Karine Primieri Nicolli

Monitoring the evolution of volatile compounds using gas chromatography during the stages of production of Moscatel sparkling wine

This study reports, for the first time, the main changes that occur with some important aroma compounds of Moscatel sparkling wines during winemaking, measured using headspace solid-phase microextraction, one-dimensional and comprehensive two-dimensional gas chromatography (GC×GC) with mass spectrometry detection (MS). The best conditions of volatile extraction included the use of PDMS/DVB fibre, 2mL of wine, 30% of NaCl, 40°C for 30min. The chromatographic profile of sparkling wines showed decreasing amounts of monoterpenes (limonene, 4-terpineol, terpinolene, citronellol, α-terpineol, linalool, hotrienol, and nerol oxide), increasing amounts of esters (terpenyl esters, ethyl octanoate, ethyl decanoate and hexyl acetate) and alcohols (1-nonanol and 2-phenylethanol). Sixty-nine compounds co-eluted in the first dimension; only six co-eluted in the second dimension. GC×GC/TOFMS allows more detailed study of the volatile profile of sparkling wines.

Influence of ripeness and maceration of the grapes on levels of furan and carbonyl compounds in wine – Simultaneous quantitative determination and assessment of the exposure risk to these compounds

The validated method based on the use of headspace solid phase microextraction (HS-SPME) coupled with the comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GC×GC/TOFMS) proved to be appropriate for this first simultaneous quantitative determination of six toxic compounds (formaldehyde, acetaldehyde, ethyl carbamate, furan, furfural and acrolein) found in wines. Acetaldehyde and acrolein coeluted with other wine compounds, which indicated that difficulties could arise if only one-dimensional gas chromatography was used for the determination of these compounds. The advancement of the ripeness degree and increasing the grape maceration time seems to result in higher concentrations of toxic compounds. The exposure to furan, acrolein and ethyl carbamate through wine consumption may pose risks to consumer health, since calculated MOE values were lower than 10,000.

Sensory, olfactometry and comprehensive two-dimensional gas chromatography analyses as appropriate tools to characterize the effects of vine management on wine aroma

For the first time, the influence of different vine management was evaluated in relation to volatile profile and sensory perception through GC×GC/TOFMS, QDA, GC-FID, GC/MS, and GC-O. GC×GC/TOFMS analyses and QDA have shown that a larger spacing between vine rows (2 rather than 1m), attachment of shoots upwards, and irrigation did not result in wine improvement. Conversely, wines elaborated with grapes from a vine with a lower bud load (20 per plant; sample M1) stood out among the other procedures, rendering the most promising wine aroma. GC×GC/TOFMS allowed identification of 220 compounds including 26 aroma active compounds also distinguished by GC-O. Among them, eight volatiles were important to differentiate M1 from other wines, and five out of those eight compounds could only be correctly identified and quantified after separation in second dimension. Higher levels of three volatiles may explain the relation of M1 wine with red and dry fruits.

Characterization of the Volatile Profile of Brazilian Moscatel Sparkling Wines Through Solid Phase Microextraction and Gas Chromatography

Solid phase microextraction, one-dimensional gas chromatography (1D-GC) and comprehensive two-dimensional gas chromatography (GC×GC) with mass spectrometric detector have been used to characterize the volatile profile of Moscatel sparkling wines. Predominant classes were esters, acids, alcohols and terpenes. The efficiency of GC×GC was apparent due to the higher number of compounds positively and/or tentatively identified through this technique (two and a half times higher than with 1D-GC), as well as by the separation of co-eluted compounds in 1D-GC. Principal components analysis showed that the volatile profile of the majority of sparkling wines is similar. Only two samples differed from others and the compounds responsible for this behavior were nerol, menthol, linalool acetate, limonene and geraniol. Furthermore, a clear separation among sparkling wines done with two Moscato grape varieties (Bianco and Giallo) was observed in cluster analysis due to the higher chromatographic area of terpenes and norisoprenoids verified in Giallo samples.

Analysis of Volatile Compounds of Leaves and Galls of Schinus polygamus and Baccharis spicata by Headspace Solid-Phase Microextraction

Abstract Headspace Solid-Phase Microextraction (HS-SPME) is presented as an efficient tool to access differences and similarities in the composition of volatiles that might have been caused by insect-plant interaction, using leaves and galls of Schinus polygamus and Baccharis spicata. Method development involved testing nine SPME coatings, resulting in the choice of the triple layer divinylbenzene-carboxen-polydimethylsiloxane (DVB-CAR-PDMS). Qualitative and quantitative differences between distinct plant tissues and also between hydrodistilled oil and headspace chromatographic profile of the same sample confirmed that HS-SPME is a convenient analytical tool to provide information closer to that of the plant in vivo on possible allelochemicals of different plant tissues involved in the insect-plant interaction.

Preliminary investigation of medicinal herb adulteration using comprehensive two-dimensional gas chromatography and chemometric analysis

Anise is frequently found among the ingredients described in the label of cosmetic products. However, the use of fennel instead of anise may occur due to the lower price of fennel. The main differences in volatile profile of anise and fennel fruits were, for the first time, evaluated using comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GC×GC/TOFMS) and chemometric analysis. Aproximately 950 peaks were found in chromatograms of each sample and Fisher ratio appointed 31 volatile analytes as the most discriminating between anise and fennel samples. These 31 compounds were used in principal component analysis and canonical discriminant analysis that designated seven compounds (estragole, methyl eugenol, 4,5-dehydro-isolongifolene, calamenene, linalool, β-ocimene and fenchol) as the most important to verify the use of fennel or anise in personal care products. Among these seven compounds, thrree coeluted with other compounds and were correctly identified only with the use of GC×GC/TOFMS.

Volatile Profile of Sparkling Wines Produced with the Addition of Mannoproteins or Lees before Second Fermentation Performed with Free and Immobilized Yeasts

Heat map and hierarchical cluster analysis showed that sparkling wines produced with immobilized yeasts contained mostly higher levels of compounds that impart positive notes to wines. Fisher ratio pointed out nine volatile compounds as the main components responsible for differentiation of samples treated with mannoproteins/lees and others. Principal component analysis (PCA) showed differences between the sparkling wines produced with and without adjuvants (commercial mannoproteins or lees). Sparkling wines aged without adjuvants presented higher levels of decanoic and dodecanoic acids (fatty/metallic aroma), while the use of mannoproteins or lees resulted in higher content of some fruity esters, nerolidol and β-damascenone. Therefore, the combination of immobilized yeast and aging on mannoproteins or lees seems to be the most promising treatment to obtain the volatile profile that positively influence wine quality.