, Institut Agro, Université Bourgogne, INRAE, Institut Universitaire de la Vigne et du Vin-Jules Guyot, F-21000 Dijon, France.
New Phytol
June 2024
State Key Laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing, 100083, China.
Hydrolyzable tannins (HTs), predominant polyphenols in oaks, are widely used in grape wine aging, feed additives, and human healthcare. However, the limited availability of a high-quality reference genome of oaks greatly hampered the recognition of the mechanism of HT biosynthesis. Here, high-quality reference genomes of three Asian oak species (Quercus variabilis, Quercus aliena, and Quercus dentata) that have different HT contents were generated.
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