IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Using 1H-NMR combined with chemometrics to discriminate the effect of different cuts and toasting of woods used for grape pomace distillate ageing

Using 1H-NMR combined with chemometrics to discriminate the effect of different cuts and toasting of woods used for grape pomace distillate ageing

Abstract

The purpose of this research study is to consider new solutions for distillate ageing, in alternative to conventional oak chips or barrels in particular sliced wood and peeled wood were compared to oak cubes, normally employed during both wine and distillate ageing. All three formats have been toasted using a “in lab” protocol at three different level of intensity: strongly toasted, lightly toasted and not toasted.
NMR spectroscopy was used to assess the differences, in and the chemical fingerprint among experimental distillates, aged using woods with different cuts and toasting levels.
NMR spectrometry is widely used in food analysis for metabolomic studies and for the evaluation of samples that have undergone different treatments. NMR allows to obtain a complex fingerprint spectrum characterised by the chemical species of the samples. The advantages of high resolution 1H-NMR are absolute reproducibility and laboratory-to-laboratory transferability, compared to other method currently used in food analysis. The region between 11 and 6 ppm of 1H-NMR spectra was chosen focussing on the range where main structural differences related to xylovolatile compounds, namely phenols, aldehydes and aromatic groups were present.
The obtained 1H-NMR data sets were firstly analysed by chemometric multivariate unsupervised methods, that showed a good separation between the control sample (i.e. distillates aged without oak) and all other samples, as well as between the different sample groups. In particular, principal components analysis (PCA), Anova-Simultaneous components analysis (ASCA) and hierarchical cluster analysis (HCA) were calculated and compared. This approach showed that samples refined with strongly, lightly or not toasted wood present a different molecular profile. A group separation was observed based on the wood cut type (i.e. sliced, peeled or cubes). Moreover, a non-negligible effect of the interaction between cut type and the toasting level was noticed.
Hence, the results confirmed the ageing process, that affects the chemical profile of grape pomace distillates, can be effectively monitored by NMR analysis. This provides a promising tool for distinguishing the different ageing conditions of spirits and assessing their quality

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Article

Authors

Portesi Chiara1, Mandrile Luisa1, Asproudi Andriani2, Bonello Federica2, Chiarabaglio Pier Mario3, Rosso Laura3 and Petrozziello Maurizio2

1INRiM – Istituto Nazionale di Ricerca Metrologica, Politecnico di Torino
2CREA, Research Centre for Viticulture and Enology
3CREA – Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria, Centro di Ricerca Foresta e Legno 

Contact the author

Keywords

Toasting process, wood chips, NMR, grape pomace distillate, chemometrics

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Current climate change in the Oplenac wine-growing district (Serbia)

Serbian autochthonous vine varieties Smederevka (for white wines) and Prokupac (for rosé and red wines) are the primary representatives of typical characteristics of wines and terroir of numerous wine-growing areas in Serbia. In the past, these varieties were the leading vine varieties, however, as the result of globalization of winemaking and the trend of consumption of wines from widely prevalent vine varieties, they were replaced by introduced international varieties. Smederevka and Prokupac vine varieties are characterized by later time of grape ripening, and relative sensitivity to low temperatures. Climate conditions can be a restrictive factor for production of high-quality grapes and wine and for the spatial spreading of these varieties in hilly continental wine-growing areas.
This paper focuses on the spatial analysis of changes of main climate parameters, in particular, analysis of viticultural bioclimatic indices that were determined for the purposes of viticulture zoning of wine-growing areas in the period 1961-2010, and those same parameters determined for the current, that is, referential climate period (1988-2017). Results of the research, that is, analysis of climate changes indicate that the majority of examined climate parameters in the Oplenac wine-growing district improved from the perspective of Smederevka and Prokupac vine varieties. These studies of climate conditions indicate that changes of analyzed climate parameters, that is, bioclimatic indices will be favorable for cultivation of varieties with later grape ripening times and those more sensitive to low temperatures, such as the autochthonous vine varieties Smederevka and Prokupac, therefore, it is recommended to producers to more actively plant vineyards with these varieties in the territory of the Oplenac wine-growing district.

