Comparative proteomic analysis of wines made from Botrytis cinerea infected and healthy grapes reveal interesting parallels to the gushing phenomenon in sparkling wine

Botrytis cinerea is a fungus that causes common infection in grapes and other fruits. In winemaking, its presence can be both considered desirable in the case of noble rot infection or undesirable when grey rot is developed. This fungus produces an extracellular enzyme known as laccase which is able to cause oxidation of phenolic compounds present in must and wine, causing most of the times a decrease in its quality and problems during the winemaking process [1]. Material and methods: Three B. cinerea strains (B0510, VA612 and RM344) were selected and grown in a liquid medium adapted from one previously described [2]. The enzyme was isolated by tangential ultrafiltration of the culture medium using a QuixStand system equipped with a 30 KDa filtration membrane.

Among red wines ethyl esters, those from short hydroxylated and branched-chain aliphatic acids constitute a family with a particular behavior and sensory importance. They have been previously discussed in the literature [1] and recent studies have established that some of them were strongly involved in of red wines’ fruity aroma [2]. As some among them have an asymmetrical carbon atom, it seemed important to separate their different enantiomers to obtain an accurate assessment of their organoleptic impact. Three chiral esters have been identified, presenting alkyl and/or hydroxyle substituants: ethyl 2-hydroxy-4-methylpentanoate, ethyl 2-methylbutanoate, and ethyl 3-hydroxybutanoate.

Chemical and sensory changes occurring in red wine during ageing in oak barrique are due to the slow and gradual entrance of oxygen along with a release of ellagic tannin from the wood. Though oxygen can enter the cask through the bunghole, it is not clear the role of permeation through the wood staves as well as the amount of oxygen entering by permeation. The distribution of the released ellagic tannins in the wine ageing is also unknown. The oxygen passing through the bunghole may have a different wine ageing effect compared to the oxygen permeating through the wooden staves owing to the uneven ellagic tannin concentration throughout the wine.

One of the major determinants of wine quality is the aroma. Wine aroma is the human perception of the matrix of grape and yeast derived volatiles and their interaction that contribute to flavour wine. Most common are higher alcohols, ester and aldehydes. In previous studies the formation of characteristic volatile compounds have been linked to the metabolism of branched-chain and aromatic amino acids
(BCAAs) in synthetic grape must. Here we report on an investigation to assess the impact of the initial amino acid concentration on the production of aroma compounds by the industrial yeast VIN13 grown in both synthetic and real grape musts.

Vitis vinifera is one of the most diffused grapevines over the word and it is the raw material for high quality wines production. The availability of more resistant interspecific hybrid vine varieties, developed from crosses between Vitis vinifera and other Vitis species, has generating much interest, also due to the low environmental effect of production. However, hybrid grape wine composition and varietal differences between interspecific hybrids are not well defined. Different studies revealed that wine consumption has health effects due to its high content of antioxidants, as phenolic compounds. In particular, simple phenols are appreciated not only for their physiological health benefits, including antioxidant, anti-inflammatory and cardioprotective effects, but also because they affect wines organoleptic profile and have a significant role in defining their nutritional characteristics.