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Compositional and sensory characterization of red wine polymers
Nadine Wollmann1, Thomas Hofmann
1Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München , Lise-Meitner-Straße 34, 85354 Freising, Germany.
Journal of Agricultural and Food Chemistry
|February 8, 2013
Summary
High-molecular weight polymers in red wine, primarily procyanidins, were analyzed. Their structure and linkages were elucidated, revealing no significant impact of polymerization or galloylation on astringency.
Area of Science:
- Food Chemistry
- Polymer Science
- Enology
Background:
- Red wine's complex high-molecular weight polymers contribute significantly to astringency.
- Understanding the precise structure of these polymers is crucial for wine quality and sensory perception.
Purpose of the Study:
- To elucidate the detailed chemical structure of high-molecular weight polymers in red wine.
- To investigate the influence of polymer structure on astringency.
Main Methods:
- Isolation using ultrafiltration and gel adsorption chromatography.
- Compositional analysis via HPLC-MS/MS, HPLC-UV/vis, and ion chromatography after depolymerization.
- Sensory evaluation of individual polymer fractions.
Main Results:
- The polymer backbone is procyanidin-based with various extension and terminal units.
- Acetaldehyde and anthocyanins/pyranoanthocyanins form linkages within and to the procyanidin backbone.
- Polysaccharides are largely unlinked to procyanidins; esterification with organic and phenolic acids was observed.
- Neither the degree of polymerization nor galloylation significantly affected astringency perception.
Conclusions:
- Detailed structural features of red wine polymers were proposed.
- Astringency perception is not solely dependent on the degree of polymerization or galloylation.
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