1 3 Eur Food Res Technol (2016) 242:1913–1923 DOI 10.1007/s00217-016-2691-3 ORIGINAL PAPER Phenolic composition of BRS Violeta red wines produced from alternative winemaking techniques: relationship with antioxidant capacity and sensory descriptors Maurício Bonatto Machado de Castilhos1 · Iasnaia Maria de Carvalho Tavares2 · Sergio Gómez‑Alonso3,4 · Esteban García‑Romero5 · Vanildo Luiz Del Bianchi1 · Isidro Hermosín‑Gutiérrez3 Received: 15 January 2016 / Accepted: 9 April 2016 / Published online: 25 April 2016 © Springer-Verlag Berlin Heidelberg 2016 cap wine presented lower anthocyanin concentration due to the limited mechanical effect caused by the constant contact between pomace and must during maceration. The 3-glucoside of the myricetin was the principal fla- vonol, and large amounts of coumaric and caffeic acids were observed due to the high degree of hydrolysis of their precursors, named coutaric and caftaric acids. Both alternative winemaking procedures presented no differ- ences in the flavan-3-ol concentrations, and the antioxi- dant capacity of the wines did not significantly differ. The lack of differences in the main sensory descriptive attrib- utes showed that the alternative procedures have great potential to be applied as an alternative to the traditional treatment. Keywords Red wine · Winemaking · Antioxidant capacity · Polyphenols · Descriptive analysis Introduction In general, grape is considered one of the greatest sources of phenolic compounds when compared to other fruits and vegetables [1, 2]. American grapes and their hybrids (Vitis labrusca) show some disadvantages when compared with European grapes (Vitis vinifera) concerning their low solu- ble solids in their optimal stage of ripening and low color potential [3]. In order to minimize these effects, the Brazil- ian Agro-Farming Research Agency EMBRAPA Grape and Wine developed new cultivars such as BRS Violeta, which is a result from the cross between ‘BRS Rúbea’ and ‘IAC 1398-21’ [4]. BRS Violeta grape cultivar has become a blend agent to varietal red wines with poor color intensity, since it presents high color intensity, unique flavor and rich Abstract The detailed phenolic composition, sensory profile and antioxidant capacity of red wines produced from the BRS Violeta grape cultivar have been studied. The alternative winemaking procedures of grape pre-dry- ing and submerged cap have been assessed against the tra- ditional treatment. Malvidin was the principal anthocya- nidin of BRS Violeta wines, followed by delphinidin and petunidin. It was possible to detect 17 different types of pyranoanthocyanins derived from the five anthocyanidins in their non-acylated, acylated and coumaroylated forms, being vitisin A-types and hydroxyphenyl-pyranoanthocy- anins the main forms detected. Pre-dried wine presented low concentrations of anthocyanins, suggesting that they were partially degraded by the thermal treatment as a result of cleavage of covalent bounds and/or by degly- cosylation of the anthocyanin 3-glucosides. Submerged Electronic supplementary material The online version of this article (doi:10.1007/s00217-016-2691-3) contains supplementary material, which is available to authorized users. * Maurício Bonatto Machado de Castilhos mbonattosp@yahoo.com.br 1 Bioprocess Laboratory, Engineering and Food Technology Department, São Paulo State University, Cristóvão Colombo Street, São José do Rio Preto, São Paulo 2265, Brazil 2 Fruits and Vegetables Laboratory, São Paulo State University, São José do Rio Preto, São Paulo, Brazil 3 Instituto Regional de Investigación Científica Aplicada, Universidad de Castilla-La Mancha, Avda. Camilo José Cela S/N, 13071 Ciudad Real, Spain 4 Parque Científico y Tecnológico de Albacete, Passeo de la Innovación, 1, 02006 Albacete, Spain 5 Instituto de la Vid y el Vino de Castilla-La Mancha, Carretera de Albacete s/n, 13700 Tomelloso, Spain http://crossmark.crossref.org/dialog/?doi=10.1007/s00217-016-2691-3&domain=pdf http://dx.doi.org/10.1007/s00217-016-2691-3 1914 Eur Food Res Technol (2016) 242:1913–1923 1 3 antioxidant properties. Few reported studies concern- ing the BRS Violeta wine phenolic composition have revealed a high anthocyanin content ranging from 1866 to 2173 mg L−1 [5] and 1555.35 mg L−1 as malvidin 3,5-diglucoside equivalents [6]. The aforementioned stud- ies were focused only on the phenolic composition of Vio- leta grapes and wines and presented no data related to sen- sory features and, subsequently, their relationship with the phenolic composition. Furthermore, in comparison with the several studies worldwide, which contemplate red wines produced from Vitis vinifera grapes, there is