Data on changes in red wine phenolic compounds, headspace aroma compounds and sensory profile after treatment of red wines with activated carbons with different physicochemical characteristics

Data in this article presents the changes on phenolic compounds, headspace aroma composition and sensory profile of a red wine spiked with 4-ethylphenol and 4-ethylguaiacol and treated with seven activated carbons with different physicochemical characteristics, namely surface area, micropore volume and mesopore volume (“Reduction of 4-ethylphenol and 4-ethylguaiacol in red wine by activated carbons with different physicochemical characteristics: impact on wine quality” Filipe-Ribeiro et al. (2017) [1]). Data on the physicochemical characteristics of the activated carbons are shown. Statistical data on the sensory expert panel consistency by General Procrustes Analysis is shown. Statistical data is also shown, which correlates the changes in chemical composition of red wines with the physicochemical characteristics of activated carbons used.


a b s t r a c t
Data in this article presents the changes on phenolic compounds, headspace aroma composition and sensory profile of a red wine spiked with 4-ethylphenol and 4-ethylguaiacol and treated with seven activated carbons with different physicochemical characteristics, namely surface area, micropore volume and mesopore volume ("Reduction of 4-ethylphenol and 4-ethylguaiacol in red wine by activated carbons with different physicochemical characteristics: impact on wine quality" Filipe-Ribeiro et al. (2017) [1]). Data on the physicochemical characteristics of the activated carbons are shown. Statistical data on the sensory expert panel consistency by General Procrustes Analysis is shown. Statistical data is also shown, which correlates the changes in chemical composition of red wines with the physicochemical characteristics of activated carbons used.

Experimental features
Activated carbons adsorption isotherms were analysed by gas adsorption and mercury porosimetry, surface groups were analysed by FTIR.
Wine phenolic acids and anthocyanins were analysed by RP-HPLC with a photodiode array detector and headspace aroma compounds were analysed by headspace solid phase microextraction using a 50/30 μm DVB/Carboxen/PDMS fibre followed by GC-MS using an Optima FFAP column (30 m Â 0.32 mm, 0.25 μm). Sensory analysis was performed by an expert panel of six experts.

Vila Real, Portugal
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Value of the data
Data from this research highlights the effect of the physicochemical characteristics of activated carbons on the phenolic, headspace aroma and sensory profile of wines spiked with 4-ethylphenol and 4-ethylguaiacol.
We analysed the phenolic profile by RP-HPLC and the aroma compounds by HS-SPME-GC/MS in red wines treated with activated carbons presenting different physicochemical characteristics and the results were analysed by principal component analysis for highlighting relations between chemical composition of red wines and physicochemical characteristics of activated carbons.
Activated carbons removal efficiency of red wine ethylphenols was related to their surface area and micropore volume.
High surface area of mesopores and total pore volume were important for the anthocyanin removal and decrease in colour intensity.
This data could serve as a benchmark for other researchers, evidencing the influence of activated carbons treatment on the individual phenolic, chromatic and aroma compounds and sensory profile of red wine.

Data
The data reported includes information about the adsorption isotherms of activated carbons (ACs) (Fig. 1), metal composition of activated carbons (Table 1) and surface group chemistry of activated carbons ( Fig. 2 and Table 2). Also the sensory profile of wines (Fig. 3a) and consistency of the sensory panel scores were analysed by General Procrustes Analysis (GPA) (Fig. 3b and Table 3) and the scaling factor of each expert were determined ( Table 4). The headspace aroma profile of red wines before and after treatment with activated carbons were determined (Table 5) and the reduction of total aroma compounds and reduction of each class of chemical compounds were calculated (Fig. 4). The headspace aroma compounds decrease and structural characteristics of each aroma compound were correlated (Table 6 and Fig. 5). The phenolic composition (total phenols, flavonoid phenols, nonflavonoid phenols, total anthocyanins) and colour properties (colour intensity, hue and chromatic characteristics) of treated and untreated wines were determined ( Table 7). The phenolic profile of wines were determined by RP-HPLC that included the phenolic acids and flavonoids (Table 8) and monomeric anthocyanins ( Table 9). The relation between aroma abundance and the activated carbons physicochemical characteristics were analysed by principal component analysis (Fig. 6a) and between the phenolic compounds content and activated carbons physicochemical characteristics (Fig. 6b).

Wine sample
A red wine from Douro Valley (vintage 2013) was used in this work, their main characteristics were follows: alcohol content 13.4% (v/v), specific gravity (20°C) 0.9921 g/mL, titratable acidity 5.1 g/L expressed as tartaric acid, pH 3.84, volatile acidity 0.50 g/L expressed as acetic acid.

Analysis of conventional oenological parameters
Alcohol, specific gravity, pH, titratable acidity and volatile acidity were analysed using a FTIR Bacchus Micro (Microderm, France).

Experimental design
The addition of 4-ethylphenol and 4-ethylguaiacol was carried out on the red wine sample at the highest concentrations found in literature, 1500 μg/L for 4-ethylphenol and 300 μg/L for 4ethylguaiacol (4-EP1500 and 4-EG300) [18] and were also prepared at medium level of contamination with 750 mg/L of 4-ethylphenol and 150 mg/L of 4-ethylguaiacol (4-EP750 and 4-EG150). Seven solid commercial activated carbons, characterized by [1], were used: C1 (powder), C2 (powder), C3 (powder), C4 (powder), C5 (powder), C6 (granulated) and C7 (powder). The activated carbons were next added at 100 (g/hL) maximum dosage authorized [19] to the wine placed in 250 mL graduated cylinders. After 6 days the wines were removed from graduated cylinders and then were centrifuged at 10,956g, 10 min at 20°C in order to be analysed. All the assays and analyses were performed in duplicate.

