Phenolic extraction and dissolved oxygen concentration during red wines fermentations with Airmixig M.I.™
During red wine fermentation, the extraction of phenolics compounds and sufficient oxygen provision are critical for wine quality [1,2]. In this trial, we aimed at evaluating the kinetics of phenolic extraction and dissolved oxygen during red wine fermentations using the airmixing system. Twenty lots of red grape musts were fermented in 300.000 L tanks, equipped with airmixing, using two injection regimes (i.e., high and low intensity, and high and low daily frequency). An oxygen analyzer was introduced into the tanks in order to record the concentration of dissolved oxygen over time. Additionally, juice/wine samples were taken at days 0, 2, 4, and 6 as to evaluate their chemical composition with an emphasis on phenolics. Our results showed clear differences in dissolved oxygen depending on the aeration regime employed. Like so, phenolic composition varied between samples, but less differences were observed among aerations regimes. The highest intensity and frequency of air injections produced the highest peaks of oxygen dilution, but not the highest increase in total phenolics, anthocyanins, short polymeric pigments, and tannin concentration. Differences in phenolic compounds among treatments were mostly mediated by temperature changes during fermentation. However, these variations tend to equilibrate by the end of the fermentation. Based on these results, more research is being conducted to keep characterizing the extraction kinetics, color, and phenolic evolution of red wines fermented with air injections.
Acknowledgements: Thanks to ANID-Fondecyt grants 1190301 and 1231484 for financing this study, and to Viña Santa Carolina for allowing us to work at their winery. PPM also thanks ANID for her doctoral scholarship, “Beca de doctorado nacional”.
1) Day MP. et al. (2021) Aeration of Vitis vinifera Shiraz fermentation and its effect on wine chemical composition and sensory attributes. Aust. J. Grape Wine Res., 27: 360-377, DOI 10.1111/ajgw.12490
2) Gambuti A. et al. (2018) Evolution of Sangiovese wines with varied tannin and anthocyanin ratios during oxidative aging. Front. Chem., 6 (march): 1-11, DOI 10.3389/fchem.2018.00063
Issue: ICGWS 2023
1Facultad de Ciencias Agrarias, Universidad de Talca, Chile. Av. Lircay s/n, Talca, Chile. 346000