Monitoring the effect of micro-oxygenation before malolactic fermantation on South African Pinotage red wine with different colour and phenolic analysis
Date
2012
Journal Title
Journal ISSN
Volume Title
Publisher
South African Society for Enology and Viticulture
Abstract
The use of micro-oxygenation and its effect on the quality of the red wine varietal, Pinotage, is largely
unknown. The influence of adding different oxygen dosages before malolactic fermentation on the
phenolic composition and colour stabilisation of wine made from Pinotage was studied, and the
suitability of certain spectrophotometric and RP-HPLC analyses to determine these changes were
assessed in tanks of commercial lengths. Total oxygen dosages of 0 mg/L, 16 mg/L and 32 mg/L were
applied, after which the wines underwent malolactic fermentation and maturation in the same tanks for
two additional months. Decreases in anthocyanin concentration showed a strong inversely proportional
correlation with increasing polymeric pigment concentration. This suggests that the addition of
oxygen contributed to the early stabilisation of wine colour in Pinotage red wine. Overall, tannin
concentrations were not significantly influenced by the oxygen treatments, although lower levels were
observed in wines treated with oxygen. An important finding of the study was that there appeared to be
little difference in the colour and phenolic composition of the wines between the 16 mg/L and 32 mg/L
oxygen treatments. Good correlations were found between certain spectrophotometric techniques and
the RP-HPLC analysis used to study changes induced by micro-oxygenation (total anthocyanins, total
phenols). The colour and phenolic composition of Pinotage wine can be influenced before malolactic
fermentation by micro-oxygenation. Some spectrophotometric phenolic analyses showed the same
tendencies as observed with RP-HPLC (anthocyanins, monomeric flavan-3-ols, tannins), indicating their
suitability to follow phenolic and colour changes induced by micro-oxygenation in Pinotage red wine.
Description
CITATION: Geldenhuys, L., Oberholster, A. & Du Toit, W. J. 2012. Monitoring the effect of micro-oxygenation before malolactic fermantation on South African Pinotage red wine with different colour and phenolic analysis. South African Journal of Enology and Viticulture, 33(2):150-160, doi:10.21548/33-2-1115.
The original publication is available at http://www.journals.ac.za/index.php/sajev
The original publication is available at http://www.journals.ac.za/index.php/sajev
Keywords
Tannins, Wine and wine making, Micro-oxygenation, Red wines -- South Africa, Pinotage
Citation
Geldenhuys, L., Oberholster, A. & Du Toit, W. J. 2012. Monitoring the effect of micro-oxygenation before malolactic fermantation on South African Pinotage red wine with different colour and phenolic analysis. South African Journal of Enology and Viticulture, 33(2):150-160, doi:10.21548/33-2-1115.