IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 The use of microwaves during the maceration of Cabernet Sauvignon wines for improving their chromatic characteristics

The use of microwaves during the maceration of Cabernet Sauvignon wines for improving their chromatic characteristics

Abstract

The use of new technologies such as microwaves (MW) arose in recent years as an efficient alternative to reduce the use of sulfur dioxide (SO2) and as a method for improving wines in terms of color and aroma [1, 2]. MW (non-ionizing electromagnetic waves with frequencies between 300 MHz and 300 GHz) have been widely applied in the food industry in order to reduce processing time and favor food preservation. The MW cause the migration of ions and dipoles generate frictional forces increasing the temperature. This thermal energy can break bonds between compounds, being able to favor the breakage of the cell wall of the grape skin. This would favor the extraction of compounds of interest, allowing wineries to reduce maceration time and increasing their production capacity. In this context, our work focuses on studying the capacity of MW to favor the extraction of phenolic compounds from red grapes of the Cabernet Sauvignon variety in order to obtain wines of high color quality with short maceration times.For this, the chromatic parameters and phenolic composition of wines elaborated with MW treated grapes were studied and compared with a control vinification. This test was carried out using two different maceration times: 72 hours and 7 days. The MW treatment in all cases consisted of applications lasting 12 min at 700 W using a domestic oven avoiding temperature increases above 40ºC. All assays were performed in triplicate and wines were analyzed by spectrophotometry and high-performance liquid chromatography at the time of bottling.The results obtained showed an increase in the content of phenolic compounds and color intensity (CI) in the wines obtained from grapes treated with microwaves respect to their controls for both maceration times (12% and 15% increase in CI, respectively). No significant differences were observed for none of the chromatic parameters studied between the wine obtained after a MW treatment and macerated for 72 hours and the control wine with a four-day longer maceration, being of special interest the CI and the total polyphenol index (TPI) (CI: 16.16 vs 17.18 and TPI: 45.22 vs 47.05, respectively).For this reason, this study shows the possibility of reducing the maceration time without losing quality in the wines obtained when MW are used.

References

[1] Muñoz García, R.; Oliver Simancas, R.; Díaz-Maroto, M.C.; Alañón Pardo, M.E.; Pérez-Coello, M.S. (2021). Foods, 10, 1164.
[2] Carew, A.L.; Gill,W.; Close, D.C.; Dambergs, R.G. (2014). Am. J. Enol. Vitic., 65, 401–406.

DOI:

Publication date: June 24, 2022

Issue: IVAS 2022

Type: Poster

Authors

Pérez-Porras Paula1, Bautista-Ortín Ana Belén1, Munoz-García Raquel2, Díaz-Maroto Mª Consuelo2, Pérez-Coello Mª Soledad2 and Gómez-Plaza Encarna1

1Department of Food Science and Technology, Faculty of Veterinary Science, University of Murcia.
2Area of Food Technology, Faculty of Chemical Sciences and Technologies, Regional Institute for Applied Scientific Research (IRICA), University of Castilla-La Mancha, 13071 Ciudad Real, Spain

Contact the author

Keywords

Microwave, Chromatics, Polyphenols, Maceration, Wine

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Terroir traceability in grapes, musts and wine: results of research on Gewürztraminer and Sauvignon Blanc grape varieties in northern Italy

In the study of terroir, a separate analysis of its many component factors can be of great help in accurately identifying a vineyard’s natural elements that impact wine quality and typicity. This research used a dedicated pluri-disciplinary approach to investigate the ecological characteristics, including geology and geographical features, of 14 vineyards that produce Gewürztraminer and Sauvignon Blanc cultivars in the alpine Alto Adige DOC wine region. Both the geopedological method using Vineyards Geological Identity (VGI) and the new Solar Radiaton Identity (SRI) topoclimatic classification method were used to provide analytical measurements and qualitative/quantitative characterisations. In addition, wide-ranging targeted and untargeted oenological and chemical analyses were carried out on grapes, musts and wines to correlate the soils’ geomineral and physical conditions with the biochemical properties of their fruits and wines. The research identified strong correlations between vineyard geo-identity and wine biofingerprint, confirming a mineral traceability of strontium rubidium ratio and some minerals distinctive to the local geology, such as K, Ca, Ag, Ba and Mn.  The study also discovered that particular geomineral and physical soil conditions of the studied vineyards are related to the different amount of amino acids, primary varietal aromas and polyphenols found in grapes, musts and wines. The research confirmed that winemaking technologies support oenological quality, although in some cases, human practices can overpower certain characteristic elements in wine, erasing the typical imprint left by the vineyards’ natural terroir, which becomes less traceable. Terroir abiotic ecological factors and vineyard identity can be classified in detail using the new VGI and SRI analysis methods to discover interrelationships between geo-pedological and topoclimatic conditions that impact wine quality. These methods are also helpful in identifying which ecological elements are exclusive to a particular vineyard or wine sub-region.

