No abstract

Bénes I., Furdíková K., Šmogrovičová D. (2015): Influence of Saccharomyces cerevisiae strain on the profile of volatile organic compounds of blossom honey mead. Czech J. Food Sci., 33: 334-339.The influence of yeast strain on the volatile profile of meads fermented from blossom honey using three different saccharomyces cerevisiae var. bayanus strains was evaluated. Meads were analysed by methods of basic chemical analysis and gas chromatography after 15 days of fermentation. Individual yeast strains produced various metabolites in different concentrations under the same fermentation conditions which significantly influenced the final secondary aroma of mead. Higher concentrations of acetaldehyde and 1-propanol, associated with s. cerevisiae var. bayanus MM-R2 considerably distinguished this strain from the others, whereas the difference between strains s. cerevisiae var. bayanus FM-R-Fix1 and MT-R1B was characterised by the production of ethyl hexanoate, ethyl octanoate (FM-R-Fix1), and isobutyl alcohol (MT-R1B).

No abstract

The present work deals with the characterization of volatile organic compounds (VOCs) in wines from the Slovak Tokaj wine region. Studied wine samples were divided into three groups—varietal wines from registered Tokaj vine varieties, film wines Tokajské samorodné dry, and naturally sweet botrytized wines Tokaj selections. The VOCs from wines were extracted using optimized solid phase microextraction (SPME) and analyzed by comprehensive two-dimensional gas chromatography (GC×GC) coupled to high-resolution time-of-flight mass spectrometry (HRTOF-MS). In total, 176 VOCs were identified in all 46 studied samples. It was found that the total number of VOCs in varietal wines was generally higher than in botrytized wines. All three studied categories showed characteristic VOC profiles with significant differences. Varietal wines were characterized by higher concentrations of esters and terpenoids originating from grapes. The presence of γ-octalactone, (E)-6-methylhept-2-en-4-one, and lack of benzaldehyde were typical for Tokajské samorodné dry. Tokaj selections expressed the highest concentration of diethyl malate, benzaldehyde, and furfurals. Several interesting trends were also observed. The concentration of fermentation products was highest in varietal wines, while long-term matured Tokaj special wines were typified by the presence of compounds related to noble-rotten raisins (2-phenylacetaldehyde, ethyl 2-phenylacetate, and 2-phenylethanol), wood (cis-whisky lactone), and aging (1,1,6-trimethyl-2H-naphthalene, furfural, and 5-methylfurfural).

AbstractŠevcech J., Vicenová Ľ., Furdíková K., Malík F. (2015): Influence of thermal treatment on polyphenol extraction of wine cv. André. Czech J. Food Sci., 33: 91-96.The extraction of polyphenols and colour parameter development of the grape variety André processed by thermal maceration techniques were examited. Comparing four different thermal maceration processes we have found out that the cold soak combined with classical maceration had the most significant effect on the extraction of total polyphenols and anthocyanins. Concentration of total phenols was more than 27% higher than in a thermovinificated sample. These techniques have also offered wines with the highest colour intensity. There was no considerable influence of maceration on the main products of ethanol fermentation but an effect on the concentration of total acids in wine was observed. In all cases fermentation caused a decrease of total phenols in André wines.

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.

No abstract

No abstract