Taking advantages of innovative chemometric tools to unveil vineyard ecosystem dynamics: look across volatile secondary metabolites

Abstract

Sustainable viticulture and winemaking continue to represent huge challenges, where a better knowledge about the functional role of biodiversity in the vineyard ecosystems is required. Particular attention should be devoted to the spatial and temporal interactions between varieties for a specific demarcated region and clime and vineyard conditions. Taking advantages of chemometric tools, this talk aims to provide advances to examine interactions between climatic conditions, vineyard ecosystem and physicochemical data, namely data from parameters related with grape technological maturity state and secondary volatile metabolites, associated to grapes aroma potential. High volume of information from high throughput technologies, namely from comprehensive two-dimensional gas chromatography (GC×GC-TOFMS) used for volatile fraction characterization, were selected. All the data are intrinsically correlated and generally produced by another multivariate set of factors or continuous variables, collected in what is defined as the design matrix. Such design factors usually involve the presence of a treatment, but other sources of biological or technical variability in the data are often measured as well. The ASCA framework, based on ANOVA and PCA, leads to promising results [1]. Also, Common components and specific weights analysis, has been reported as a chemometric method for dealing with complexity of food products [2]. Thus, on this talk it will be discussed the applicability of several chemometric tools, particular focus will be done on innovative approaches that combine data sets with fixed and random effects. As case study, it was selected a set of varieties cultivated in Bairrada Appellation (Portugal), collected across five consecutive years. Combination of linear mixed models with Principal Component Analysis (LiMM-PCA) was applied to analyse the impact of three factors, harvest, grape variety and vineyard on a set of several physical-chemical parameters. LiMM-PCA allowed to analyse dataset with underlying design, which included both fixed (harvest and cultivar) and random (vineyard) factors. The vineyards selected for sampling were considered representative of the Appellation. Thus, considering the vineyard as a random factor permitted to draw conclusions about the Appellation under study as a whole. In addition, the approach used enabled the ranking of variables importance and the assessment of the adaptability of each variety, providing a high-value tool for supporting vineyard and wine production management, amid current climate challenges.

Acknowledgments

This work was supported by National Funds by FCT, through the Associate Laboratories LAQV-REQUIMTE (UIDB/50006/2020 and UIDP/50006/2020) and CESAM (UIDP/50017/2020; UIDB/50017/2020; LA/P/0094/2020), and under the scope of the Strategic Project to Support the Wine Industry in the Central Region (CENTRO-04-3928-FEDER-000001).

References

[1] Martin, M., Govaerts, B., (2020). J. Chemometrics, e3232, 1-10.

[2] Mazerolles, G., Hanafi, M., Dufour, E., Bertrand, D., Qannari, E.M. (2006). Chemom. Intell. Lab. Syst. 81, 41 – 49.