Changes in the Phenolic Composition and Antioxidant Activity of Pinotage, Cabernet Sauvignon, Chardonnay and Chenin blanc Wines During Bottle Ageing

Abstract

The effect of bottle ageing on the antioxidant activity of Pinotage, Cabernet Sauvignon, Chardonnay and Chenin blanc wines, using the 2,2'-azino-di-(3-ethylbenzothialozine-sulphonic acid) radical cation (ABTS•+) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH 0 ) scavenging assays, was determined. Storage at 0°C, 15°C or 30°C for a period of 12 months resulted in a significant (p ~ 0.05) decrease in both the total antioxidant activity (TAAAnTs and TAAoPPH) and the total phenol content of the wines. The antioxidant potency of the total phenols of most of the wines, which is a ratio of antioxidant activity to the total phenol content, also decreased. The total anthocyanins in the red wines decreased significantly (p ~ 0.05) over 12 months except for storage at 0°C, while the flavanol content of the Pinotage, Cabernet Sauvignon and Chardonnay wines increased up to nine months storage with a subsequent decrease to 12 months. The flavonol content of all the wines decreased, while only minor changes in their hydroxycinnamate content were observed during the storage period. Understanding the complexity of these reactions may provide clues for stabilising especially red wines to preserve the antioxidant activity without losing the beneficial effects of colouring and flavour development during bottle ageing.The ability of wines and other foods to prevent free radical-mediated diseases has been investigated recently (Halliwell & Gutteridge, 1990;Davies, 1995;Leake, 1998). The possible health-promoting properties of wine are related in part to phenolic compounds and their ability to act as antioxidants (Kinsella et al., 1993). In view of the greater health awareness among the public in terms of their diet, the antioxidant content or antioxidant potential may become a factor in determining the acceptability and marketability of wine and other foodstuffs. More information is, however, needed on the effect of technological factors and storage conditions on the antioxidant parameters of wine prior to consumption. Various technological factors relating to vineyard and vinification practices (Hurtado et al., 1997;Pellegrini et al., 2000), as well as the effect of cultivar (De Beer et al., 2003), were shown to alter the phenolic content and antioxidant activity of red and white wines.Bottle ageing is important for the improvement of red wine quality (Somers & Pocock, 1990). For white wine it can contribute to quality defects such as non-enzymatic browning and over-maturation, although some white wines may derive shortterm benefit from the development of a characteristic bottle bouquet (Marais & Pool, 1980). Conflicting reports regarding the effect of ageing on the antioxidant activity of red wines have been *Corresponding author: E-mail address: joubertl@arc.agric.za published. Manzocco et al. (1998) and Okuda et al. (2002) reported a decrease in 2,2-diphenyl-1-picrylhydrazyl radical (DPPH 0 ) scavenging activity for older wines based on the scavenging rate and total radical scavenging activity, respectively. Larrauri et al. (...

Characterisation of Pinotage Wine During Maturation on Different Oak Products

“…Maturation caused a slight decrease in the total phenol content of the Pinotage wine for some of the treatments, similar to what has been found for Pinotage and Cabernet Sauvignon wines subjected to bottle ageing for one year (De Beer et al, 2005). Many individual phenolic compounds also decreased during maturation.…”

“…Although no detrimental effect on the TAC of the wine was observed in the present study, maturation over a longer period or in the presence of higher oxygen concentrations may have a negative impact on the wine TAC. The maturation of Pinotage and Cabernet Sauvignon wines that were not matured in oak resulted in decreased wine TAC over a one-year bottle-ageing period (De Beer et al, 2005).…”

“…A change in TAC during maturation is most likely to be negative. Some reactions of phenolic compounds during pre-bottling maturation are expected to be similar to those that occur during bottle maturation, which has been shown to decrease the TAC of Pinotage and Cabernet Sauvignon wines (De Beer et al, 2005). In order to produce wines with optimal TAC, the effect of oak maturation and oxygenation on their TAC should be taken into account.…”

Do Differences in the Colour and Phenolic Composition of Young Shiraz Wines Reflect During Ageing?

“…Values are means of triplicate repeats; different letters indicate significant differences at p < 0.05. As monomeric anthocyanins become polymerised their concentration decreases, while that of polymeric pigments increases during wine ageing (De Beer et al, 2005). The 2013 results show the same trend as in the previous year, with the R treatment having significantly higher colour density than the other treatments (Table 2).…”

“…The polymeric pigments showed no differences between the treatments after MLF, but after six months of ageing the polymeric pigment concentrations of the wines from all the treatments had increased as the anthocyanins polymerised ( Table 2), with that of the VSP and R treatments being significantly higher. This could have been due to higher tannin concentrations in these treatments, leading to polymerisation with anthocyanins and therefore an increase in polymeric pigments (De Beer et al, 2005). However, trends in colour and pigmented phenols observed in the young wines were often still reflected after ageing.…”