Effect of indigenous S. cerevisiae strains on higher alcohols, volatile acids and esters in wine

Abstract

Furdíková K., Makyšová K., Špánik I. (2017): Effect of indigenous S. cerevisiae strains on higher alcohols, volatile acids, and esters in wine. Czech J. Food Sci., 35: 131-142.Higher alcohols, volatile fatty acids, and esters are the most important volatiles and their formation is closely related to yeast strains employed during fermentation. In the present work, the effect of indigenous yeast strains on selected wine volatiles was examined using a highly sophisticated analytical method -comprehensive two-dimensional gas chromatography. Results of the statistical analysis revealed that each strain could be characterised and differentiated according to its volatile composition: strain Y2 was characterised by 2-phenylethanol and 1-hexanol, strain Y1 was in close relationship with high amounts of 4-methyl-1-pentanol, iso-amyl alcohol, ethyl 3-hydroxypentanoate and 3-methylpentanoic acid and strain Y3 was associated with 1-heptanol, cis-3-hexen-1-ol, β-phenylethyl butyrate, octanoic, and decanoic acids. The selection of an appropriate yeast strain thus represents a critical variable affecting the analysed volatile compounds (wine flavour) not only in a qualitative but also in a quantitative way.

Evaluation of Volatile Compounds during Ageing with Oak Chips and Oak Barrel of Muscat Ottonel Wine

“…The appearance of this compound depended on all factors (ageing duration, chips types and ageing method). Phenyl acetate which gives wines a rose, fruity and tobacco note [30], was detected in higher amounts after ageing, compared with the initial wine (228 µg/L). According to Table 2, this compound recorded higher amounts in untoasted oak chips (730 µg/L) and untoasted barrel (623 µg/L) wine samples.…”

“…Between the major alcohols, isoamyl alcohol was the most abundant, with the concentrations of 55 mg/L in initial wine. This alcohol gives a cheesy note to the wine, and have an odour threshold of 30 mg/L [30], so in this case, may contribute to the aromatic profile. After 30 days of ageing, the concentration of this alcohol dropped to 54 mg/L (untoasted chips), 53 mg/L (light toasted chips) and 49 mg/L (untoasted barrels).…”

“…At the end of ageing period (90 days), the amount of isoamyl alcohol slightly increased. The 2-phenylethanol with flowery, pollen, and perfumed notes [30] was found in 22 mg/L content in the initial wine. After 30 days ageing, the content in this compound decreased.…”

“…The type of oak chips and ageing method did not significantly influence isoamyl alcohol, iso-butanol, and 2-phenylethanol concentration. Alcohols with minor abundance: 1-heptanol, E-3-hexenol, Z-3-hexenol, and 2-nonanol bring predominantly green aroma tones, while higher saturated alcohols, like benzyl alcohol, are responsible for citrus-like smells [30]. The changes of minor alcohols observed during ageing may be set in three trends.…”

Comparative transcriptional analysis of flavour-biosynthetic genes of a native Saccharomyces cerevisiae strain fermenting in its natural must environment, vs. a commercial strain and correlation of the genes’ activities with the produced flavour compounds

“…As Sipiczki reported, over the last 30 years, a large number of studies have proved that S. cerevisiae wine-producing strains exhibit a very high degree of diversity, differing significantly in both the genotype and their oenological capacities (phenotype) [19]. The indigenous S. cerevisiae strains, which are representatives of the microflora of vines and local wineries, are considered as a good source for isolating strains with desirable oenological characteristics [20], able to produce wines of stylistic distinction, uniqueness and originality, characteristic of the geographical region of origin ( terroir ) [1, 21]. However, the relationship of these wild-type genotypes, linked to specific terroirs , with the biosynthetic profiles of flavour metabolites is not completely clarified and understood [22].…”