Headspace solid-phase microextraction–gas chromatography–mass spectrometry for profiling free volatile compounds in Cabernet Sauvignon grapes and wines

Optimisation of solid-phase microextraction combined with gas chromatography–mass spectrometry based methodology to establish the global volatile signature in pulp and skin of Vitis vinifera L. grape varieties

“…(E)-2-hexenal and hexanal), which found to be the major constituent of the skin and pulp of both investigated varieties. These compounds, products of the enzymatic breakdown of unsaturated fatty acids, when present at concentration above its OT, can contribute with herbaceous notes, while nonanal and decanal could exhibit soapy, citrus-like and green notes [3,64], respectively.…”

“…As in many food products, grape and wine aroma is influenced by the action of hundreds of VOCs and SVOCs belonging to different chemical groups, namely mono and sesquiterpenoids, C 13 norisoprenoids, alcohols, acids, carbonyl compounds, sulphur compounds, pyrazines, among others [3][4][5]. They have a considerable influence on the sensorial complexity of grapes, and consequently of juices and wines covering a wide range of polarities, volatilities, and concentrations.…”

“…These compounds, which are secondary products of the plant metabolism, were found to be distributed through the different parts of the berry, namely pulp and skin, which depend on the variety. Several studies show that these compounds were found predominantly in skin tissue and typically stored as sugar or amino acid conjugates in the vacuoles of the exocarp cells [3]. Bayonove et al [8] observed a highly uneven distribution of some free monoterpenes in different fractions of Muscat grapes.…”

“…SPME methodology provides a suitable tool for organic analytical chemistry because is a fast, simple and sensitive procedure which offers important advantages as it eliminates the use of organic solvents and allows to combine sampling, extraction and concentration into a single step, and substantially shortening analysis time [16]. For these reasons, SPME applications in food analysis are vast, and recently have been successfully applied to study the volatile composition of grapes [3,[17][18][19][20][21][22], and wines [23][24][25]. Nevertheless, in these studies few extraction-influencing parameters were taken into account.…”

“…Nevertheless, in these studies few extraction-influencing parameters were taken into account. For example, only two SPME fibre coatings, at two extraction times (30 and 60 min) and two temperatures (40 and 50 • C) have been used for the optimisation of HS-SPME methodology to profile the volatile composition in Cabernet Sauvignon grapes by Canuti et al [3]. In order to obtain a reliable methodology to study grape VOCs and SVOCs, Sánchez-Palomo et al [20] tested three fibre coatings, and different extraction times (10,20,30,40 and 50 min) and temperatures (40,50,60 and 70 • C), while Kalua and Boss [19] focused their study on the grapes dilution solvent, and sample/headspace volume optimisation.…”