Determination of secondary metabolites as quality and typicalness tracers in autochthonous vitis vinifera grapes and wines from Ischia isle

In the context of climate change and the need to reduce inputs, optimising photosynthesis and grapevine performance requires a better understanding of the interactions between water status, nitrogen availability, and source-sink relationships.

Context and purpose. Climate change and the demand for reducing inputs, including chemical compounds, present significant challenges for perennial fruit crops like grapes and apples.

Despite its relevance for wine quality and stability, red wine colloids have not still been
sufficiently investigated, an occurrence due to the lack of suitable analytical techniques to study them as they are present in wine.

Phenolic compounds are among the most important quality factors of wines. They contribute to the organoleptic characteristics of wine such as colour, astringency, and bitterness. Although tannins found in wine can come from microbial and oak sources, the main sources of polyphenols are skin and seed from grapes. Yet, the link between grape seed phenolic content and wine composition, or even the link between seed maturity stage and wine composition are poorly studied. This work describes and explains the seed tannins kinetics release in wine, but also the impact of seed maturity stage on seed tannins extractability.

Vineyards from mild temperature, high humidity locations receive often treatments with fungicides to prevent damages produced by fungi responsible for mildium, oidium and botrytis infections. In addition, insecticides are also applied to vineyards to fight again pests, which affect directly, or indirectly (as vectors of different diseases), their productivity. A fraction of the above compounds reaches the soil of vineyards, either during application, or when released from the canopy of vines due to rain-wash-off. Thereafter, depending on soil conditions (pH, organic matter) and environmental variables (regimen of rain, slope of vineyards), they might persist in this compartment, be degraded and/or transferred to water masses, modifying the biodiversity of soils and/or affecting the quality of water reservoirs.