 IVES 9 IVES Conference Series 9 Macrowine 9 Macrowine 2021 9 Grapevine diversity and viticultural practices for sustainable grape growing 9 Exploring the effect of ripening rates on the composition of aroma and phenolic compounds in Cabernet-Sauvignon wines

Exploring the effect of ripening rates on the composition of aroma and phenolic compounds in Cabernet-Sauvignon wines

Abstract

AIM: The study of cultural practices to delay ripening and the characterization of their effect on wine composition is important in the mitigation of accelerated ripening caused by higher temperatures and frequent water stress events. The desynchronization between sugar accumulation and anthocyanins and organic acids during advanced ripening reported in previous studies frequently results in sub-optimal phenolic and aromatic maturity at the targeted sugar levels for winemaking. In this study, the effect of different rates of ripening on the chemistry of Cabernet Sauvignon wines was studied to explore if delayed ripening would result in higher quality wines.

METHODS: Fruit sugar accumulation rates were manipulated by means of crop load manipulation treatments and late season irrigation. Fruit was harvested at 26 °Brix and submitted to small-lot research winemaking. The basic chemistry and the composition of phenolic and aroma compounds were analyzed in the final wines.

RESULTS: The vineyard treatments returned three kinetics of sugar accumulation. A faster sugar accumulation (1 week earlier) was obtained by reducing crop load while a combination of crop removal and late season irrigation delayed ripening (2 weeks later) compared to untreated vines. Such effects of crop load and late season irrigation were already reported previously. In the final wines, there were little or no changes in the basic chemistry in response to the ripening rate. Crop load affected mainly the profile of wine aroma compounds, including both grape-derived and fermentation-derived compounds. On the other hand, an increase of irrigation late in the season led to an increase in phenolic compound levels, resulting in improved color and mouthfeel characteristics. Ripening was delayed by the interaction of cluster thinning and late season irrigation, which in turn led to higher concentrations of both volatile and phenolic compounds and further improvement of wine quality. In response to a slower sugar accumulation, an improvement of primary quality indicators of grape quality, such as lower green compounds and higher anthocyanins, translated into higher wine quality. Similar effects on these wine components were already observed in studies in which ripening was delayed by other means.

CONCLUSION

This study provides further confirmation that delayed ripening is beneficial to improve wine quality in late-ripening varieties. Amelioration of accelerated ripening is especially critical in warm and dry viticulture regions with long seasons, while the treatments investigated may not be necessary nor result in the same outcomes in cool wine regions. It was also shown that crop load and late season irrigation have a specific effect on aroma and phenolic compounds respectively, which deserves to be further explored in future studies.

DOI:

Publication date: September 2, 2021

Issue: Macrowine 2021

Type: Article

Authors

Pietro Previtali

The University of Adelaide and Australian Research Council Training Centre for Innovative Wine Production,Nick DOKOOZLIAN, E. & J. Gallo Winery and Australian Research Council Training Centre for Innovative Wine Production Luis SANCHEZ, E. & J. Gallo Winery Bruce PAN, E. & J. Gallo Winery Kerry WILKINSON, The University of Adelaide and Australian Research Council Training Centre for Innovative Wine Production Christopher FORD, The University of Adelaide and Australian Research Council Training Centre for Innovative Wine Production

Contact the author

Keywords

aroma compounds; delayed ripening; phenolic compounds; ripening rates; wine metabolites

Citation

Climate change projections to support the transition to climate-smart viticulture

The Earth’s system is undergoing major changes through a wide range of spatial and temporal scales as a response to growing anthropogenic radiative forcing, which is pushing the whole system far beyond its natural variability. Sources of greenhouse gases largely exceed their sinks, thus leading to a strengthened greenhouse effect. More energy is thereby being supplied to the system, with inevitable shifts in climatic patterns and weather regimes. Over the last decades, these modifications have been manifested in the full statistical distributions of the atmospheric variables, with dramatic changes in the frequency and intensity of extremes. Natural hazards, such as severe droughts, floods, forest fires, or heatwaves, are being triggered by extreme atmospheric events worldwide, thus threatening human activities. Viticultculture is not only exposed to changing climates but is also highly vulnerable, as grapevine phenology and physiological development are strongly controlled by atmospheric conditions. Therefore, the assessment of climate change projections for a given region is critical for climate change adaptation and risk reduction in viticulture. By adopting timely and suitable measures, the future sustainability and resiliency of the sector can be fostered. Climate-grapevine chain modelling is an essential tool for better planning and management. However, the accuracy of the resulting projections is limited by many uncertainties that must be duly taken into account when transferring knowledge to stakeholders and decision-makers. Climate-smart viticulture will comprise ensembles of locally tuned strategies, envisioning both adaptation and mitigation, assisted by emerging technologies and decision-support systems.

From vineyard to bottle. Rationalizing grape compositional drivers of the expression of valpolicella aroma ‘terroir’

AIM: Valpolicella is a renowned Italian wine-producing region (Paronetto, 1981). Wines produced in its different sub-regions are anecdotally believed to be aromatically different, although there is no systematic study addressing the chemical bases of such diversity

The terroir of winter hardiness: a three year investigation of spatial variation in winter hardiness, water status, yield, and berry composition of riesling in the niagara region using geomatic technologies

Grapevine winter hardiness is a key factor in vineyard success in many cool climate wine regions. Winter hardiness may be governed by several factors in addition to extreme weather conditions – e.g. soil factors (texture, chemical composition, moisture, drainage), vine water status, and yield– that are unique to each site.

Assessing the effect of oak derived aromas on mouthfeel perception in Chardonnay wine

Mouthfeel is an important quality parameter for Chardonnay wines, particularly those aged in oak. While research on mouthfeel has traditionally focused on the impact of non-aromatic compounds, the role of aroma compounds has largely been over looked. However, in wine as well as other food interactions between retronasal aroma and mouthfeel have been noted. The goal of this research was to investigate the impact of wine aroma on the perception of mouthfeel. Because of the importance of oak aging in the development of Chardonnay mouthfeel, the impact of oak aromas on perceived mouthfeel was explored. Aroma compounds associated with oak (ethyl palmitate, eugenol, furfural, isoeugenol, syringaldehyde, vanillin and whiskey lactone) were added to two different Chardonnay wines; one with no oak influence and one fermented in neutral oak. Low and high concentrations of the compounds were added based on concentrations typically found in barrel aged Chardonnay wine.

D-wines: use of LC-MS metabolomic space to discriminate italian mono-varietal red wines

Studying wine metabolome through multiple targeted methods is complicated and limitative; since grapes, yeasts, bacteria, oxygen, enological techniques and wine aging collaborate to deliver one of the richest metabolomic fingerprint.