 IVES 9 IVES Conference Series 9 Insights from selected ion flow tube mass spectrometry (SIFT-MS) and chemometrics applied to the quick discrimination of grapevine varieties

Insights from selected ion flow tube mass spectrometry (SIFT-MS) and chemometrics applied to the quick discrimination of grapevine varieties

Abstract

Selected Ion Flow Tube Mass Spectrometry (SIFT-MS) is an innovative analytical method based on soft chemical ionization to analyze thecomposition in volatile compounds of a gas phase. In this research, we propose a quick way to access the aromatic potential of grape varieties through a scan of their volatilome by SIFT-MS and chemometrics approaches. During 3 sampling campaigns carried out in September 2020, we collected berries from 21 grapes varieties planted in a germplasm collection. For each variety, three replicate samples of 50g were gently crushed and put in 1L Schott bottles that were directly connected to a SIFT-MS equipment to analyse the headspace. Analytes injected in the SIFT-MS were ionized with 3 different reagent ions (H3O+, O2+. and NO+) to generate increased molecular fragmentation data (2). M/z data/ratios were first analysed with XlStats software (Addinsoft, Paris, France) using a one-way ANOVA treatment to determine the ions that enabled to discriminate the grape varieties. Then based on these discriminating ions, Principal Component Analysis (PCAs) were constructed and Hierarchical Clustering Analysis (HCA) ensued to create similarity groups. Finally, an ANOVA treatment was conducted to determine significant differencies in ions abondances between groups (1). For each homogenous group, a cultivar was selected to perform Headspace-Solid Phase Microextraction (HS-SPME) followed by Gas Chromatography-Mass Spectrometry (GC-MS) analyzes to connect SIFT-MS data to the composition in volatile compounds (3). Grape varieties were easily distinguishable based only on their SIFT-MS volatilome scan. The technique was able to distinguish high and low aroma compounds producers, and to organise grape varieties by similarity. We proved that SIFT-MS is a really quick and interesting tool with potential application in various fieds of viticulture such as phenotyping of grape varieties based on their volatile composition or studying of the impact of viticultural practices on the grape aroma composition using an easy to implement untargeted approach.

DOI:

Publication date: September 10, 2021

Issue: Macrowine 2021

Type: Article

Authors

Thomas Baerenzung Dit Baron

PPGV, INP-PURPAN, University of Toulouse. ,Alban JACQUES, PPGV, INP-PURPAN, University of Toulouse Olivier GEFFROY, PPGV, INP-PURPAN, University of Toulouse Valérie SIMON, LCA, INP-ENSIACET, University of Toulouse Olivier YOBRÉGAT, IFV Sud-Ouest

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Keywords

sift-ms, grapevine, volatilome, chemometrics, phenotyping

Citation

Climate projections over France wine-growing region and its potential impact on phenology

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Geospatial trends of bioclimatic indexes in the topographically complex region of Barolo DOCG

Barolo DOCG is an economically important wine producing region in Northwest Italy. It is a small region of approximately 70 km2 gross area. The topography is very complex with steep sloped hills ranging in elevation from below 200 m to 550 m. Barolo DOCG wine is made exclusively from the Nebbiolo grape. Bioclimatic indexes are often used in viticulture to gain a better understanding of broader climate trends which can be compared temporally and geographically. These indexes are also used for identifying potential phenological timing, growing region suitability, and potential risks associated with expected climatic changes. Understanding how topography influences bioclimatic indexes can help with understanding of mesoscale climate behaviour leading to improved decision making and risk management strategies. The average monthly maximum and minimum temperatures, the Cool Night Index, the Huglin Index, and the monthly diurnal range (from July to October) were calculated using data from 45 weather stations within a 40 km radius of the Barolo DOCG growing area between the years 1996 and 2019. Linear and multiple regression models were developed using independent variables (elevation, aspect, slope) extracted from a digital elevation model to identify significant relationships. Bioclimatic indexes were then kriged with external drift using independent variables that showed significant relationships with the bioclimatic index using a 100 m resolution grid. The maximum monthly temperatures and the Huglin Index showed consistent significant negative relationships with elevation in all years. The minimum monthly temperatures showed no relationship with elevation but in some months a small but significant relationship was observed with aspect. Due to the lack of a relationship between minimum monthly temperatures and elevation compared to the significant relationship between maximum monthly temperatures and elevation, monthly diurnal range had a negative relationship with elevation.

Local adaptation tools to ensure the viticultural sustainability in a changing climate

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A predictive model of spatial Eca variability in the vineyard to support the monitoring of plant status

Metabolomic discrimination of grapevine water status for Chardonnay and Pinot noir

Water status impact in viticulture has been widely explored, as it strongly affects grapevine physiology and grape chemical composition. It is considered as a key component of vitivinicultural terroir. Most of the studies concerning grapevine water status have focused on either physiological traits, or berry compounds, or traits involved in wine quality. Here, the response of grapevine to water availability during the ripening period is assessed through non-targeted metabolomics analysis of grape berries by ultra-high resolution mass spectrometry. The grapevine water status has been assessed during 2 consecutive years (2019 & 2020), through carbon isotope discrimination on juices from berries collected at maturity (21.5 brix approx.) for 2 Vitis vinifera cv. Pinot noir (PN) and Chardonnay (CH). A total of 220 grape juices were collected from 5 countries worldwide (Italy; Argentina; France; Germany; Portugal). Measured δ13C (‰) varied from -28.73 to -22.6 for PN, and from -28.79 to -21.67 for CH. These results also clearly revealed higher water stress for the 2020 vintage. The same grape juices have been analysed by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS) and Liquid Chromatography coupled to Mass Spectrometry (LC-qTOF-MS), leading to the detection of up to 4500 CHONS containing elemental compositions, and thus likely tens of thousands of individual compounds, which include fatty acids, organic acids, peptides, phenolics, also with high levels of glycosylation. Multivariate statistical analysis revealed that up to 160 elemental compositions, covering the whole range of detected masses (100 –1000 m/z), were significantly correlated to the observed gradients of water status. Examples of chemical markers, which are representative of these complex fingerprints, include various derivatives of the known abscisic acid (ABA), such as phaesic acid or abscisic acid glucose ester, which are significantly correlated with higher water stress, regardless of the variety. Cultivar-specific behaviours could also be identified from these fingerprints. Our results provide an unprecedented representation of the metabolic diversity, which is involved in the water status regulation at the grape level, and which could contribute to a better knowledge of the grapevine mitigation strategy in a climate change context.