a lack of studies dealing with the relationship between phenolic composition and sen- sory descriptive attributes [6–8]. Moreover, no studies were found dealing with BRS Violeta red table wines produced following variations in winemaking procedures in order to enhance the quality of these wines. Winemakers have employed several variations on win- emaking by the application of drying process of the grapes before fermentation [9] and the use of submerged cap dur- ing the alcoholic fermentation [10]. Studies dealing with grape pre-drying showed that the heating caused an irre- versible damage in the cellular structure of the grape skin increasing the extraction of the phenolic compounds to the wine during alcoholic fermentation [9]. In contrast, the thermal degradation of anthocyanins is a well-known phenomenon that could occur in par- allel to the pre-drying of grapes [11]. Submerged cap winemaking procedure allows for the constant contact between the pomace and the must, increasing the extrac- tion of anthocyanins and restricting the extraction of the flavan-3-ols from the seeds and skins to the must dur- ing alcoholic fermentation, due to the limitation of the mechanical effect caused by the pumped must on the grape pomace. All the above-mentioned studies pre- sented relevant results; however, they handled with Vitis vinifera red wines and presented no relationships with sensory data. In this context, the aim of this work was to evaluate the detailed phenolic composition, obtained by HPLC–DAD- ESI–MS/MS of BRS Violeta red wines produced from two alternative winemaking procedures, pre-drying and sub- merged cap wines, in comparison with the traditional win- emaking procedure. The study of the quantitative and quali- tative phenolic profiles covered the main grape and wine flavonoids (anthocyanins, flavonols and flavan-3-ols) and other interesting minor phenolic compounds (pyranoantho- cyanins, hydroxycinnamic acid derivatives and stilbenes). Additionally to the phenolic profiles, wine sensory descrip- tive attributes and antioxidant capacity were measured in order to evaluate the potential of the alternative winemak- ing procedures. Materials and methods Chemicals All solvents were of HPLC quality, all chemicals were of analytical grade (>99 %) and the water was of Milli-Q quality. The following commercial standards from Phyto- lab (Vestenbergsgreuth, Germany) were used for the iden- tification of the phenolic compounds: malvidin 3-gluco- side, malvidin 3,5-diglucoside, peonidin 3,5-diglucoside, trans-piceid, trans-caftaric acid, (−)-epigallocatechin and (−)-gallocatechin, as also the following commercial standards from Extrasynthese (Genay, France): cyanidin 3-glucoside, cyanidin 3,5-diglucoside, procyanidins B1 and B2, kaempferol, quercetin, isorhamnetin, myricetin, syringetin and the 3-glucosides of kaempferol, quercetin, isorhamnetin and syringetin. In addition, the following commercial standards from Sigma-Aldrich (Tres Cantos, Madrid, Spain) were used: trans-resveratrol, caffeic acid, (+)-catechin, (−)-epicatechin, (−)-epicatechin 3-gallate and (−)-gallocatechin 3-gallate. Other non-commercial flavonol standards such as myricetin 3-glucoside, querce- tin 3-glucuronide and laricitrin 3-glucoside were previ- ously isolated from Petit Verdot grape skins [12]. Procya- nidin B4 was kindly supplied by Prof. Fernando Zamora (Department of Biochemistry and Biotechnology, Univer- sitat Rovira i Virgili, Spain). The trans isomers of resvera- trol and its 3-glucosides (piceid) were converted into their respective cis isomers by UV irradiation (366 nm light for 5 min in quartz vials) of 25 % MeOH solutions of the trans isomers. All the standards were used for identification and quan- titation by calibration curves covering the expected con- centration ranges. When a standard was not available, the quantitation was done using the calibration curve of the most similar compound: malvidin 3,5-diglucoside for 3,5-diglucoside anthocyanin type and malvidin 3-glucoside for the 3-glucoside type, quercetin 3-glucoside for flavonol 3-glycosides and their free aglycones, caffeic acid for hydroxycinnamic acid derivatives, (+)-catechin for poly- meric flavan-3-ols (total proanthocyanidins), and individual flavan-3-ol monomers and dimers by their correspond- ing standards considering their total sum as (+)-catechin equivalents. Winemaking Three red wines were produced in duplicate: traditional Violeta wine (VIOT), pre-dried Violeta wine (VIOPD) and submerged cap Violeta wine (VIOSC) (2 × 7 kg × 3 treat- ments), totaling 42 kg of grapes were harvested in the city of Jales (20°16′ 7″ South and 50°32′58″ West), São Paulo 1915Eur