IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Unveiling the unknow aroma potential of Port wine fortification spirit taking advantage of the comprehensive two-dimensional gas chromatography

Unveiling the unknow aroma potential of Port wine fortification spirit taking advantage of the comprehensive two-dimensional gas chromatography

Abstract

Port wine is a fortified wine exclusively produced in the Douro Appellation (Portugal) under very specific conditions resulting from natural and human factors. Its intrinsic aroma characteristics are modulated upon a network of factors, such as the terroir, varieties and winemaking procedures that include a wide set of steps, namely the fortification with grape spirit (ca. 77% v/v ethanol). The fortification spirit comprises roughly one fifth of the total volume of this fortified wine, thus it is a potential contributor to the global quality of this beverage, including the aroma notes. Nonetheless, the information about the influence of the fortification spirit on the final aroma of Port wine, as well as the grape spirit volatile composition are extremely limited. Therefore, the main objective of this research is the optimization of an adequate methodology for the in-depth characterization of the fortification grape spirit volatile components, based on the use of advanced gas chromatography (GC×GC-ToFMS), combined with a solvent free solid phase microextraction technique (SPME). To fulfil this objective, the SPME experimental parameters (fiber coating, extraction temperature, and time, sample volume and dilution conditions) were optimized. Also, different column sets (first × second dimensions) were also tested to obtain the best chromatographic resolution and peak capacity. Firstly, the GC×GC-ToFMS experimental parameters were implemented, and the reversed phase column set (polar 1D × nonpolar 2D), with the same diameters in primary and secondary columns, presented advantages compared to the conventional column set (nonpolar 1D × polar 2D) regarding the analytes´ separation. Secondly, the SPME conditions that promoted the highest extraction efficiency were selected: 2.0 mL of spirit (diluted at 10% v/v ethanol) were extract with poly(dimethylsiloxane)/divinylbenzene fiber, at 40˚C, using 10 min of pre-equilibrium followed by 30 min of extraction. An exploratory application was performed using a set of grape spirits, which allowed the detection of hundreds of volatiles, from which 120 were putatively identified. This study adds further insights unveiling the complex nature of the grape spirits chemical volatile data, through the identification of compounds not yet determined in these matrices, some of which are associated with aroma notes highly valued in fortified wines. In addition, these volatile patterns seem to be useful to the spirits distinction/typing.

Acknowledgments:

This work was funded under the AD4PurePort – New range of Port wines, based on an innovative method of selecting fortification spirits), project 39956 – POCI-01-0247-FEDER-039956, supported by the COMPETE 2020 Operational Programme under the PORTUGAL 2020. Thanks are also due to FCT/MEC for the financial support LAQV-REQUIMTE (UIDB/50006/2020) through national funds and co-financed by the FEDER, with a PT2020 Partnership Agreement.

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Poster

Authors

Rocha Silvia1, Tavares Tiago1, Ribeiro Sónja1, Furtado Isabel2, Silva Ricardo2, Rogerson Frank S. S.2, Rudnitskaya Alisa3

1LAQV-REQUIMTE & Department of Chemistry, University of Aveiro
2Symington Family Estates
3CESAM & Department of Chemistry &, University of Aveiro

Contact the author

Keywords

Fortification spirit, Port wine, Volatile organic components, HS-SPME, GC×GC-ToFMS

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Effect of fertigation strategies to adapt PGI Côtes de Gascogne production to hot vintage

The development of fertigation could be a possible solution to adapt PGI Côtes de Gascogne (south-western France) wine production to climate change. The goal would be to limit the negative effects of water stress on yield performance expectation (around 15 tons per hectare) and to make the use of fertilizers more efficient. This study aimed to compare the effects of three strategies of water and minerals supply on grapes and wines qualities. Two fertigation practices were compared to a rainfed control which is the current standard of the local grape growing production. The fertilizers (nitrogen and potassium) were (i) fully brought by irrigation pipe during the season, (ii) partially brought by irrigation pipe and partially on the soil or (iii) fully brought on the soil at the beginning of the season for the non-irrigated control (local standard). The trial was run on cv. Colombard trained on spur pruned with vertical shoot positioning system on a sandy-silty-clay soil over the 2020 vintage which was particularly hot for the region. Moderate to strong water deficit appeared during the growing period of the berries and held on after veraison. Irrigation strategies allowed for maintaining grapevine without water deficit and being significantly different from the control water status. Grapevine with fully or partial fertigation strategies produced 25% more yield mainly due to the increase of the bunch weight. Also, the fully fertigation showed the best ratio between yield and maturity and brought 30% less of fertilizers (both nitrogen and potassium) than the two other strategies. Finally, the analysis of aromatic compounds in Colombard wines, varietal thiols family, showed the same level of concentrations for the 3 treatments, confirming that the yield performance did not impact the aromatic potential in this trial.

