Macrowine 2021
IVES 9 IVES Conference Series 9 Validation of a high-throughput method for the quantification of volatile carbonyl compounds in wine and its use in accelerated ageing experiments

Validation of a high-throughput method for the quantification of volatile carbonyl compounds in wine and its use in accelerated ageing experiments

Abstract

AIM: the aim of this study was the optimization and validation of a robust and comprehensive method for the determination of volatile carbonyl compounds (VCCs) in wines. The protocol was then applied to determine the evolution of VCCs in wines after accelerated ageing. VCCs are widely present in foods and beverages; their formation is due to chemical reactions and biological processes where oxygen plays a key role [1]. However, many of these are side transformations that highly affect the final aroma. The total package oxygen is usually negligible in bottled wines. However, that amount combined with temperature and light, can modify the oxidative status with a consequent loss in varietal aroma and an increase in off-flavors and defects [2]. At the same time, several carbonyls are related to pleasant scents so the winemaking of many oxidized wines like Madeira, Port, Vin Santo is tailored to emphasize their productions. We expect that a high-throughput method for the measure of the concentration of carbonyls could be added as a new quality control tool for the evaluation of a complete fermentation, correct winemaking style, and proper bottling and storage.

METHODS: Various white wines (cv. Gewürztraminer) and red wines (cv. Teroldego) were submitted to accelerated-ageing process. All bottles were opened under inert atmosphere inside a sealed hood and submitted to the accelerated-ageing procedure, according to Oliveira et. al. [3]. The extraction procedure was based on the protocol purposed by Moreira et. al. [4], upgraded with a fully automated sample preparation performed by a CTC-PAL3 autosampler. The sample was transferred from the 2 mL vial (kept at 5°C) to a 20 mL vial and then spiked with internal standard (IS) and derivatizing agent (PFBHA) solutions. After a 7 minutes derivatization at 45°C, the SPME extraction is performed at 40°C for 20 minutes. Finally, the fiber desorption takes place at 250°C for 4 min. GC-MS analysis was carried out using a TSQ Quantum XLS Ultra Triple Quadrupole GC-MS/MS using MRM acquisition. Calibration curves were acquired in matrix using a commercial white wine treated with activated carbon to remove odor active compounds. Acetone d6, 4-methyl-4-penten-2-one d10, Octanal d16 and 4-fluorobenzaldehyde were used as IS. As many as 56 VCCs were the analytes under investigation.

RESULTS: all compounds showed a good linearity spanning from approximately 0.1 to 50 µg/L (R2>0.99). Intra-day and 5 days repeatability showed an RSD

DOI:

Publication date: September 14, 2021

Issue: Macrowine 2021

Type: Article

Authors

Maurizio Piergiovanni

University of Trento, Centre Agriculture, Food, Environment (C3A), San Michele all’Adige, Italy,Silvia, CARLIN, Research and Innovation Centre, Food Quality and Nutrition Department, Fondazione Edmund Mach, San Michele all’Adige, Italy  Cesare, LOTTI, Research and Innovation Centre, Food Quality and Nutrition Department, Fondazione Edmund Mach, San Michele all’Adige, Italy.  Fulvio, MATTIVI, University of Trento, Centre Agriculture, Food, Environment (C3A), San Michele all’Adige, Italy.

Contact the author

Keywords

carbonyls, oxidation, ageing, accelerated ageing, solid-phase micro extraction, automatization, oxygen, off-flavors

Citation

Related articles…

Influence of agronomic practices in soil water content in mid-mountain vineyards

In the context of LIFE project MIDMACC (LIFE18 CCA/ES/001099), several pilots have been installed in vineyards in mid mountain areas of Catalonia (NE Spain) to test well stablished agronomic practices to increase the adaptation of Mediterranean mid mountain to climate change. Soil water content (SWC) at three different depths (15, 30 and 45cm) was measured in continuum from August 2020. One pilot (WC) included a well-established green cover (GC), a new GC (NC) and a conventional soil management (CM, tilling+herbicides). NC presented an intermediate state between WC and CM, responding similarly to CM in autumn but quickly reaching similar SWC to WC, then following the same evolution till next spring, with CM presenting lower values along autumn and winter. Then vegetation activation decreased SWC in all plots, (much slower in CM, lacking GC). Sensibility to spring rains is again intermediate for NC, which joins SWC evolution of CM by the end of spring till next autumn. It is expected that NC will resemble WC more and more as its GC develops. In the pilot combining vine training (VSP vs Gobelet) and hillside management (slope vs terrace), no clear pattern could be related with these conditions. However, both terraces seem to be more sensitive to spring rains. A third pilot included new vineyards (7 and 1 year old). In the new vineyard (N), higher canopy development, a spontaneous green cover and row straw resulted in a slower SWC dynamic, not so sensitive to rains but conserving more soil water in spring and most of summer, even with presumably a higher water extraction by vines. In the newest vineyard (VN) the deepest sensor is still sensitive to rain events all over the year and SWC is always highest at this depth, revealing small water capture by vines.