Food Res Technol (2016) 242:1913–1923 1 3 state, Brazil, in 2013 vintage, at their expected maturity level and in good sanitary conditions, since they presented, at the start of the winemaking procedure, soluble sol- ids content of 18.5 ± 0.4 °Brix, pH value of 3.33 ± 0.02 and total acidity of 4.10 ± 0.18 g L−1 as tartaric acid equivalents. All the treatments followed the standard winemak- ing procedure previously described by De Castilhos et al. [13]. The mixture (must + pomace) was placed into 10-L fermentation vessels and treated with sulfur dioxide (86.2 ppm), and alcoholic fermentation was induced by the inoculation of 200 ppm of dry active Saccharomyces cer‑ evisiae yeasts Y904 (Amazon Group®). An aliquote of the must was removed for determination of the soluble solids in order to proceed with the chaptalization. The wines were macerated for 7 days with twice-daily punching-down, and after this time, the wines were dejuiced and chaptalized to 11 % v/v of ethanol by the direct insertion of sucrose (chaptalization). After dejuicing, the wines were properly racked three times at 10 day intervals, and between the first and second rackings, the malolactic fermentation took place by the inoculation of acid lactic bacteria Oenococ‑ cus oeni. The finalization of this second fermentation was followed by Thin Layer Chromatography [14]. Between the second and third rackings, the wines were placed in a refrigerated ambient (0–5 °C) for 10 days in order to stabi- lize the tartrate. The wines were then bottled and stabilized for 90 days. The submerged cap treatment provided the effect of the constant maceration of the grape’s solid parts by using stainless steel screens to maintain the cap at the bottom of the fermentative vessel, avoiding its rise due to the produc- tion of carbon dioxide. Submerged cap wines, as well as traditional wines, were chaptalized to 11 %v/v by the inser- tion of 33.5 g of sucrose per L of wine. Pre-drying treatment consisted of drying the grapes to 22 °Brix prior to alcoholic fermentation to avoid chaptali- zation and obtain wines with an alcoholic content between 8.6 and 14 % v/v, as required by Brazilian legislation [15]. This winemaking process was carried out using a convec- tive drying method with a tray dryer at 60 °C and airflow of 1.1 m s−1 [13]. At the end of drying procedure, Violeta wines presented 22.6 °Brix, with 12.7 % of the water evap- orated in relation to the initial weight. The following conventional enological parameters were measured: total and volatile acidities (as g L−1 tartaric and acetic acid equivalents, respectively) [15]; dry extract (g L−1) by gravimetric method [16]; reducing sugars (g L−1) by the Lane-Eynon method [16]; alcoholic content (ALC) (%v/v) by pycnometry [16]; and total phenolic con- tent by spectrophotometric procedure using gallic acid as standard [17]. Analysis of the phenolic compounds Preparation of the wine for the determination of the non‑anthocyanin phenolic compounds The flavonol fractions were isolated from diluted wine samples following the procedure described by Castillo- Muñoz et al. [18], using Bond Elute Plexa PCX solid-phase extraction cartridges (Agilent; 6 cm3, 500 mg of adsorbent). The flavan-3-ols (monomers, B-type dimers and polymeric proanthocyanidins) and stilbenes were isolated following the procedure described by Rebello et al. [19], using SPE C18 cartridges (Waters® Sep-Pak Plus, filled with 820 mg of adsorbent). HPLC–DAD–ESI–MSn analysis of the phenolic compounds The HPLC separation, identification and quantitation of the phenolic compounds were carried out on an Agilent 1100 Series HPLC system (Agilent, Germany) equipped with DAD (G1315B) and a LC/MSD Trap VL (G2445C VL) electrospray ionization mass spectrometry (ESI- MSn) system, coupled to an Agilent ChemStation (ver- sion B.01.03) data-processing unit. The mass spectra data were processed using the Agilent LC/MS Trap software (version 5.3). The anthocyanin, flavonols and hydroxycinnamic acid derivatives (HCAD) were analyzed according to a pre- viously described method [20]. The wine samples were injected (10 μL for anthocyanin analysis and 20 μL for fla- vonol analysis) onto a Zorbax Eclipse XDB-C18 reversed- phase column (2.1 × 150 mm; 3.5 µm particle; Agilent, Germany) with the temperature controlled at 40 °C. For identification, the ESI/MS–MS was used in both the positive (anthocyanins) and negative (flavonols and hydroxycinnamic acid derivatives) ionization modes set for the following parameters: dry N2 gas with a flow of 8 L min−1 at a drying temperature of 325 °C; and N2 nebulizer at 50 psi. The ionization and fragmentation parameters were optimized by direct injection of the appropriate standard solutions (malvidin 3,5-diglucoside solution in the positive ionization mode; quercetin 3-glu- coside and caftaric acid in the negative ionization mode) using a scan range of 50–1200 m/z. The anthocyanin and pyranoanthocyanin identification was based on the spec- troscopic data (UV–Vis and MS/MS) obtained from the aforementioned authentic standards or using previously reported data [5–7, 18–22]. For quantitation, the DAD- chromatograms were extracted at 520 nm for anthocya- nins, 360 nm for flavonols and 320 nm for the hydroxy- cinnamic acid derivatives (HCAD). The analyses were carried out in duplicate. 