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…

Underpinning terroir with data: rethinking the zoning paradigm

Agriculture, natural resource management and the production and sale of products such as wine are increasingly data-driven activities. Thus, the use of remote and proximal crop and soil sensors to aid management decisions is becoming commonplace and ‘Agtech’ is proliferating commercially; mapping, underpinned by geographical information systems and complex methods of spatial analysis, is widely used. Likewise, the chemical and sensory analysis of wines draws on multivariate statistics; the efficient winery intake of grapes, subsequent production of wines and their delivery to markets relies on logistics; whilst the sales and marketing of wines is increasingly driven by artificial intelligence linked to the recorded purchasing behaviour of consumers. In brief, there is data everywhere!

Opinions will vary on whether these developments are a good thing. Those concerned with the ‘mystique’ of wine, or the historical aspects of terroir and its preservation, may find them confronting. In contrast, they offer an opportunity to those interested in the biophysical elements of terroir, and efforts aimed at better understanding how these impact on vineyard performance and the sensory attributes of resultant wines. At the previous Terroir Congress, we demonstrated the potential of analytical methods used at the within-vineyard scale in the development of Precision Viticulture, in contributing to a quantitative understanding of regional terroir. For this conference, we take this approach forward with examples from contrasting locations in both the northern and southern hemispheres. We show how, by focussing on the vineyards within winegrowing regions, as opposed to all of the land within those regions, we might move towards a more robust terroir zoning than one derived from a mixture of history, thematic mapping, heuristics and the whims of marketers. Aside from providing improved understanding by underpinning terroir with data, such methods should also promote improved management of the entire wine value chain.

Diagnosis of soil quality and evaluation of the impact of viticultural practices on soil biodiversity in a vineyard in southwestern France

Viticulture is facing two major changes – climate change and agroecological transition. In both cases, soil quality is seen as a lever to move towards a more sustainable viticulture. However, soil biological quality is little considered in the implementation of viticultural practices. Gascogn’Innov (2017-2022) is an Operational Group funded by the European Innovation Partnership for Agriculture. As such, it brings together winegrowers from the south-west of France, scientists, advisors and technicians, around a project focused on viticultural soil biological functioning and the design of technical routes more respectful toward soil heritage. To achieve this, the project aims to acquire references on the impact of viticultural practices on soil biology from a dynamic way, and to test a methodology to integrate information provided by the soil bioindicators to manage farming systems. A set of indicators of soil biological quality are evaluated in the project: microorganisms (bacteria and fungi abundance and diversity), fauna (abundance and diversity of nematodes and earthworms), physico-chemical characteristics, soil structure assessment and degradation rate of organic matter. Based on a network of 13 plots that have been subject to an initial diagnosis in 2017, several agronomical practices to restore soil fertility are experimented to redesign the cropping system (for instance plant cover, organic matter inputs, reduction of herbicides, mineral fertilizers). System redesign was made in collaboration by winegrowers and an interdisciplinary group of experts (agronomists, biologists). Several indicators are measured on vine and soil at each vintage to assess vine health and productivity. At the end of the project (2021), a final diagnosis was carried out. Gascogn’Innov allowed to create a regional database on the quality of wine-growing soils, which permitted to evaluate the effect of practices according to soil types. Especially, decreasing the intensity of tillage and increasing the duration and diversity of grass coverage tends to increase the abundance of all the organisms studied. This project confirmed the value of soil biological quality indicators to drive the sustainability of practices, but also highlighted the key-role of expertise, in both agronomy and soil biology, to help winegrowers understand and appropriate their soil quality diagnoses.

Assessing the climate change vulnerability of European winegrowing regions by combining exposure, sensitivity and adaptive capacity indicators

Winegrowing regions recognized as protected designations of origin (PDOs) are closely tied to well defined geographic locations with a specific set of pedoclimatic attributes and strictly regulated by legal specifications. However, climate change is increasingly threatening these regions by changing local conditions and altering winegrowing processes. The vulnerability to these changes is largely heterogenous across different winegrowing regions because it is determined by individual characteristics of each region, including the capacity to adapt to new climatic conditions and the sensitivity to climate change, which depend not only on natural, but also socioeconomic and legal factors. Accurate vulnerability assessments therefore need to combine information about adaptive capacity and climate change sensitivity with projected exposure to new climatic conditions. However, most existing studies focus on specific impacts neglecting important interactions between the different factors that determine climate change vulnerability. Here, we present the first comprehensive vulnerability assessment of European wine PDOs that spatially combines multiple indicators of adaptive capacity and climate change sensitivity with high-resolution climate projections. We found that the climate change vulnerability of PDO areas largely depends on the complex interactions between physical and socioeconomic factors. Homogenous topographic conditions and a narrow varietal spectrum increase climate change vulnerability, while the skills and education of farmers, together with a good economic situation, decrease their vulnerability. Assessments of climate change consequences therefore need to consider multiple variables as well as their interrelations to provide a comprehensive understanding of the expected impacts of climate change on European PDOs. Our results provide the first vulnerability assessment for European winegrowing regions at high spatiotemporal resolution that includes multiple factors related to climate exposure, sensitivity, and adaptive capacity on the level of single winegrowing regions. They will therefore help to identify hot spots of climate change vulnerability among European PDOs and efficiently direct adaptation strategies.

Long-term drought resilience of traditional red grapevine varieties from a semi-arid region

In recent decades, the scarcity of water resources in agriculture in certain areas has been aggravated by climate change, which has caused an increase in temperatures, changes in rainfall patterns, as well as an increase in the frequency of extreme phenomena such as droughts and heat waves. Although the vine is considered a drought-tolerant specie, it has to satisfy important water requirements to complete its cycle, which coincides with the hottest and driest months. Achieving sustainable viticulture in this scenario requires high levels of efficiency in the use of water, a scarce resource whose use is expected to be severely restricted in the near future. In this regard, the use of drought-tolerant varieties that are able to maintain grape yield and quality could be an effective strategy to face this change. During three consecutive seasons (2018-2020) the behavior in rainfed regime of 13 traditional red grapevine varieties of the Spain central region was studied. These varieties were cultivated in a collection at Centro de Investigación de la Vid y el Vino de Castilla-La Mancha (IVICAM-IRIAF) located in Tomelloso (Castilla-La Mancha, Spain). Yield components (yield, mean bunch and berry weight, pruning weight), physicochemical parameters of the musts (brix degree, total acidity, pH) and some physiological parameters related with water stress during ripening period (δ13C, δ18O) were analysed. The application of different statistical techniques to the results showed the existence of significant differences between varieties in their response to stressful conditions. A few varieties highlighted for their high ability to adapt to drought, being able to maintain high yields due to their efficiency in the use of water. In addition, it was possible quantify to what extent climate can be a determinant in the δ18O of musts under severe water stress conditions.

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.