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Abstract Background The new trend demanding for “natural” agri-food products has encouraged the application of more sustainable and eco-friendly farming methods, which limit or avoid the use of synthetic chemicals. This approach is increasing in viticulture, one of the sectors with the highest commercial value since grapes and derived products are largely consumed foodstuffs, with appreciated nutritional and sensory features. In this work, 1H Nuclear Magnetic Resonance spectroscopy (1H NMR) was applied for the metabolic profiling of cv. Italia table grapes samples, from the same origin area, cultivated with different treatments (biodynamic, organic and integrated) and collected in three subsequent vintages. Multivariate statistical analysis was performed on NMR-data with the aim of comprehensively researching the possible influences on metabolites due to the use of diverse agricultural practices. Results Both inter-annual variability (2020, 2021 and 2022 vintages) and different vineyard treatments (biodynamic, organic and integrated) resulted as significant drivers for samples differentiation in the preliminary unsupervised analysis of the (1H NMR spectra derived) metabolic profile data. Nevertheless, supervised data analyses showed that inter-vineyards variability, due to application of diverse farming methods, had a comparable discriminating effect with respect to harvesting years. Ethanol, sugars (as α-/β-glucose), organic acids (as malate) and amino acids (as arginine, leucine, glutamine) resulted the most viticultural practices-dependent metabolites. Interestingly, results from pairwise comparisons between treatments indicated the biodynamic samples with respect to the organic ones as the best-observed differentiation. This was followed by the biodynamic vs integrated and organic vs integrated samples comparisons, in decreasing discrimination order, as confirmed by the descriptiveness and predictive ability parameters of the corresponding pairwise OPLS-DA models. Conclusions Results highlighted that metabolites’ composition in cv. Italia table grapes juice is significantly affected by the use of different kinds of vineyard managements (biodynamic, organic and integrated, here investigated). Metabolomics study, here employing 1H NMR spectroscopy combined with multivariate statistical analysis, offers powerful tools to elucidate the metabolic differences among classes of samples. Graphical Abstract

Abstract Background Xylella fastidiosa is a Gram-negative bacterium which lives in the xylem of plants, causing its occlusion and other alterations inducing eventually the death of the infected plants. In Salento, the sub-peninsula in the south-eastern of Apulia Region (southern Italy), the infection of X. fastidiosa has been associated with the widespread presence of CoDiRO (complex of parasitic agents that constitute the so-called “olive quick decline syndrome”) and currently represents a serious local emergence. The need to adopt specific agronomic measures to contrast the further disease spread has been recently raised. The extensive NMR-based metabolomic approach to study the metabolic effects of CoDiRO on local olive cultivars such as Ogliarola salentina and Cellina di Nardò was used. Results In this study, the effects of a CE approved fertilizer containing zinc, copper, and citric acid, known as DENTAMET®, on CoDiRO-exhibiting olive trees infected by X. fastidiosa were studied by 1H NMR spectroscopy. The changes in the metabolomic profiles of aqueous extracts obtained from leaves of the two olive cultivars are reported. Upon the DENTAMET® treatments, different and opposite polyphenolic and sugars patterns in the two cultivars, which showed a different incidence and severity of disease before the treatments, were detected. Conclusions Differences in the sugars and polyphenols content of treated versus untreated trees could potentially contribute to the syndrome monitoring and might be related to the X. fastidiosa presence. Graphical abstract Apulian (Salento) CoDiRO-exhibiting olive trees infected by X. fastidiosa have been studied by 1H NMR spectroscopy. Changes in the metabolomic profiles are reflected in different sugars and polyphenols content after DENTAMET®-treatment