Outlining the influence of non‐conventional yeasts in wine ageing over lees

Abstract

During the last decade, the use of innovative yeast cultures of both Saccharomyces cerevisiae and non-Saccharomyces yeasts as alternative tools to manage the winemaking process have turned the oenology industry. Although the contribution of different yeast species to wine quality during fermentation is increasingly understood, information about their role in wine ageing over lees is really scarce. This work aims to analyse the incidence of three non-Saccharomyces yeast species of oenological interest (Torulaspora delbrueckii, Lachancea thermotolerans and Metschnikowia pulcherrima) and of a commercial mannoprotein-overproducer S. cerevisiae strain compared with a conventional industrial yeast strain during wine ageing over lees. To evaluate their incidence in mouthfeel properties of wine after 4 months of ageing, the mannoprotein content of wines was evaluated, together with other wine analytic parameters, such as colour and aroma, biogenic amines and amino acids profile. Some differences among the studied parameters were observed during the study, especially regarding the mannoprotein concentration of wines. Our results suggest that the use of T. delbrueckii lees in wine ageing is a useful tool for the improvement of overall wine quality by notably increasing mannoproteins, reaching values higher than obtained using a S. cerevisiae overproducer strain.

The impacts of Lachancea thermotolerans yeast strains on winemaking

“…The use of L. thermotolerans in aging over lees has been reported as not producing higher final concentrations of mannoproteins than the S. cerevisiae control after 4 months; as expected, the S. cerevisiae control produced approximately 50% more mannoproteins expressed in mannose concentration (Belda et al 2016).…”

“…Other biogenic amine precursors, such as ornithine and tyrosine also slightly increased after fermentations involving L. thermotolerans (Benito et al 2015a;Benito et al 2016b). With "on the lees" aging of greater than 4 months, L. thermotolerans wines released higher concentrations of histidine, tyrosine, ornithine, and lysine than the S. cerevisiae controls, although no differences were observed in the final biogenic amine concentrations (Belda et al 2016). There is no direct relationship between the precursor amino acids of the biogenic amines and the formation of biogenic amines as the result of microbial decarboxylation (e.g., from lactic acid bacteria).…”

The Influence of Non-Saccharomyces Species on Wine Fermentation Quality Parameters

“…Mannoproteins represent the second most abundant group; however, these polysaccharides are formed during alcoholic fermentation or ageing during lees processes [26,47]. Although the first microbiological applications for increasing the content of mannoproteins in wines were based on the use of S. cerevisiae strains, later studies showed that some non-Saccharomyces species release higher concentrations of mannoproteins than S. cerevisiae [47][48][49][50]. Other polysaccharides of a different nature than mannoproteins are also reported for some non-Saccharomyces species [26,[51][52][53].…”

“…Nevertheless, the acidification performed by L. thermotolerans can partially inhibit the capacity of unselected lactic bacterial strains to produce biogenic amines, as the development of lactic bacterial genera is limited at low pH values. This potential food safety problem is also present when L. thermotolerans is used in ageing over lees for histidine, tyrosine, ornithine, and lysine amino acids [49].…”

Effect of the inoculation strategy of non-Saccharomyces yeasts on wine malolactic fermentation

“…Thus, a new trend in winemaking uses mixed starter cultures of non-Saccharomyces and S. cerevisiae (Belda et al, 2015;Ciani et al, 2010) or a sequential inoculation of S. cerevisiae after non-Saccharomyces (Contreras et al, 2014;González-Royo et al, 2015). Among the different species of non-Saccharomyces, Torulaspora delbrueckii and Metschnikowia pulcherrima show the most promising results for global wine quality, such as low production of volatile acidity (Renault et al, 2009) or a notable mannoprotein release ability, which increases the mouthfeel properties of wine (Belda et al, 2016).…”