Stabilizing effect of ascorbic acid on flavan-3-ols and dimeric procyanidins from cocoa.
J Agric Food Chem
; 51(3): 828-33, 2003 Jan 29.
Article
en En
| MEDLINE
| ID: mdl-12537465
ABSTRACT
Cocoa flavanols and procyanidins have numerous biological activities. It is known that (-)-epicatechin, (+)-catechin, epicatechin-(4beta-8)-epicatechin (dimer B2), and epicatechin-(4beta-6)-epicatechin (dimer B5) are unstable at physiologic pH, degrading almost completely within several hours, whereas they are relatively stable at pH 5.0. The present study investigated the effects of ascorbic and citric acid on the stability of monomers and dimers in simulated intestinal juice (pH 8.5) and in sodium phosphate buffer (pH 7.4). The addition of ascorbic acid to the incubation mixture significantly increased the stability of the monomers and dimers, whereas the addition of citric acid provided no protective effects. LC-MS showed that with the degradation of dimer B2 and dimer B5, doubly linked A-type dimers were formed. The present results, although not directly transferable to in vivo conditions, suggest that ascorbic acid may stabilize cocoa flavanols and procyanidins in the intestine where the pH is neutral, or alkaline, before absorption.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Ácido Ascórbico
/
Flavonoides
/
Cacao
/
Catequina
/
Biflavonoides
/
Proantocianidinas
Idioma:
En
Revista:
J Agric Food Chem
Año:
2003
Tipo del documento:
Article
País de afiliación:
Estados Unidos