Effect of ozone treatments in wine production on colour traits, volatile composition, and sensory characteristics of young and short-term aged white wines

Abstract

The main aim of WiSSaTech project (PRIN P2022LXY3A),supported by the Italian Ministero dell’Università e della Ricerca and European Union-NextGenerationEU, is to investigate eco-friendly and safe alternatives to sulphur dioxide (SO₂) in wine production. Three treatments were compared on two Italian white wines produced from grapes cv. Fiano and Vermentino: ozone treatment of grapes and cellar equipment either alone (O₃) [1] or following the Purovino® method (PV) [2], and conventional use of SO₂. Colour characteristics (CIELab coordinates [3]), total polyphenols (absorbance at 280 nm and Folin-Ciocalteu method [4]), antioxidant activity (DPPH, ABTS, FRAP, and CUPRAC methods [4]), and volatile organic compounds (HS-SPME-GC-MS method [5]) were determined. Moreover, sensory analysis was conducted using descriptive analysis [6]. All analyses were carried out on the obtained wines (T0), after accelerated aging at 35 °C for one week (T1),and after six months of conventional aging at 18 °C (T6).

Results showed that the antioxidant activity for Vermentino was higher in SO₂-added wines at T0, T1, and T6 followed by O₃-treated samples whereas total polyphenols were higher in the latter. Similar trends were observed for the antioxidant activity in Fiano wines, showing lower values for the PV treatment. Ozone treatments also influenced the VOCs profile. For Fiano, total free VOCs concentration decreased in PV and O₃ wines at T0 compared to SO₂ trial. Particularly, esters and acids diminished for PV treatment whereas benzenoids, terpenes, and norisoprenoids increased. However, benzenoids and terpenes decreased for O₃-treated samples, as also occurred at T1 and T6, whereas norisoprenoids increased. All increasing trends were confirmed at T6. For Vermentino wines, higher concentrations of benzenoids, terpenes, and norisoprenoids were also obtained for both PV and O₃ treatmentsat T0 and T1, but differences were observed between them at T6 leading to ahigher total VOCs concentration in PV-treated samples. Sensory analysis revealed higher fruity and floral notes (green apple descriptor at T1, pear, yellow pulp fruit, pineapple at T6) in O₃ samples for Vermentino and Fiano, probably due to a higher citation of oxidation/reduction faults evidenced in the other wines. Higher sensory perceived colour hue in PV samples was in agreement with instrumental parameters (lower L* and higher b*), showing the highest colour differences (ΔE*) with SO₂ treatments, that were perceived more green at the three sampling stages.

References

[1] Modesti, M., Macaluso, M.,Taglieri, I.,Bellincontro, A., Sanmartin, C. (2021). Foods, 10, 2934.

[2] Mencarelli, F., Catelli, C. (2013). Process for the Treatment and the Winemaking of Grapes. Italy Patent No. PCT/IB2012/000036.

[3] OIV (2016). Compendium of International Methods of Analysis of Wines and Musts. Organisation Internationale de la Vigne et du Vin, Paris, France.

[4] Vignault, A., González-Centeno, M. R., Pascual, O., Gombau, J., et al. (2018). Food Chem., 268, 210–219.

[5] Slaghenaufi, D., Ugliano, M. (2018). Front. Chem., 6, 66.

[6] Lawless, H. T., Heymann, H. (2010). Sensory Evaluation of Food: Principles and Practices. Springer, New York.