Preliminary study of extraction of polysaccharides from pomace by high powered ultrasonic combined with enzymes

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.

Grapevine cultivars are vegetatively propagated to preserve their varietal characteristics. However, spontaneous somatic variations that occur and are maintained during cycles of vegetative growth offer opportunities for the natural improvement of traditional grape cultivars. One advantageous trait for winegrowing is reduced bunch compactness, which decreases the susceptibility to pests and fungal diseases and favor an even berry ripening.

The irrigation water management in the vineyard is a crucial aspect to obtain sustainable quality production over time. Previous studies have set the water requirements to be applied in the vineyard at 30 % of the reference evapotranspiration (ET0), although there are no studies that settle the effects of the frequency of irrigation application on red varieties in Spain. The present study contemplates the application of deficit irrigation (30 % ET0) applying a weekly dose in a single irrigation (T07) or in two irrigation events (T03) per week. The study has been carried out in 2021-2022 with four red varieties in different Spanish wine regions: Garnacha Tinta (Badajoz), Tempranillo (Valladolid), Syrah (Albacete) and Mencía (Lugo). The effects of irrigation frequency on must volatile composition have been evaluated through GC-MS.

Trichoderma is a microorganism present in many agricultural soils and some of its species could be used as natural biological control agents. In this work, the presence of natural populations of Trichoderma was estimated in soil vineyard and its biocontrol capacity against Phaeoacremonium minimum, one of the main agent causals of grapevine trunk diseases instead of using pesticides. Moreover, physicochemical variables in soil such as pH, organic matter and nutrients were evaluated to determine a possible correlation to natural populations of Trichoderma.

Wine acidity is a parameter of great importance that influences different quality factors of the product such as biological stability or organoleptic characteristics. In the current context of climate change, which gives rise to wines with higher levels of ethanol and lower acidity, the biological acidification with yeast species such as Lachancea thermotolerans could be a solution.
In this work, the effect of the inoculation of different L. thermotolerans on the acidity of wine was studied.