Organic recycled mulches in sustainable viticulture: assessment of spontaneous plants communities and weed coverage

In recent years, developing more efficient and sustainable viticulture management has been essential due to the impact of climate change in semiarid regions. For this reason, the use of recycled organic mulching (ROM) in the vineyard has become an interesting strategy to cope with water stress, isolated soil from extreme temperatures and improving soil humidity, control the presence of weeds and therefore reduce the inputs of herbicides and improve soil fertility. This work aimed to analyse the effect of three different organic mulches [straw (S), grape pruning debris (GPD) and spent mushroom compost (SMC)] and two traditional soil management techniques [herbicide (H) and interrow (IN)] on weed coverage and the spontaneous plant communities’ presence. Data sampling was collected throughout the vine vegetative cycle of 2021 in La Rioja, Spain. The different soil management techniques had a clear effect on weed coverage and his development during the vine vegetative cycle. SMC and H were the treatments with the highest and the lowest coverage percentage, respectively. IN had a delayed weed emergence at the beginning of the vine vegetative cycle, but finally it reached maximum values nearby SMC. GPD and S had similar effects on weed emergence, reaching 25-30% of the maximum coverage values. A total of 29 herbaceous species were identified during the vegetative cycle, some of them very isolated and occasional. Principal component analysis (PCAs) showed a good association between spontaneous species and treatments, furthermore, specific species-treatment associations were found. Moreover, three clear groups of herbaceous communities were identified by cluster analysis. This study provides interesting information about the effect of different alternative soil management on herbaceous plant coverage and weed species communities which could contribute to making more sustainable viticulture.

Adaptation to soil and climate through the choice of plant material

Choosing the rootstock, the scion variety and the training system best suited to the local soil and climate are the key elements for an economically sustainable production of wine. The choice of the rootstock/scion variety best adapted to the characteristics of the soil is essential but, by changing climatic conditions, ongoing climate change disrupts the fine-tuned local equilibrium. Higher temperatures induce shifts in developmental stages, with on the one hand increasing fears of spring frost damages and, on the other hand, ripening during the warmest periods in summer. Expected higher water demand and longer and more frequent drought events are also major concerns. The genetic control of the phenotypes, by genomic information but also by the epigenetic control of gene expression, offers a lot of opportunities for adapting the plant material to the future. For complex traits, genomic selection is also a promising method for predicting phenotypes. However, ecophysiological modelling is necessary to better anticipate the phenotypes in unexplored climatic conditions Genetic approaches applied on parameters of ecophysiological models rather than raw observed data are more than ever the basis for finding, or building, the ideal varieties of the future.

Grape berry size is a key factor in determining New Zealand Pinot noir wine composition

Making high quality but affordable Pinot noir (PN) wine is challenging in most terroirs and New Zealand’s (NZ) situation is no exception. To increase the probability of making highly typical PN wines producers choose to grow grapes in cool climates on lower fertility soils while adopting labour intensive practices. Stringent yield targets and higher input costs necessarily mean that PN wine cost is high, and profitability lower, in line-priced varietal wine ranges. To understand the reasons why higher yielding vines are perceived to produce wines of lower quality we have undertaken an extensive study of PN in NZ. Since 2018, we established a network of twelve trial sites in three NZ regions to find individual vines that produced acceptable commercial yields (above 2.5kg per vine) and wines of composition comparable to “Icon” labels. Approximately 20% of 660 grape lots (N = 135) were selected from within a narrow juice Total Soluble Solids (TSS) range and made into single vine wines under controlled conditions. Principal Component Analysis of the vine, berry, juice and wine parameters from three vintages found grape berry mass to be most effective clustering variable. As berry mass category decreased there was a systematic increase in the probability of higher berry red colour and total phenolics with a parallel increase in wine phenolics, changed aroma fraction and decreased juice amino acids. The influence of berry size on wine composition would appear stronger than the individual effects of vintage, region, vineyard or vine yield. Our observations support the hypothesis that it is possible to produce PN wines that fall within an “Icon” benchmark composition range at yields above 2.5kg per vine provided that the Leaf Area:Fruit Weight ratio is above 12cm2 per g, mean berry mass is below 1.2g and juice TSS is above 22°Brix.

The impact of sustainable management regimes on amino acid profiles in grape juice, grape skin flavonoids, and hydroxycinnamic acids

One of the biggest challenges of agriculture today is maintaining food safety and food quality while providing ecosystem services such as biodiversity conservation, pest and disease control, ensuring water quality and supply, and climate regulation. Organic farming was shown to promote biodiversity and carbon sequestration, and is therefore seen as one possibility of environmentally friendly production. Consumers expect organically grown crops to be free from chemical pesticides and mineral fertilizers and often presume that the quality of organically grown crops is different or higher compared to conventionally grown crops. Integrated, organic, and biodynamic viticulture were compared in a replicated field trial in Geisenheim, Germany (Vitis vinifera L. cv. Riesling). Amino acid profiles in juice, grape skin flavonoids, and hydroxycinnamic acids were monitored over three consecutive seasons beginning 7 years after conversion to organic and biodynamic viticulture, respectively. In addition, parameters such as soil nutrient status, yield, vigor, canopy temperature, and water stress were monitored to draw conclusions on reasons for the observed changes. Results revealed that the different sustainable management regimes highly differed in their amino acid profiles in juice and also in their skin flavonol content, whereas differences in the flavanol and hydroxycinnamic acid content were less pronounced. It is very likely that differences in nutrient status and yield determined amino acid profiles in juice, although all three systems showed similar amounts of mineralized nitrogen in the soil. Canopy structure and temperature in the bunch zone did not differ among treatments and therefore cannot account for the observed differences in favonols. A different light exposure of the bunches in the respective systems due to differences in vigor together with differences in berry size and a different water status of the vines might rather be responsible for the increase in flavonol content under organic and biodynamic viticulture.