Non-Saccharomyces yeasts play a substantial role in the early stages of wine fermentation. With the increase in alcohol concentration, indigenous or commercial strains of Saccharomyces cerevisiae take over and complete the transformation of the grape must sugars into ethanol, CO2, and other secondary metabolites. The presence of non-Saccharomyces during the fermentation has an impact on the wine composition, and consequently, their contribution during the fermentation process cannot be ignored. The new challenges to enhance the appeal and value of wine elaborated by traditional technology are being achieved by selecting and using autochthonous non-Saccharomyces and Saccharomyces strains that may enhance regional identity of wines. Greater understanding of yeast biochemistry and physiology is enabling the selection and development of yeast strains that have defined specific influences on process efficiency and wine quality. The aim of this chapter was to show the different aspects of non-Saccharomyces species that may play a positive incidence in the biotechnological process to conduct to wine elaboration.
Part of the book: Grape and Wine Biotechnology
The effects of prefermentative cold skin-contact technique using Malvasia aromatica were studied as a first step to adapt to the climate change related effects in order to intensify the aroma potential of white wines of the D.O. “Vinos de Madrid” keeping the organoleptic characteristics of the region. Major volatile compounds were extracted by liquid–liquid extraction and quantified by GC-FID. Minor volatile compounds were determined by HS-SPME/GC–MS. Sensory analysis were also carried out to describe and quantify attributes of the wines. A total of 37 components were identified and quantified. Volatile components showed mixed behavior depending on the skin-contact time. Skin-contact for longer helps to enhance the floral character provided by some compounds contained in the skin, especially linalool and 2-phenyl etanol and were impact odorants of Malvasia aromatica wine based on odor activity values (OAVs).
Part of the book: Grapes and Wine
The loss of aromatic and sensory quality in wines because of climate change in traditional winemaking areas is a challenge for winemakers. Aging on lees of the wine fermented with Saccharomyces native yeasts has been tested as a technique to try to improve the sensory characteristics of Malvasia aromatica white wines in PDO “Vinos de Madrid.” The grapes were pre-cold macerated and fermented with S. cerevisiae CLI 271 and CLI 889 (native yeast strains). Then, commercial lees were used for aging of wines for a five-month at low temperature in order to compare with the effect of S. cerevisiae CLI 271 and CLI 889 without lees treatment. Aromatic and organoleptic properties of wines aged on lees were studied using GC-FID and HS-SPME/GC–MS to quantify volatile compounds and a taster panel to sensorial analysis. There was a significant decrease in the ester family in wines aged on lees being more pronounced in CLI 889 wines. The treatment contributed to enhance the fruity and floral aromatic properties in CLI 271 and CLI 889 wines, respectively according to tasting panel, which showed a hedonic preference for CLI 271 wines without lees treatment and CLI 889 wines aged on lees.
Part of the book: New Advances in Saccharomyces
Beer is a world-famous beverage, second only to tea and coffee, where the yeasts traditionally used are Saccharomyces cerevisiae and Saccharomyces pastorianus for the production of ale and lager beer, respectively. Their production, especially craft beer production, has grown in recent years, as has the development of new products. For this reason, research has focused on the selection of yeasts with good fermentation kinetics, as well as beers with outstanding aromatic profiles. The final flavor and aroma of beer is a combination of hundreds of active aroma compounds produced mostly during fermentation as a result of yeast metabolism (higher alcohols, esters, aldehydes, and vicinal diketones). Likewise, several studies have demonstrated the potential of wild yeasts of the genus Saccharomyces, both in aromatic production and in the production of healthy compounds of interest such as melatonin. This chapter therefore focuses on non-conventional Saccharomyces yeasts as they have the capacity to produce outstanding aroma compounds, as well as compounds that can provide health benefits, under moderate consumption.
Part of the book: New Advances in Saccharomyces