Oxygen exposure during red wine fermentation modifies tannin reactivity with poly-l-proline.
Food Chem
; 297: 124923, 2019 Nov 01.
Article
em En
| MEDLINE
| ID: mdl-31253258
ABSTRACT
Red wines injected with nitrogen or oxygen during fermentation were used to identify the effect of gas exposure on tannin structure and reactivity with poly-l-proline. Tannin was purified from wine after fermentation and after three years of bottle storage. Tannin from nitrogen-treated wine had a lower percentage of galloylation and were less pigmented than tannin from oxygen-exposed wine. Self-aggregation of tannin was measured by nanoparticle tracking analysis and a larger particle size was observed for the oxidized treatment. The interaction of tannin and poly-l-proline was measured by isothermal titration calorimetry, and involved more hydrogen bonding than hydrophobic interactions in the case of nitrogen-treated wine tannin. Conversely, oxidized tannin was more hydrophobic and the association with poly-l-proline was entropy-driven due to a change of solvation. The results show meaningful changes in the structure and reactivity of tannin as a result of oxygen exposure during fermentation, which may impact astringency perception.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oxigênio
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Peptídeos
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Taninos
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Vinho
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article