IVAS Session 2 – Keynote and full talk

Climate change has become a major challenge for grape and wine production around the world

An organoleptic defect, called fresh mushrooms off-flavor (FMOff), appeared in wines and spirits since the 2000’s. Numerous researches demonstrated that octen-3-one, 3-octanol and octen-3-ol (C8 compounds) were involved in the mushroom off-flavor in wines

The Maillard reaction (MR) is a non-enzymatic reaction between reducing sugars and amino acids, resulting in the production of volatile and flavour-active compounds.

Anthocyanins are the main pigments present in young red wines, being responsible for their intense red color. These pigment in aqueous solutions occur in different forms in equilibrium that are dependent on the pH

Sulfur dioxide is widely used during winemaking as an antioxidant and antimicrobial agent. Bisulfite (HSO3−), the predominant form of SO2 at wine pH, reacts with several wine components forming sulfonated adducts.

Volatile sulfur compounds (VSCs), mainly hydrogen sulfide and methanethiol (H2S and MeSH), are the responsible for reductive off-odor in wine.

Dimethyl sulfide (DMS) is a compound that accumulate in wine for the early years of ageing 1. During this stage, which is often carried out in the bottle, the environmental conditions are conducive to the release of DMS from its precursors, already present in grapes2

Light-induced reactions can be responsible for detrimental changes of white and rosé wines. This is associated to the photo-degradation of riboflavin (RF) and of methionine (Met) causing the appearance of light-struck taste (LST).

Oxygen plays a key role in the evolution of wine chemistry, within the non-volatile matrix. Polyphenol composition and structure, as well as the process of tannin polymerisation are directly impacted by oxidation, and this can occur during both fermentation and ageing.

(+)-Catechin—laccase oxidation dimeric standards were hemi-synthesized using laccase from Trametes versicolor in a water-ethanol solution at pH 3.6.

Acidity is often touted as a predictor of wine ageability, though surprisingly few studies have systematically investigated the chemical basis for this claim.