Abstract
Winemaking is a highly industrialized process and a number of commercial Saccharomyces cerevisiae strains are used around the world, neglecting the diversity of native yeast strains that are responsible for the production of wines peculiar flavours. The aim of this study was to in-depth establish the S. cerevisiae volatile metabolome and to assess inter-strains variability. To fulfill this objective, two indigenous strains (BT2652 and BT2453 isolated from spontaneous fermentation of grapes collected in Bairrada Appellation, Portugal) and two commercial strains (CSc1 and CSc2) S. cerevisiae were analysed using a methodology based on advanced multidimensional gas chromatography (HS-SPME/GC×GC-ToFMS) tandem with multivariate analysis. A total of 257 volatile metabolites were identified, distributed over the chemical families of acetals, acids, alcohols, aldehydes, ketones, terpenic compounds, esters, ethers, furan-type compounds, hydrocarbons, pyrans, pyrazines and S-compounds. Some of these families are related with metabolic pathways of amino acid, carbohydrate and fatty acid metabolism as well as mono and sesquiterpenic biosynthesis. Principal Component Analysis (PCA) was used with a dataset comprising all variables (257 volatile components), and a distinction was observed between commercial and indigenous strains, which suggests inter-strains variability. In a second step, a subset containing esters and terpenic compounds (C10 and C15), metabolites of particular relevance to wine aroma, was also analysed using PCA. The terpenic and ester profiles express the strains variability and their potential contribution to the wine aromas, specially the BT2453, which produced the higher terpenic content. This research contributes to understand the metabolic diversity of indigenous wine microflora versus commercial strains and achieved knowledge that may be further exploited to produce wines with peculiar aroma properties.
Highlights
Winemaking is a highly industrialized process and different Saccharomyces cerevisiae starter cultures are commercially available for its control and fermentation homogeneity
Two indigenous strains and two of the mostly used commercial strains (CSc1 and CSc2) of S. cerevisiae were analysed using high sensitive and high throughput methodology based on two dimensional gas chromatography (GC×GC)
The full data matrix is provided as Supplementary Data (S1 Table), which presents the information obtained for each of the 257 compounds tentatively identified, including the retention times in both dimensions, GC peak areas, RSD, and retention index experimentally calculated (RIcal) and available in the literature for a 5% phenyl polysilphenylene-siloxane GC column or equivalent (RIlit)
Summary
Winemaking is a highly industrialized process and different Saccharomyces cerevisiae starter cultures are commercially available for its control and fermentation homogeneity. Their dominant growth reduce the development of indigenous species potentially detrimental and, as a consequence, decrease the risk of wine spoilage [1,2,3]. The use of a “microarea-specific” starter culture has shown that the volatile profile of wine is strictly related to the geographical origin of the yeast employed used on the fermentation process [9]. Previous studies suggested that some yeasts volatile metabolites, such as alcohols, esters and organic acids have impact on wine character [2,11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
