AJEV
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am. J. Enol. Vitic. 43:2:134-138 (1992)
Copyright © 1992 by the American Society for Enology and Viticulture.
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Zapata, J. M.
Right arrow Articles by Barceló, A. R.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Zapata, J. M.
Right arrow Articles by Barceló, A. R.
Agricola
Right arrow Articles by Zapata, J. M.
Right arrow Articles by Barceló, A. R.

Oxidation of Natural Hydroxybenzoic Acids by Grapevine Peroxidases: Kinetic Characteristics and Substrate Specificity

J. M. Zapata 1, A. A. Calderón 1, R. Muñoz 1, and A. Ros Barceló 1

1 Department of Plant Biology (Plant Physiology), University of Murcia, Campus of Espinardo, E-30071 Murcia, Spain.

The oxidation of natural hydroxybenzoic acids by a cellular peroxidase (EC 1.11.1.7) fraction obtained from Vitis vinifera cv. Monastrell cell cultures has been studied. Of all the hydroxybenzoic acids present in Monastrell grapes, only protocatechuic (3,4-dihydroxybenzoic), vanillic (3-methoxy-4-hydroxybenzoic), and gallic (3,4,5-trihydroxy-benzoic) acids were substrates of this enzyme fraction, showing optimal pH values for the oxidation rate in the 3.0 to 5.0 range, p-Hydroxybenzoic acid and syringic (3,5-dimethoxy-4-hydroxybenzoic) acid were not substrates under the assay conditions. Apparent KM values for protocatechuic acid, vanillic acid, and gallic acid were 0.850, 0.120, and 1.080 mM, respectively. Using electrophoretic techniques, the differential reactivity of the peroxidase isoenzymes in this peroxidase fraction was shown against each hydroxybenzoic acid. This suggests a distinctive participation for each one of the isoenzymes in the several oxidative pathways of the hydroxybenzoic acids in Monastrell grapes.

Key words: enzymic browning, grapevine cell cultures, hydroxybenzoic acids, peroxidatic oxidation

Submitted on June 11, 1991






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1992 by the American Society for Enology and Viticulture.