Abstract: In order to explore the effect of storage time on phenolic components of red wine, red wine from Cabernet Sauvignon was sealed in stainless steel tanks for 3 years, and variations in phenolic components and total antioxidant capability during aging period were detected. The results indicated that total phenols did not exhibit an obvious change after storage for 1 year; in addition, total flavonoids and total flavanols in red wine reached up to their respective maximum values, and then exhibited a gradual decrease with extended aging time. However, total anthocyanins revealed a gradual decrease. During the storage period, gallic acid gradually replaced salicylic acid as the major hydroxybenzoic acid, and the total content exhibited a gradual downward trend but remained higher than hydroxycinnamic acid, another phenolic acid. Among all the identified phenols, the content of catechin was the highest. Most of the identified phenols reached their peaks after 1 year of aging, followed by a progressive decline. During the whole aging period, the relative content of flavonoids was increased, while the relative content of non-flavonoids exhibited an opposite change. DPPH scavenging capability and cupric ion reducing anti- oxidant capacity (CUPRAC) reached their maximum values after aging for 1 year, and then declined gradually; in contrast, hydroxyl radical scavenging capability exhibited a gradual decrease throughout the aging period. In terms of DPPH scavenging capability and CUPRAC, hydroxycinnamic acid had stronger antioxidant activity than hydroxybenzoic acid; on the other hand, salicylic acid, quercetin and ferulic acid had strong hydroxyl radical scavenging capability.

Key words: dry red wine, sealing in stainless steel tanks, phenolic compounds, antioxidant activity