Colour and total anthocyanins
Colour intensity and hue was determined by measuring absorbance at 420 nm, 520 nm and 620 nm (1 mm cell) according to [20]. The content of total anthocyanins was determined according to [21].

Chromatic characterization
The chromatic characteristics of wines calculated using the CIELab method according to [20]). The colour difference was calculated using the following equation: ΔE*¼[(ΔL*) 2 þ (Δa*) 2 þ(Δb*) 2 ] 1/2 . Table 3 Procrustes Analysis of Variance (PANOVA) [5] of the sensory aromatic, taste and tactile/textural attributes data of volatile phenols free (T0) and volatile phenols spiked (TF) red wine and after treatment with different activated carbons (C1 to C7).     Results expressed in absolute area (area*10 5 ). Values are presented as mean7 standard deviation; $ ID -Identification; std -Standard; * RI (retention index) from: [6][7][8]. MW (molecular weight). ODT (olfactory detection threshold). Odour descriptor from: [9][10][11]. Means within a column followed by the same letter are not significantly different ANOVA and Tuckey post-hoc test (po 0.05). n.d., not detected; volatile phenols free (T0) and volatile phenols spiked (TF) red wines and wines treated with seven activated carbons, C1 to C7. The phenolic content of the wines was quantified using the absorbance at 280 nm before and after precipitation of the flavonoid phenols, through reaction with formaldehyde, according to [22]. The results were expressed as gallic acid equivalents by means of calibration curves with standard gallic acid. The total phenolic content was also determined by a spectrophotometric method, using a UV-vis spectrophotometer according to [23].   [17].  Table 7 Total phenols, flavonoid phenols, non-flavonoid phenols, total anthocyanins and chromatic properties of red wines spiked with volatile phenols (TF) and after treatment with activated carbons with different physicochemical characteristics (C1-C7).    Table 9 Monomeric anthocyanin composition (mg/L) of red wines spiked with volatile phenols (TF) and after treatment with activated carbons with different physicochemical characteristics (C1-C7).

High performance liquid chromatography (HPLC) analysis of anthocyanins and phenolic acids
Analyses were carried out with an Ultimate 3000 HPLC equipped with a PDA-100 photodiode array detector and an Ultimate 3000 pump according to [24]. Quantification was performed with calibration curves with standards caffeic acid, coumaric acid, ferulic acid, gallic acid and catechin. The results of trans-caftaric acid, 2-S-glutathionylcaftaric acid (GRP) and caffeic acid ethyl ester were expressed as caffeic acid equivalents by means of calibration curves with standard caffeic acid. On the other hand, coutaric acid, coutaric acid isomer and coumaric acid ethyl ester were expressed as coumaric acid equivalents by means of calibration curves with standard coumaric acid. A calibration curve of malvidin-3-glucoside, cyanidin-3-glucoside and peonidin-3-glucoside were used for quantification of anthocyanins. Using the coefficient of molar absorptivity (ε) and by extrapolation, it was possible to obtain the slopes for delphinidin-3-glucoside, petunidin-3-glucoside, and malvidin-3coumaroylglucoside and perform the quantification. The results of delphinidin-3-acetylglucoside, petunidin-3-acetylglucoside, peonidin-3-acetylglucoside, cyanidin-3-acetylglucoside and cyanidin-3coumaroylglucoside were expressed as respective glucoside equivalents.

Determination of 4-EP and 4-EG by liquid-liquid extraction and GC-MS analysis
The extractions were carried out following and adapting the methodology described by [25].
2.9. Headspace wine aroma composition by solid phase microextraction (HS-SPME) For the determination of the headspace aroma composition of red wines a validated method, confirmed in our laboratory was used [6].

Sensory evaluation
Sensory analysis was performed by a panel composed by six experts [26]. Fifteen attributes were selected: visual (limpidity, hue, colour intensity and oxidised), aroma (fruity, floral, vegetable character, phenolic and oxidised aroma) and taste and tactile/textural descriptors (taste-bitterness, acidity, tactile/textural-astringency, body, balance and persistence) using an adapted tasting sheet based on that recommended by the OIV [27]. The attributes were quantified using a five-point intensity scale [28]. Scales were anchored with the terms "low intensity" for score one and "high intensity" for score five, and panellists only scored integer values. All evaluations were conducted from 10:00 to 12:00 p.m. in an individual booth [29], using the recommended glassware according to [29]. A wine volume of 50 mL was used in order to be possible for the tasters to taste twice 25 mL of wine [30] and presented in random order [26].

Statistical treatment
Statistically significant differences between means were determined by analysis of variance (ANOVA) followed by Tukey honestly significant difference (HSD, 5% level) post-hoc test for the physicochemical data and a post-hoc Duncan test for sensory data. A principal component analyses was also performed to analyse the data and to study the relations between physicochemical ACs characteristics and wine volatile phenols removal and on phenolic and aromatic wine composition. These analyses were performed using Statistica 7 Software (StatSoft, Tulsa, OK U.S.A.). Generalised Procrustes Analysis [5] (GPA, XLSTAT-MX) of the sensory data was performed using XLSTAT (Addinsoft, Anglesey, UK). Multiple Factor Analysis (MFA, XLSTAT-RIB) of the sensory and chemical data were performed using XLSTAT (Addinsoft, Anglesey, UK).