Valorization of grapevine leaves: screening of polyphenol composition in 50 cultivars
Grapevine leaves are known to contain different polyphenols such as flavonols, catechins and stilbenes, which are known to act as main contributors for plant defense against pathogens (1). While the composition for some major cultivars has been studied, there is lack of systematic comparison about the content of these compounds in the wide ecodiversity of Vitis vinifera cv. Recent advances in Mass Spectrometry-based Metabolomics allow a wider and more sensitive description of these polyphenols, as instance of those present in leaves (2). Such information could help to better explain leaf traits regarding the development of the leaf or to the plant tolerance to a pathogen. Moreover, these compounds offer appealing applications for human health due to their antioxidant activities. Grapevine leaves being a disposable byproduct in viticulture, their potential valorization as a source of polyphenols is a topic of interest.
Our objective was to compare the diversity of grapevine leaves composition by screening qualitatively and quantitatively the polyphenol content in leaves of 50 cultivars grown in the same field of an experimental collection at Bordeaux INRAe. Fresh leaves were collected at the same period in summer, freeze-dried, ground to a fine powder and polyphenols were extracted twice with combination of organic solvents (100% and 70% methanol). A targeted HPLC-MS/MS approach was used for the quantification with available standards of 60 different polyphenols.
The results showed high variability in polyphenols content. Nevertheless, caftaric acid and quercetin 3-glucuronide were the major compounds detected in all leaves. Flavanols, and more particularly the ratio catechin/epicatechin, could be explored as markers to determine leaf cultivar, ranging from 0.5 to 42. Stilbenes were minor compounds in all leaves, found mainly in the forms of trans- and cis-piceid. Minor presence of resveratrol and its oligomers was assessed by HPLC-HRMS/MS.
Acknowledgements: The authors wish to thank the UE Viticole and Louis Bordenave for management of the experimental vineyard and the support of Bordeaux Metabolome
(1) Lemaitre-Guillier et al (2021) VOCs Are Relevant Biomarkers of Elicitor-Induced Defences in Grapevine. https://doi.org/10.3390/molecules26144258
(2) Goufo et al (2020). A Reference List of Phenolic Compounds (Including Stilbenes) in Grapevine (Vitis vinifera L.) Roots, Woods, Canes, Stems, and Leaves. doi: 10.3390/antiox9050398
Issue: ICGWS 2023
1Enology, Univ. Bordeaux, Bordeaux Sciences Agro, INRAE, ISVV, 33140 Villenave d’Ornon, France
2Instituto de Ciencias de la Vid y el Vino, 26007 Logroño (La Rioja) ESPAÑA
3EGFV, Univ. Bordeaux, Bordeaux Sciences Agro, INRAE, ISVV, 33140 Villenave d’Ornon, France