First step in the preparation of a soil map of the Protected Designation of Origin Valdepeñas (Central, Spain)

This work is a first step to make a map of vineyard soils. The characterization of the soils of the Protected Designation of Origin (D.P.O.) Valdepeñas will allow to group the studied profiles according to their physico-chemical characteristics and the concentrations of most relevant chemical elements. 90 soil profiles were analysed throughout the territory and the soils were sampled and described according to FAO (2006) and classified according to and Soil Taxonomy (2014). All samples were air dried, sieved and some physico-chemical parameters were determined following standard protocols. Also, major and trace elements were analysed by X-ray fluorescence. The statistically study was made using the SPSS program. Trend maps were made using the ArcGIS program. The studied soils have the following average properties: pH, 8.3; electrical conductivity, 0,20 dS/m (low); clay, 18.8% (medium) and CaCO3, 17.1% (high). In the study for the major elements. The major elements of these soils are Si, followed by Ca and Al, with an average content of 203.7 g/kg, 105.5 g/kg and 74.0 g/kg respectively. On the other hand, 27 trace elements have been studied. Of all of them, it can be highlighted the average values of Ba (361.8 mg/kg), Sr (129.3 mg/kg), Rb (83.4 mg/kg), V (74.2 mg/kg) and Ce (70.6 mg/kg). Ba, V and Ce values are higher and the values of Sr and Rb are lower to those found in the literature. The discriminant analysis shows a percentage of grouping of 91%. The content of chemical elements together with the physico-chemical characteristics allows grouping the soils in 4 group according to their order in the classification to Soil Taxonomy; due to the importance of the Calcisols in Castilla-La Mancha, it has been decided to establish them as their own group even if they do not appear in Soil Taxonomy classification.

Impact of yeast derivatives to increase the phenolic maturity and aroma intensity of wine

Using viticultural and enological techniques to increase aromatics in white wine is a prized yet challenging technique for commercial wine producers. Equally difficult are challenges encountered in hastening phenolic maturity and thereby increasing color intensity in red wines. The ability to alter organoleptic and visual properties of wines plays a decisive role in vintages in which grapes are not able to reach full maturity, which is seen increasingly more often as a result of climate change. A new, yeast-based product on the viticultural market may give the opportunity to increase sensory properties of finished wines. Manufacturer packaging claims these yeast derivatives intensify wine aromas of white grape varieties, as well as improve phenolic ripeness of red varieties, but the effects of this application have been little researched until now. The current study applied the yeast derivative, according to the manufacture’s instructions, to the leaves of both neutral and aromatic white wine varieties, as well as on structured red wine varieties. Chemical parameters and volatile aromatics were analyzed in grape musts and finished wines, and all wines were subjected to sensory analysis by a tasting panel. Collective results of all analyses showed that the application of the yeast derivative in the vineyard showed no effect across all varieties examined, and did not intensify white wine aromatics, nor improve phenolic ripeness and color intensity in red wine.

Sustaining wine identity through intra-varietal diversification

With contemporary climate change, cultivated Vitis vinifera L. is at risk as climate is a critical component in defining ecologically fitted plant materiel. While winegrowers can draw on the rich diversity among grapevine varieties to limit expected impacts (Morales-Castilla et al., 2020), replacing a signature variety that has created a sense of local distinctiveness may lead to several challenges. In order to sustain wine identity in uncertain climate outcomes, the study of intra-varietal diversity is important to reflect the adaptive and evolutionary potential of current cultivated varieties. The aim of this ongoing study is to understand to what extent can intra-varietal diversity be a climate change adaptation solution. With a focus on early (Sauvignon blanc, Riesling, Grolleau, Pinot noir) to moderate late (Chenin, Petit Verdot, Cabernet franc) ripening varieties, data was collected for flowering and veraison for the various studied accessions (from conservatory plots) and clones. For these phenological growing stages, heat requirements were established using nearby weather stations (adapted from the GFV model, Parker et al., 2013) and model performances were verified. Climate change projections were then integrated to predict the future behaviour of the intra-varietal diversity. Study findings highlight the strong phenotypic diversity of studied varieties and the importance of diversification to enhance climate change resilience. While model performances may require improvements, this study is the first step towards quantifying heat requirements of different clones and how they can provide adaptation solutions for winegrowers to sustain local wine identity in a global changing climate. As genetic diversity is an ongoing process through point mutations and epigenetic adaptations, perspective work is to explore clonal data from a wide variety of geographic locations.

Impact of climate change on the viticultural climate of the Protected Designation of Origin “Jumilla” (SE Spain)

Protected Designation of Origin “Jumilla” (PDO Jumilla) is located in the Spanish provinces of Albacete and Murcia, in the South-eastern part of the Iberian Peninsula, where most of the models predict a severe impact of climate change in next decades. PDO Jumilla covers an area of 247,054 hectares, of which more than 22,000 hectares