Impact of cover crop in vineyard on the musts volatile profile of Vitis vinifera L. Cv Syrah

Abstract

Grape aromatic characteristics are very important for the production of quality wines. The concentrations of volatile compounds in grape berries from vines with cover crops have been scarcely studied. For this reason, the aim of this work was to evaluate the influence of “Zulla” cover crop on the volatile profiles of organically grown Shyraz variety grapes. For this purpose, volatile profiles of grapes obtained from vines with three different amount of cover crop (one line, two lines and four lines) and without cover crop, over two harvests (2019 and 2020) were determined. The grape samples came from Jerez a warm climate zone. Must volatile compounds were determined by sequential sorptive extraction with Twisters by immersion (SBSE) and headspace (HSSE), followed by GC-MS analysis [1]. A total of 159 compounds were determined and, most of them were influenced by the presence of cover crop. The amount of methyl ester was directly correlated with the amount of “Zulla” cover crop. The results of principal component analysis (PCA) showed that PC1 grouped the samples according harvest and PC2 according to amount of cover crop, separating clearly the samples obtained without cover crop, in both harvests. It was observed a reduction of free volatile compounds when the amount of cover crop applied increased, in both harvests. Then, cover crop had an effect over volatile profile of Shyraz grapes.