Withering of the ‘Moscato giallo’ grapes under covered space

Brettanomyces/Dekkera yeasts in wine are able to produce various spoilage compounds that are, at high concentration, detrimental to wine quality. The principal spoiler compounds associated with Brettanomyces spp. are vinyl and ethyl-phenols that are responsible for off- odours described as “animal”, “medicinal”, “sweaty leather”, “barnyard”, “spicy” and “clove-like”.

The recent expansion of arid areas due to climate change is putting grapevine and the other traditional productions at risk in all Mediterranean countries with a limited availability of fundamental resources such as water. It is possible to improve the resilience of vineyards by developing sustainable agricultural practices based on biological and natural resources such as endophytic microorganisms that colonize inner plant tissues, and which can potentially increase the tolerance to abiotic stresses. A selection of grapevine endophytes was conducted from 2021 to 2023 as part of the PRIMA project PROSIT.

Mannoproteins (MPs) are released from the yeast cell wall during alcoholic fermentation and aging on the lees, and influence aspects of wine quality such as haze formation and colour stability. Yet, as this is a slow process with microbiological and sensory risks, the exogenous addition of extracted MPs poses an efficient alternative. While Saccharomyces cerevisiae has long been studied as a prominent source for MPs extraction, their structure and composition greatly differ between yeast species. This may influence their behaviour in the wine matrix and subsequent impact on wine properties. However, although wine yeast species other than S. cerevisiae possibly present an untapped source of MPs, they are still ill-characterised in terms of chemical composition and influence on wine.

Wine quality is defined by sensory and physico-chemical characteristics. In particular, sensory features are very important since they strongly condition wine acceptability by consumers. However, the evaluation of sensory quality can be subjective, unless performed by a tasting panel of experienced tasters. Therefore, it is of great relevance to establish relationships between objective chemical parameters and sensory perceptions, even though the complexity of wine composition makes it difficult. In this sense, more reliable relationships can be found for a particular wine typology or variety. The present study aimed to predict the perceived sensory quality from the physico-chemical parameters of ‘Barbera d’Asti’ DOCG red wines (Italy).

Powdery mildew, caused by Erysiphe necator, is a widespread disease that causes high economical losses in viticulture. The main strategy to control the disease is the recurrent application of sulphur based phytochemical compounds. However, in order to reduce their accumulation in the environment and promote the sustainability of the sector, the European Commission has applied restrictions to the number of pesticide treatments and the maximum quantity of fungicides to be applied in viticulture. Seaweeds, in particular macroalgae, are marine resources rich in sulphated polysaccharides with bio-protective potential for the plant, representing an environmentally-friendly alternative approach for sustainable wine production.