Comparison of Different Categories of Slovak Tokaj Wines in Terms of Profiles of Volatile Organic Compounds

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).

Quantification of Volatile Compounds in Wines by HS-SPME-GC/MS: Critical Issues and Use of Multivariate Statistics in Method Optimization

“…As it cannot be usually expected that the IS behaves the same as all of the analytes and, indeed, this requisite is generally not verified, quantification based on an IS is considered a semi-quantitative method. However, this approach is simple, versatile and can be successfully used when just a comparison of the number of individual compounds among samples is desired [50,51]. As the conversion of the analyte/IS response ratio into the analyte concentration can be misleading, many authors have expressed their results as a chromatographic peak area percentage for each volatile in order to compare it among the studied treatments [52,53].…”

Indicators of change in cultural heritage. Monograph

“…Cibebas, compared to healthy (uninfected) grape berry, differs in visual appearance as well as in chemical composition. Noble botrytization causes a relevant increase of sugars in berry accompanied by an increase of glycerol, ethanol, citric, gluconic, and succinic acid concentration [Furdíková et al 2020].…”

“…The grapes are harvested in late October and November. In particular, grape berries infected with Botrytis cinerea Persoon are harvested, which, through its metabolism, significantly interferes with the physiology of the berries, increases the sugar content, changes the chemical composition and creates a sensory expression of the berries [Furdíková et al 2020]. These noble-rotten grape berries, called 'cibebas' , are concentrated in vats.…”

Role of gas chromatography and olfactometry to understand the wine aroma: Achievements denoted by multidimensional analysis

“…The presence of γ‐octalactone and 6‐methylhept‐2‐en‐4‐one was typical of Tokajské samorodné dry. Tokaj selections were expressed by the highest level of diethyl malate, benzaldehyde, and furfurals [133].…”