Phenological characterization of a wide range of Vitis Vinifera varieties

In order to study the impact of climate change on Bordeaux grape varieties and to assess the adaptation capacities of candidates to the grape varieties of this wine region to the new climatic conditions, an experimental block design composed of 52 grape varieties was set up in 2009 at the INRAE Bordeaux Aquitaine center. Among the many parameters studied, the three main phenological stages of the vine (budburst, flowering and veraison) have been closely monitored since 2012. Observations for each year, stage and variety were carried out on four independent replicates. Precocity indices have been calculated from the data obtained over the 2012-2021 period (Barbeau et al. 1998). This work allowed to group the phenological behaviour of the grapevine varieties, not only based on the timing of the subsequent developmental stages, but also on the overall precocity of the cycle and the total length of the cycle between budburst and veraison. Results regarding the variability observed among the different grape varieties for these phenological stages are presented as heat maps.

Effects of organic mulches on the soil environment and yield of grapevine

Farming management practices aiming at conserving soil moisture have been developed in arid and semiarid-areas facing water scarcity problems. Organic mulching is an effective method to manipulate the crop-growing microclimate increasing crop yield by controlling soil temperature, and retaining soil moisture by reducing soil evaporation. In this sense, the effectiveness of different organic mulching materials (straw mulch and grapevine pruning debris) applied within the row of a vineyard was evaluated on the soil and on the vine in a Tempranillo vineyard located in La Rioja (Spain). Organic mulches were compared with a traditional bare soil management technique (based on the use of herbicides to avoid weed incidence). Mulching coverages favourably influenced the soil water retention throughout all the grapevine vegetative cycle. However, the soil-moisture variation was not the same under different mulching materials, being the straw mulch (SM) the one that retained more water in comparison with grapevine pruning debris (GPD) based-cover. The changes of soil moisture in the upper surface layer (0–10 cm) were highly dynamic, probably due to water vapour fluxes across the soil-atmospheric interface. However, both, SM and GPD reduced these fluctuations as compared with bare soils. A similar trend occurred with soil temperature. Both organic mulches altered soil temperature in comparison with bare soil by reducing soil temperature in summer and raising it in winter. Moreover, the same buffering effect for the temperature on the covered soil also remains in the deeper layers. To conclude, we could see that organic mulching had a positive impact on soil-moisture storage and soil temperature and the extent of this effect depends on the type of mulching materials. These changes led to higher rates of photosynthesis and stomatal conductivity compared to bare soils, also favouring crop growth and grape yields.

Teasing apart terroir: the influence of management style on native yeast communities within Oregon wineries and vineyards

Newer sequencing technologies have allowed for the addition of microbes to the story of terroir. The same environmental factors that influence the phenotypic expression of a crop also shape the composition of the microbial communities found on that crop. For fermented goods, such as wine, that microbial community ultimately influences the organoleptic properties of the final product that is delivered to customers. Recent studies have begun to study the biogeography of wine-associated microbes within different growing regions, finding that communities are distinct across landscapes. Despite this new knowledge, there are still many questions about what factors drive these differences. Our goal was to quantify differences in yeast communities due to management style between seven pairs of conventional and biodynamic vineyards (14 in total) throughout Oregon, USA. We wanted to answer the following questions: 1) are yeast communities distinct between biodynamic vineyards and conventional vineyards? 2) are these differences consistent across a large geographic region? 3) can differences in yeast communities be tied to differences in metabolite profiles of the bottled wine? To collect our data we took soil, bark, leaf, and grape samples from within each vineyard from five different vines of pinot noir. We also collected must and a 10º brix sample from each winery. Using these samples, we performed 18S amplicon sequencing to identify the yeast present. We then used metabolomics to characterize the organoleptic compounds present in the bottled wine from the blocks the year that we sampled. We are actively in the process of analysing our data from this study.

Bioclimatic shifts and land use options for Viticulture in Portugal

Land use, plays a relevant role in the climatic system. It endows means for agriculture practices thus contributing to the food supply. Since climate and land are closely intertwined through multiple interface processes, climate change may lead to significant impacts in land use. In this study, 1-km observational gridded datasets are used to assess changes in the Köppen–Geiger and Worldwide Bioclimatic (WBCS)