Influence of phenolic composition and antioxidant properties on the ageing potential of Syrah red wines measured by accelerated ageing tests.

Abstract

Red wine ageing impacts its chemical and sensory characteristics such as colour, astringency and aromas evolution. Wine ageing involves many chemicals and physico-chemical reactions. Oxygen has an important role in these evolutions, especially during bottle ageing. It is known that wine composition and its antioxidant capacity are correlated to its ability to undergo with oxygen exposure [1]. A high oxygen exposure can affect wine quality by the formation of undesirable oxidative volatile compounds such as acetaldehyde [2]. Thus, ageing capacity is an important factor for wine quality and is related to extent of oxidation with ageing [3].
The aim of this study was to characterize the influence of phenolic composition and antioxidant properties on the ageing capacity of 14 Syrah red wines, measured by accelerated ageing tests (AATs) based on oxygen consumption rate recently developed (thermal test at 60°C, enzymatic test with laccase and chemical test with H2O2) [4]. To achieve this, different parameters were measured such as anthocyanins and flavanols contents, antioxidant capacity, voltammetric behaviour, colour parameters and free SO2 level. Statistical analysis was performed to correlate the results of the ATTs with the initial phenolic composition and antioxidant properties of Syrah red wines. 
High correlations were obtained between the initial phenolic composition and antioxidant properties of the samples. Principal component analysis (PCA) was used to classify wines and discriminate them into three groups depending on their composition as well as their antioxidant properties. The results showed significant differences between the three studied ATTs, these results revealing specific mechanisms for each accelerated ageing condition. Partial least squares (PLS) regression was carried out in order to establish a model that can predict the AATs based on their different parameters studied. These models predicted with success the AATs (R2 > 0.93 for all of them) and showed the influence of specific phenolic compounds in the models.

References

[1] Ferreira, V., Carrascon, V., Bueno, M., Ugliano, M., & Fernandez-Zurbano, P. (2015).Oxygen Consumption by Red Wines. Part I : Consumption Rates, Relationship with Chemical Composition, and Role of SO2. Journal of Agricultural and Food Chemistry, 63(51), 10928-10937. https://doi.org/10.1021/acs.jafc.5b02988
[2] Oliveira, C. M., Ferreira, A. C. S., De Freitas, V., & Silva, A. M. S. (2011). Oxidation mechanisms occurring in wines. Food Research International, 44(5), 1115-1126. https://doi.org/10.1016/j.foodres.2011.03.050
[3] Waterhouse, A. L., & Miao, Y. (2021). Can Chemical Analysis Predict Wine Aging Capacity? Foods, 10(3), 654. https://doi.org/10.3390/foods10030654
[4] Deshaies, S., Cazals, G., Enjalbal, C., Constantin, T., Garcia, F., Mouls, L., & Saucier, C. (2020). Red Wine Oxidation : Accelerated Ageing Tests, Possible Reaction Mechanisms and Application to Syrah Red Wines. Antioxidants, 9, 663. https://doi.org/10.3390/antiox9080663