Antimicrobial activity of oenological polyphenols against Gram positive and Gram negative intestinal multidrug-resistant bacteria

Vine cane extracts are a valuable byproduct due to their rich content of polyphenols, vitamins, and other beneficial compounds, which can affect and benefit the vine and the grapes. This study aims to evaluate the response of grapevine plants to irrigation with water supplemented with a vine cane extract, both at physiology response and phenolic composition in different parts of the plant (root, trunk, shoot, leaf, and berry).
Cane extract was obtained by macerating crushed pruning residues with warm water (5:1) and pectolytic enzymes. Two-year-old potted plants were irrigated with water (Control) while others were irrigated with cane extracts, either at 1:4 (w/v, cane extract/water; T 1:4) or at 1:8 (w/v, cane extract/water; T 1:8).

Improving our knowledge on biotic and abiotic factors that influence the composition of the grapevine mycobiome is of great agricultural significance, due to potential effects on plant health, productivity, and wine characteristics. Among the various environmental factors affecting the morphological, physiological, biochemical and molecular attributes of grapevine, drought stress is one of the most severe, becoming increasingly an issue worldwide.

Proanthocyanidins are important phenolic fraction for wine quality, contributing to astringency, bitterness and color. Their metabolism begins in the mouth and continues throughout the gastrointestinal tract; however, most of them are accumulated in the colon where are metabolized by the intestinal microbiota, giving rise to a whole series of phenolic acids that may have greater activity at physiological level than the precursors[1]. This study aimed to evaluate in vitro the bioaccessibility of proanthocyanidins in a red wine developed by Bodegas Pradorey, as well as to evaluate the potential effect of intestinal microbiota on polyphenols metabolism identifying and quantifying secondary metabolites.

Based on historical vine cultivation, the recent development of wine production in Drama wine region (Greece) has led to vine cultivation expansion of white and red varieties. The current cultivation of 500 ha of vineyards is expected to increase in the coming years. Natural terroir units (NTU) have been designed recently to support the production of high quality wines in the region [1]. The aim of this work is to evaluate the relevancy of the proposed NTUs regarding their suitability to produce wines of specific sensorial identity, and to provide guidelines for correct site selection for the expanding wine industry of the region.

The increasingly frequent heat waves during grape ripening pose challenges for premium wine grape production. This makes the development of irrigation and canopy management techniques of great importance to maximize yield and grape quality. A field experiment was carried out during 2021 and 2022 using Manto negro wine grapes to study the effect of two irrigation strategies and different light exposure levels on grape quality.