Local ancient grapevine cultivars to face future viticulture

Among the different strategies to cope with the negative impacts of climate change on viticulture, the exploitation of genetic diversity is one of the most promising to adapt to new conditions and maintain wine production and quality. One of the biggest concerns in the context of climate change is to improve water use efficiency (WUE). In this way, the use of genotypes that present a better response to drought and high WUE is a key issue. In this work, physiological performance analysis was conducted to compare the water deficit stress (WDS) responses of local and widespread grapevines cultivars. Leaf gas exchange, water use efficiency (WUE) at different levels (leaf and long-term WUE (∆13C)), leaf osmotic adjustment and other water relations parameters were determined in plants under well-watered and WDS conditions alongside assessment of the levels of foliar hormones concentrations. Results denote that local cultivars displayed better physiological performance under WDS as compared to the widely-distributed ones. he results corroborate the hypothesis that better stomatal control allows increasing leaf WUE under drought as occurred in the local Callet cv.; but the minority local cultivar Escursac cv. showed high WUE under both treatments. In this case, high WUE can be related to maintaining higher photosynthetic activity under drought. The different mechanisms underlying the better performance under WDS and high WUE of minority local cultivars are discussed.

Mesoclimate impact on Tannat in the Atlantic terroir of Uruguay

The study of climate is relevant as an element conditioning the typicity of a product, its quality and sustainability over the years. The grapevine development and growth and the final grape and wine composition are closely related to temperature, while climate components vary at mesoscale according to topography and/or proximity to large bodies of water. The objective of this work is to assess the mesoclimate of the Atlantic region of Uruguay and to determine the effect of topography and the ocean on temperature and consequently on Tannat grapevine behavior.

Effect of the commercial inoculum of arbuscular mycorrhiza in the establishment of a commercial vineyard of the cultivar “Manto negro

The favorable effect of symbiosis with arbuscular mycorrhizal fungi (AMF) has been known and studied since the 60s. Nowadays, many companies took the chance to start promoting and selling commercial inoculants of AMF, in order to be used as biofertilizers and encourage sustainable biological agriculture. However, the positive effect of these commercial biofertilizers on plant growth is not always demonstrated, especially under field conditions. In this study, we used a commercial inoculum on newly planted grapevines of a local cultivar grafted on a common rootstock R110. We followed the physiological status of vines, growth and productivity and functional biodiversity of soil bacteria during the first and second years of 20 inoculated with commercial inoculum bases on Rhizophagus irregularis and Funeliformis mosseaeAMF at field planting time and 20 non-inoculated control plants. All the parameters measured showed a neutral to negative effect on plant growth and production. The inoculated plants always presented lower values of photosynthesis, growth and grape production, although in some cases the differences did not reach statistical significance. On the contrary, the inoculation supposed an increase of the bacterial functional diversity, although the differences were not statistically significant either. Several studies show that the effect of inoculation with AMF is context-dependent. The non-favorable effects are probably due to inoculation ineffectiveness under complex field conditions and/or that, under certain conditions, AMF presence may be a parasitic association. This puts into question the effectiveness of its application in the field. Therefore, it is recommended to only resort to this type of biofertilizer when the cultivation conditions require it (e.g., very low previous microbial diversity, foreseeable stress due to drought, salinity, or lack of nutrients) and not as a general fertilization practice.

Grapevine sugar concentration model in the Douro Superior, Portugal

Increasingly warm and dry climate conditions are challenging the viticulture and winemaking sector. Digital technologies and crop modelling bear the promise to provide practical answers to those challenges. As viticultural activities strongly depend on harvest date, its early prediction is particularly important, since the success of winemaking practices largely depends upon this key event, which should be based on an accurate and advanced plan of the annual cycle. Herein, we demonstrate the creation of modelling tools to assess grape ripeness, through sugar concentration monitoring. The study area, the Portuguese Côa valley wine region, represents an important terroir in the “Douro Superior” subregion. Two varieties (cv. Touriga Nacional and Touriga Franca) grown in five locations across the Côa Region were considered. Sugar accumulation in grapes, with concentrations between 170 and 230 g l-1, was used from 2014 to 2020 as an indicator of technological maturity conditioned by meteorological factors. The climatic time series were retrieved from the EU Copernicus Service, while sugar data were collected by a non-profit organization, ADVID, and by Sogrape, a leading wine company. The software for calibrating and validating this model framework was the Phenology Modeling Platform (PMP), version 5.5, using Sigmoid and growing degree-day (GDD) models for predictions. The performance was assessed through two metrics: Roots Mean Square Error (RMSE) and efficiency coefficient (EFF), while validation was undertaken using leave-one-out cross-validation. Our findings demonstrate that sugar content is mainly dependent on temperature and air humidity. The models achieved a performance of 0.65