Assessing the potential of fermentative skin contact in white winemaking on phenolic, colour, and sensory traits

Abstract

Fermentative maceration in white wine production, involving extended contact with grape skins and seeds, has gained interest in recent years [1]. The impact of this winemaking technique on wine composition and sensory properties remains underexplored. This study investigates the influence of maceration time on the basic parameters, phenolic composition, colour, and sensory attributes of white wines from two Italian autochthonous varieties, ‘Arneis’ and ‘Erbaluce’. Laboratory-scale fermentations were conducted at 18 °C with maceration lasting 0 (control), 2, 7, and 14 days. After maceration, wines were analysed and subjected to oxygenation via air saturation followed by 1-month storage to evaluate oxygen exposure effects. Phenolic compounds were monitored using spectrophotometric and HPLC analyses, focusing on (+)-catechin, (–)-epicatechin, quercetin, quercetin-3-glucoside, condensed tannins, and polymeric flavanol structure. Wine sensory analysis was performed using the Rate-All-That-Apply (RATA) technique [2].

Wine colour was significantly influenced, with increased absorbance at 420 nm in wines subjected to prolonged maceration and air saturation. Total phenolic content increased with maceration time, as previously found [3], doubling after 2 days and quadrupling after 14 days compared to the control, with no significant variations post-oxygenation. The concentrations of (+)-catechin and (–)-epicatechin increased with maceration, while monomeric flavan-3-ols were not detected in control wines. Wine condensed tannins were found only in 7 and 14-day macerated samples, reaching 513 mg/L in Arneis and 708 mg/L in Erbaluce wines for the longest maceration time tested. Although the mean degree of polymerization (mDP) was unaffected by maceration, galloylation significantly increased in Arneis wines with longer maceration time. At the end of fermentation, free acetaldehyde levels were highest in control wines, decreasing with maceration and further declining after air saturation. Oxygenation notably increased condensed tannins (+20.3% on average) accompanied by a decrease in monomeric flavan-3-ols, thus suggesting the possible formation of polymeric flavanols [4] but no mDP differences were found. Sensory evaluation confirmed that longer maceration increased colour intensity, hue, and astringency, while a decline in white and yellow pulp fruit aroma descriptors was observed. These findings improve the understanding of maceration impact on white wine phenolics and sensory traits, offering insights for optimizing maceration to achieve desired wine profiles.

References

[1] Buican, B. C., Colibaba, L. C., Luchian, C. E., Kallithraka, S., & Cotea, V. V. (2023). Agriculture, 13(9), 1750.

[2] Ares, G., Bruzzone, F., Vidal, L., Cadena, R.S., Giménez, A., Pineau, B., Hunter, D.C., Paisley, A.G., & Jaeger, S.R. (2014). Food Quality and Preference, 36, 87-95.

[3] Aleixandre-Tudo, J. L., Weightman, C., Panzeri, V., Nieuwoudt, H. H., & Du Toit, W. J. (2015). South African Journal of Enology and Viticulture, 36(3), 366-377.

[4] Cucciniello, R., Tomasini, M., Russo, A., Falivene, L., Gambuti, A., & Forino, M. (2023). Food Chemistry, 426, 136556.