Studies on the polyphenolic composition and antioxidant properties of selected Hellenic red wines
2002
Arnous, A.
Aged red wines posses significantly different polyphenolic composition compared with young ones. This is due not only to the formation of polymeric compounds but also to oxidation, hydrolysis and other transformations that may occur in native grape phenolics during aging. Twenty seven representative selected aged wines (1998 vintage): 12 High Quality Appellation of Origin Wines (HQAOW) and 15 Regional Wines (RW) were examined for their Total Phenol (TP), Total Flavonol (TF) and Total Anthocyanin (TA) contents using spectrophotometry. An attempt was made to establish correlations with the wines antiradical activity (A sub(AR)), hydroxyl free radical scavenging activity (SA sub(HFR)), and reducing power (P sub(R)). The TP was found to vary from 1543 to 3606 mg L sup(-1) gallic acid equivelent (GAE) for HQAOW, and from 1217 to 3772 mg L sup(-1) GAE for RW. Total flavonol content ranged between 214.21 and 922.3 mg L sup(-1) catechin equivalent (CTE) for HQAOW and between 291.1 and 664.8 mg L sup(-1) CTE for RW.For HQAOW, total anthocyanins ranged between 79.4 and 363.1 mg L sup(-1), while they varied between 44.3 and 360.1 mg L sup(-1) for RW. Furthermore, anthocyanin composition was assayed using Reserved-Phase HPLC Chromatography (HPLE-DAD). The total anthocyanin content measured by HPLC (TA sub(HPLC)) was constantly lower than when measured using the spectral method; the ration ranged between 0.0057 and 0.560 for HQAOW and between 0.0 and 0.502 for RW. The antiradical activity (A sub(AR)) was evaluated using DPPH, and was found to vary between 0.79 and 1.48 and between 0.73 and 1.3 mM Trolox equivelants (TRE) for HQAOW and RW, respectively. The Hydroxyl Free Radical Scavenging Activity (SA sub(HFR)) was determined by the deoxyribose method, and a 28.2
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