Impact of environmental conditions in vscs production during wine fermentation by Saccharomyces cerevisiae

As environmental issues come more to the fore, vineyards residues are being looked at as solutions rather than problems. Aiming to develop a sustainable methodology for musts acidity correction in the process of winemaking, much needed in warm regions, the present study was performed according to Circular Economy values.

Las tendencias actuales del mercado apuntan hacia el consumo de vinos con menor contenido en alcohol, y, por otra parte, de vinos con características especiales y diferenciadoras, siendo los vinos con indicación geográfica o denominación de origen los más demandados.

The use of pesticides for vine growing is responsible for generating an important volume of wastewater. In 2009, 13 processes were authorized for wastewater treatment but they are expensive and the toxicological impact of the secondary metabolites that are formed is not clearly established. Recently photodecomposition processes have been studied and proved an effectiveness to degrade pesticides and to modify their structures (Maheswari et al., 2010, Lassale et al., 2014). In this field, Pulsed Light (PL) seems to be an interesting and efficient process (Baranda et al., 2017). Therefore, the aim of this work was to investigate the PL technology as a new process for the degradation of pesticides.

Tangible variation of sensory characteristics is often perceived in wine aged in similar barrels. This variation is mostly explained by differences in the wood chemical composition, and in the production of the barrels. Despite these facts, the literature concerning barrel-to-barrel variation and its effect on wine sensory and chemical characteristics is very scarce [1]. In this study, the barrel-to-barrel variation in barrel-aged wines was examined in respect of the most important phenolic compounds of oenological interest and chromatic characteristics, considering both the effects of the (individual) barrel and cooperage. A red wine was aged in 49 new medium-toasted oak (Quercus petraea) barrels, from four cooperages, for 12 months

Mannoproteins (MPs) are proteoglycans from the outmost layer of yeast cell walls released into wine during alcoholic fermentation and ageing on lees processes. The use of commercial preparations of mannoproteins as additives to improve wine stability with regards to the crystallization of tartaric salts and to prevent protein haze in the case of white and rosé wines is authorized by the OIV.
Regarding red wines and polyphenols, mannoproteins are described as able to improve their colloidal stability and modulate the astringent effect of condensed tannins. The latter interact with salivary proteins forming insoluble aggregates that cause a loss of lubrication in the mouth and promote a drying and puckering sensation. However, neither the interaction mechanisms involved in mannoproteins capacity to impact astringency nor the structure-function relationships related to this property are fully understood.