Publications by authors named "J Valls-Fonayet"

A varietal origin of eugenol was previously demonstrated in Baco blanc, a major grapevine variety used to produce Armagnac wine spirits. Eugenol was found in high amount, both as the free and as unidentified glycosylated forms. To reveal their identity, a specific method was developed and applied to berry skin extracts.

View Article and Find Full Text PDF

Resveratrol and its glucoside, piceid, are the primary stilbenes present in wine. These compounds are well known for their pharmaceutical properties. However, these compounds can undergo chemical transformations in wines, such as polymerization in the presence of metallic reagents.

View Article and Find Full Text PDF

Background: Priming plants with natural products is extensively studied in the agricultural field to reduce the use of synthetic and copper-based pesticides. Previous studies have shown that Oregano essential oil vapour (OEOV) is an effective priming agent against downy mildew (DM) in grapevine (Vitis vinifera L. cv.

View Article and Find Full Text PDF
Article Synopsis
  • The study explored the effectiveness of five different HILIC stationary phases for retaining various polyphenols, discovering that silica-based supports generally did not perform well except for anthocyanins.
  • Retention of phenolics was most effective with zwitterionic, amide, and amino stationary phases, and the choice of mobile phase, particularly using formic acid instead of TFA, significantly influenced retention results.
  • The research highlighted the advantages of using mass spectrometry as a detector for quantifying polyphenols in complex natural extracts, particularly under conditions where resolution between compounds was difficult.
View Article and Find Full Text PDF

Background: Stilbenoid extracts, such as those originating from grapevine by-products (e.g. canes), are of interest for use as biopesticides in vineyard owing to their antimicrobial activities.

View Article and Find Full Text PDF