Mathematical modeling of fermentation kinetics: a tool to better understand interactions between Torulaspora delbrueckii and Saccharomyces cerevisiae in mixed cultures

As observed in other grape varieties, Red Grenache juice contains low level of volatiles. The main flavor compounds are ” Iock up “as flavorless glycoconjugates which could generate at the wine pH volatile flavorants and constitute the varietal aroma of this cultivar.

The diversity of soil types in the Western Cape of South Africa leads to high levels of within-vineyard variability. Multispectral remote sensing has received a lot of attention recently in the South-African wine industry in an attempt to identify and deal with this variability.

The pinking is a phenomenon that can occur in white wine produced with white grape causing the color change from yellow to red-salmon hue. Even if its appearance is highly variable and dependent to the vintage, the wines from certain grape varieties, such as Sauvignon blanc, Chardonnay, Riesling and Trebbiano di Lugana, have been identified to be more susceptible to the pinking.

Mycobiota encountered from vine to wine is a complex and diversified ecosystem that may impact grape quality at harvest and the sensorial properties of wines, thus leading to off-flavors [1-3]. Among known off-flavors in wine, fresh mushroom aroma (FMA) has been linked to some mold species, naturally pre-sent on grapes, producing specific volatile organic compounds (VOC) [4-5]. The most well-known are 1-octen-3-ol and 1-octen-3-one, although many other VOC are likely involved. To better understand the FMA defect, biotic and abiotic factors impacting growth kinetics and VOC production of selected fungal species in must media and on grapes were studied.

Grape pomace is one of the main by-products generated after pressing in winemaking.Emerging methods, such as ultrasound-assisted extraction with eutectic mixtures, have great potential due to their low toxicity, and high biodegradability. Choline chloride (ChCl) was used as a hydrogen bond acceptor and its corresponding hydrogen bond donor (malic acid, citric acid, and glycerol: urea). Components were heated at 80 °C and stirred until a clear liquid was obtained. Distilled water was added (30 % v/v). A solid-liquid ratio of 1 g pomace per 10 ml of eutectic solvent was used.