Exploring the use of high-power ultrasound in white and rosé winemaking

Abstract

Since the approval in 2019 of the use of high-power ultrasound (US) in winemaking to support extractive processes from grape to must [1], the study of this technology in red winemaking has increased significantly, with laboratory and semi-industrial scale studies [2]. Ultrasound in winemaking can be applied as a continuous pretreatment of crushed grapes, the improvement of extraction being the main interest of its use, favouring a more intense wine colour profile [3]. However, the use of this technology in white and rosé winemaking, which has been less studied, shows great promise for reducing or eliminating pre-fermentative maceration processes without losing the high organoleptic quality of the wines [4]. This possibility would not only reduce production time and cost but also ensure that the wines most susceptible to oxidation (those with a high hydrocynnamic acid and flavanol content) suffer less risk of being affected.

High-power ultrasound application essays were conducted on a semi-industrial scale and using a frequency of 30 kHz on crushed grape from Monastrell (for rosé wine) and Viognier (for white wine) varieties, studying the effect on vinifications carried out without pre-fermentation maceration (CPD), with 8 hours of pre-fermentation maceration (CM) and with US application after crushing the grapes and just before pressing (US). These trials showed that the rosé wine made with US had a profile rich in terpenes and norisoprenoids, compounds linked to the floral profile observed in the sensory analysis, as well as red fruit aroma. It also had higher colour intensity, higher presence of phenolic compounds and of polysaccharides rich in arabinose and galactose (PRAG) and homogalacturonans (HL). In white wine, in addition to these compounds, a higher presence of rhamnogalacturonans type II (RG-II) was observed, together with a stronger varietal aromatic profile (increasing the concentration of α-terpineol and linalool in free form) intensified thanks to the extraction benefited by the US, even without any prefermentative contact time, which resulted in raised scores in attributes such as floral, peach and sweet apricot.

Thus, the use of high-power ultrasound not only results in the possibility of reducing the winemaking time without loss of quality, but also in the possible improvement of the colour and varietal aromatic profile of the wines produced.

References

[1] Organisation Internationale de la Vigne et du Vin (OIV). (2019). Oeno 616-2019. International code of oenological practices.

[2] Kumar, Y., Marangon, M., Mayr Marangon, C. (2023). Beverages, 9, 30.

[3] Zhang, Q. A., Zheng, H., Lin, J., Nie, G., Fan, X., & García-Martín, J. F. (2023). Ultrason. Sonochem., 95, 106384.

[4] Gómez-Plaza, E., Pérez-Prieto, L.J., Pérez-Porras, P., Bautista-Ortín, A.B. (2021). Chapter 7 in White Wine Technology (Elsevier).