IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 LC-HRMS data analysis of natural polymer homologue series Application on wine neutral oligosaccharides

LC-HRMS data analysis of natural polymer homologue series Application on wine neutral oligosaccharides

Abstract

Although oligosaccharides have much impact both on health (prevention of diabetes, cardiovascular disease), and on the perception of wine (sweetness, astringency, acidity or bitterness), information on their composition in wine is still limited. In a previous work, neutral oligosaccharide fractions isolated from wine were analyzed. The results present a composition of different monosaccharide units (hexose, pentose, uronic acid and deoxyhexose) and show the presence of several structures of oligo-rhamnogalacturonan type I substituted through the rhamnose moieties by arabinan and/or galactan chains.
The aim of this work is to explore new approaches for processing LC-HRMS data to identify these compounds containing repeating units (homologous series) such as arabinans or galactans.  The presented approach allows visualization of these series in the form of a Kendrick mass defect (KMD) plot to facilitate their characterization.
The chromatographic profiles obtained by LC-HRMS analysis of these fractions showed a poorly resolved bump, and the mass spectra were very complex consisting of mono, di, and tricharged ions peaks over a mass range between 500 and 2500. They allowed however to visualize numerous series formed by separated monocharged peaks of 132 m/z, or dicharged peaks of 66 m/z, i.e. a pentose unit.
The construction of the KMD plot is done with a change of scale for which the mass taken into account of (C5H8O4) is 132.0000 (nominal mass) instead of 132.0423 Da (exact mass). All masses of the spectrum are thus recalculated and called Kendrick masses (KM). The mass defect (KMD) for each peak of the spectrum is the difference between its Kendrick mass and its nominal mass. All compounds of the form R-(C5H8O4)n, R being a common radical, will have the same mass defect. The graphical representation, thus makes it possible to visualize the set of compounds that differ only by their number of pentose units on the same line.
In our case, the accuracy of the measurement at masses above m/z 1000 does not allow this calculation. This limitation was resolved by processing the data with the Compound DiscovererTM software (ThermoScientific) to obtain a list of monocharged masses, for which several crude formulas were proposed. A sorting of these crude formulas was carried out considering the possible ratios between number of carbons, oxygens and hydrogens. The exact masses of the 2045 remaining formulas were then calculated and allowed to draw the Kendrick mass defect plot.
Finally, the Kendrick diagram approach allows visualization of the homologous series of arabinoses. Identification hypotheses were proposed for 555 compounds attributed to oligo-rhamnogalacturonan type I, and its arabinans/galactans side chains degradation products. This study demonstrated the relevance of this analytical approach for the determination of the structure of wine oligosaccharides.

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Poster

Authors

Meudec Emmanuelle1, Vallverdu-Queralt Anna2,3, Sommerer Nicolas1, Cheynier Véronique1, Williams Pascale1 and Doco Thierry1

1SPO, INRAE, Univ Montpellier, Institut Agro, Montpellier, France
INRAE, PROBE research infrastructure, PFP Polyphenol Analytical Facility, Montpellier, France <<

2Department of Nutrition, Food Science and Gastronomy, XIA, Faculty of Pharmacy and Food Sciences, Institute of Nutrition and Food Safety (INSA-UB), University of Barcelona, Barcelona, Spain
3CIBER Physiopathology of Obesity and Nutrition (CIBEROBN), Institute of Health Carlos III, Madrid, Spain 

Contact the author

Keywords

HRMS, oligosaccharides, homologue series, Kendrick mass defect plot, KMD

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Towards a regional mapping of vine water status based on crowdsourcing observations

Monitoring vine water status is a major challenge for vineyard management because it influences both yield and harvest quality. It is also a challenge at the territorial scale for identifying periods of high water restriction or zones regularly impacted by water stress. This information is of major importance for defining collective strategies, anticipating harvest logistic or applying for irrigation authorisation. At this spatial scale, existing tools and methods for monitoring vine water status are few and often require strong assumptions (e.g. water balance model). This paper proposes to consider a collaborative collection of observations by winegrowers and wine industry stakeholders (crowdsourcing) as an interesting alternative. Indeed, it allows the collection of a large number of field observations while pooling the collection effort. However, the feasibility of such a project and its interest in monitoring vine water status at regional scale has never been tested.

The objective of this article is to explore the possibility of making a regional map of vine water status based on crowdsourcing observations. It is based on the study of the free mobile application ApeX-Vigne, which allows the collection of observations about vine shoot growth. This information is easy to collect and can be considered, under certain conditions, as a proxy for vine water status. This article presents the first results obtained from the nearly 18,000 observations collected by winegrowers and wine industry stakeholders during 2019, 2020 and 2021 seasons. It presents the vine shoot growth maps obtained at regional scale and their evolution over the three vintages studied. It also proposes an analysis of the factors that favoured the number of observations collected and those that favoured their quality. These results open up new perspectives for monitoring vine water status at a regional scale but above they provide references for other crowdsourcing projects in viticulture.

A multidisciplinary approach to evaluate the effects of the training system on the performance of “Aglianico del Vulture” vineyards

Vineyards are complex agro-ecosystems with high spatial and temporal variability. An efficient training system may counteract the adverse effects of this variability. Moreover, considering the climate change issues, choosing an efficient training system that enhances water use and protects the vines from radiative thermal stress has become a priority for the farmers. A multidisciplinary approach that assesses the soil-crop-yield-wine relationships of vineyards in a distributed and holistic way could bring added knowledge on the behavior of the different training systems. This ongoing research aimed to implement a multidisciplinary approach to study the behavior of “Aglianico del Vulture” grapevines trained with two different systems: a spurred cordon (SC) and an “Alberello in parete” (AL), grown in a high-quality wine production area of Basilicata region (Italy). The approach merged several methods and scales of soil, ecophysiology, must/wine quality, and spectral data collection to assess the influence of the training system. Homogeneous zones (HZs) in both training systems were defined through a procedure based on geomorphological classification, unmanned aerial vehicles (UAV) images analysis, and a traditional soil survey supported by geophysical scanning. During the 2021 season, TDR probes monitored soil water content, while grapevine health status was assessed using eco-physiological measurements (LWP, chlorophyll content, PSII photosynthetic efficiency, LAI, and point-based field spectroscopy). These grapevine in-vivo measurements validated the spectral vegetation indexes (NDVI, RENDVI, CVI, and TVI) derived from the UAV multispectral imagery, which monitored the grapevine status in a distributed and non-invasive way. Grape yield, quality of berries, must and wine were measured to assess the effects of the training systems. The first experimental year results showed the variability of the vineyards and revealed relationships among soil parameters, crop characteristics, and vegetation indices of the SC and AL training systems. This multidisciplinary study could bring new insights into the vineyard training system’s effects on grape yield and wine quality.

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.

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)