Effects of Soil and Vineyard Characteristics on Volatile, Phenolic Composition and Sensory Profile of Cabernet Sauvignon Wines of Campanha Gaúcha

Abstract

The influence of vineyard on wines was evaluated for the first time using a broader analytical approach: sensory analyses and several analytical techniques (gas chromatography-mass spectrometry (GC-MS), GC flame ionization detection (FID), GC-olfactometry-Osme technique (GC-O-Osme), GC × GC-MS), taking into account odoriferous compounds of Cabernet Sauvignon wines. Sensory attributes were correlated to the concentration of volatiles and also to favorable climate/solar exposition, less clayey/lower organic matter soil, and lower vegetative growth of one out of five vineyards, C1. Among 30 coelutions in GC-MS, 12 involved some of the odoriferous volatiles and GC × GC-MS was required to elucidate their identities. Higher concentrations of ethyl propanoate and diacetyl (related with red fruits/aromatic intensity) and of acetoin (aroma of dry fruits, but coeluted with octanal in first dimension (1 D), which presents green odor) were found in C1 wine. It was also correlated with positive appearance attributes, gustatory persistence, body, smell and taste harmony, as well as with higher concentrations of phenolic acids, anthocyanins, flavonols, stilbenes, and flavanols.

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

“…In order to obtain suitable reliability, when a low number of assessors are involved, the number of repetitions per assessor is usually greater and vice versa as presented in Figure 1 [30]. For example, in OSME GC‐O analysis of Muscadine wines was performed by two assessors with at least five repetitions of each sample [17], whereas five judges evaluated Cabernet Sauvignon wines doing three repetitions [23] and four panelists performed four repetitions per sample of Pinot Noir [97], Syrah [27], and Merlot [26] wines. For all GC‐O methods, data collected by each panelist and considering the repetitions performed for each sample are averaged, yielding a consensus odorgram as represented in Figure 2.…”

“…1DGC is predominantly used for the evaluation of odorous compounds in wines (73% of the studies reported in Table 1). Nevertheless, due to the complex volatile profile of wine, the separation capacity of the 1DGC was found to be insufficient and the MDGC has emerged as an important tool to improve the chromatographic separation of important compounds for the wine aroma [22–25,27].…”

“…Scheme of proposals for combining olfactometry with 1DGC, GC‐GC and GCxGC. (A) GC‐GC‐O‐FID/MS system showing the coupling of chromatograph 1 (GC1) to the flame ionization detector (FID) and to the olfactometer and chromatograph 2 (GC2) to the mass spectrometry (MS) and olfactometric detectors [22,24,25,56,65,82,84,86]; (B) GCxGC/MDGC‐O‐FID/MS with first chromatographic dimension ( 1 D) coupled to a long ( 2 D L , 30 m) and a short column ( 2 D S , 0.9 m) in the second dimension [10]; (C) polydimethylsiloxane (PDMS) trap collects specific fractions of the 1DGC to be evaluated by an off‐line olfactometer and GCxGC/MS [44]; (D) GC‐O/GCxGC‐FID system in parallel to GC×GC/MS [11]; (E) Affinity chromatography and GC with sulfur chemiluminescence detector (GC−SCD), and GCxGC/MS to evaluate sulfur‐containing compounds [5]; (F) GC‐O/MS in parallel to GCxGC/MS to quantify odor‐active compounds [70]; (G) GC‐O‐FID/MS in parallel to GCxGC/MS to identify and quantify odor‐active compounds and to elucidate the entire volatile profile of wine [23,26,27]…”

“…The fundamental purpose of using GCxGC combined with GC‐O is to resolve coelutions of active‐active compounds [10,11,44,61,70]. However, some studies have also used the potential of the GCxGC to comprehensively assess the volatile profile of wines in addition to studying the odor‐active compounds [23,26,27]. Table 3 shows the odor‐active compounds involved in coelutions found using the different configurations of olfactometry combined with GCxGC/MS.…”

“…There are several reasons why an appropriate chromatographic resolution is an important goal in wine analysis and some of them may be mentioned: searching for markers for denomination of origin, preventing adulteration, differentiating grape cultivars, aging types, yeasts, processes of vinification, among others [19–21]. An analytical approach encompassing multiple dimensions, such as multidimensional GC (MDGC), including heart‐cutting GC (GC‐GC) or comprehensive two‐dimensional GC (GCxGC), may help separating coeluting compounds and detect some trace compounds important to wine aroma [22,23]. GC techniques combined with olfactometry have been used to identify odor‐active compounds that are essential to differentiate wines according to the terroir [24], to understand the role of fungal infection of grapes for wine quality [25], to find best canopy management practices [26] and to define the ideal balance between maturation degree and maceration time of grapes to obtain the best quality [27], among others.…”