Influence of must composition on phenolic oxidation kinetics
Abstract
White grape musts with added sulphur dioxide, ascorbic acid, glutathione, copper or flavanols were prepared and oxidised using known amounts of oxygen. Sulphur dioxide and ascorbic acid delayed caffeoyltartaric acid oxidation, 2-S-glutathionyl caffeoyltartaric acid (GRP) formation and browning development. The glutathione content determined the quantity of GRP formed; browning was prevented when all the caffeoyltartaric acid quinones generated by enzymic oxidation could be trapped as GRP. Cupric ions, which lower the concentration of available glutathione, enhanced must browning. Coupled oxidation of flavanols by the caffeoyltartaric acid quinones also led to increased discoloration.
- Publication:
-
Journal of the Science of Food and Agriculture
- Pub Date:
- January 1991
- DOI:
- 10.1002/jsfa.2740570107
- Bibcode:
- 1991JSFA...57...55R