Chardonnay white wine bottled with different oenological tannins: effect on colour traits, volatile composition and sensory attributes during shelf-life

Abstract

The use of oenological tannins during winemaking has been mostly studied for improving colour traits and stability on red wines. Their effectiveness mainly depends on the tannin composition, grape variety and winemaking approach [1]. However, few studies have been conducted for white varieties on the ability of exogenous tannins to preserve wines against oxidation and their influence on sensory properties [2,3]. Therefore, the aim of this research was to evaluate the effect of six tannin formulations (ellagic, gallic, acacia, quebracho, grape skin and grape seed tannins) on a ‘Chardonnay’ white wine during shelf-life. Each formulation was added at bottling at a dose allowing an equal increase in total polyphenols with respect to the non-added control. Standard parameters, colour characteristics, total polyphenols, antioxidant activity, volatile organic compounds (VOCs) and sensory properties were determined.

The antioxidant activity (DPPH method) decreased for most of treated wines during storage, except for both quebracho and grape seed tannins that showed a lower total polyphenols content after 9 months. After tannin addition and 1 month after bottling, an increased yellowish hue (higher absorbance at 420 nm) was observed in all wines, except for gallotannins. In the wines treated with ellagitannins or grape seed tannins, absorbance at 420 nm decreased after 9 months with small colour differences from control (ΔE*<2.5) whereas acacia and skin tannins contributed stronger to wine colour. Regarding sensory traits, there were some differences at 1 month after bottling, gallotannins and ellagitannins gave wines with higher aroma intensity (banana and pear being mostly cited descriptors), particularly compared to skin, quebracho and seed tannins (green apple discriminating the last two wines from the others). In agreement with aroma intensity, the best preservation of varietal VOCs was observed for gallotannnins-treated wines at 1 month after bottling, including terpenes and norisoprenoids. The wines treated with skin and seed tannins were more astringent but less bitter than control. After 9 months of shelf-life, the differences among the wines tested were reduced, gallotannins-added wines showing the lowest aroma intensity, whereas quebracho and seed tannins gave the most astringent wines. At this time, most of VOCs decreased for all tannin formulations but some esters and higher alcohols increased compared to control. These results highlight that oenological tannins can modulate aroma composition during wine shelf-life.

References

[1] Paissoni, M. A., Río Segade, S., Carrero-Carralero, C., Montanini, C., Giacosa, S., Rolle, L. (2020). Food Chem., 126633.

[2] Sonni, F., Chinnici, F., Natali, N., Riponi, C. (2011). Food Chem., 129, 1193–1200.

[3] Motta, S., Tirelli, A., Cravero, M. C., Guaita, M., Bosso, A. (2022). OENO One, 56–4, 221.