1916 Eur Food Res Technol (2016) 242:1913–1923 1 3 Identification and quantitation of the flavan‑3‑ols and stilbenes using multiple reaction monitoring (MRM) HPLC–ESI–MS/MS The analysis was carried out using a HPLC Agilent 1200 series system equipped with DAD (Agilent, Germany) and coupled to an AB Sciex 3200 TRAP (Applied Biosystems) with triple quadrupole, turbo spray ionization (electro- spray assisted by a thermonebulization) mass spectroscopy system (ESI–MS/MS). The chromatographic system was managed an Agilent ChemStation (version B.01.03) data- processing unit, and the mass spectra data were processed using the Analyst MSD software (Applied Biosystems, ver- sion 1.5). Structural information concerning the proanthocya- nidins was obtained using the pyrogallol-induced acid- catalyzed depolymerization method [23]. The reaction consisted of adding 0.50 mL of the pyrogallol solution (100 g L−1 pyrogallol plus 20 g L−1 of ascorbic acid in 0.3 N HCl) to 0.25 mL of the sample in MeOH and incubating 40 min at 30 °C. The hydrolysis reaction was stopped by adding 2.25 mL of sodium acetate (67 mM). An aliquot of 2 mL of the reacted sample was placed in a vial and injected directly into the equipment for analysis. The samples, before and after the acid-catalyzed depo- lymerization reaction, were injected (20 µL) onto an Ascen- tis C18 reversed-phase column (150 mm × 4.6 mm with 2.7 µm of particle size), with the temperature controlled at 16 °C. The solvents and gradients used for this analy- sis and the two MS scan types used (enhanced MS—EMS, and multiple reaction monitoring—MRM) as well as all the mass transitions (m/z) for identification and quantitation were according to the methodology reported by Lago-Van- zela et al. [20]. Determination of the antioxidant capacity by the DPPH assay The procedure consisted of adding 100 µL of wine diluted in methanol to 2.9 mL of a methanolic DPPH (2,2-diphe- nyl-1-picrylhydracyl, Fluka Chemie) radical solution (6 × 10−5 molL−1) [24]. After 25 min, the decrease in the percent absorbance at 515 nm was measured. For this measurement, the range should be between 20 and 80 % of the initial DPPH absorbance and thus the dilution of the wine with methanol was adjusted in order to enter this range; for red wines, the usual dilution factors are between 1/10 and 1/20. Quantitation of the antioxidant capac- ity was achieved using calibration curves obtained with methanolic solutions of Trolox (R2 = 0.9962) (6-hydroxy- 2,5,7,8-tetramethylchroman-2-carboxylic acid, Fluka, Chemie). Sensory analysis Ten panelists (Embrapa Grape and Wine, Brazil) with more than 15 years of wine tasting experience used descriptive analysis to profile the red table wines. They took part in a session using different wines among the produced samples (traditional, pre-dried and submerged cap) and reference standards. After a brief discussion among the panelists, a list of eleven attributes was established, two attributes for appearance (color intensity, violet hue) and nine for taste (sweetness, acidity, bitterness, flavor intensity/body, struc- ture/tannins, herbaceous taste, astringency, pungency and persistence). The evaluation sessions took place in a sen- sory analysis room with individual booths under daylight at ambient temperature. Aliquots of 30 mL of the red wines at 18 °C were poured into transparent glass cups, and for each wine, the panelists evaluated each descriptor on a horizontal unstructured 9-cm scale anchored by the mini- mum and maximum extremes. All the samples were coded with three random digits and were presented in a monadic and randomized form. The panelists evaluated the samples in triplicate [25]. The Ethical Issues regarding the sensory analysis were approved by the Ethics in Research Com- mittee of the Institute of Biosciences, Humanities and Exact Sciences, São Paulo State University (process no. 15159913.3.0000.5466). Data analysis All the data were treated using a one-way analysis of vari- ance (ANOVA) followed by Tukey’s post hoc test (when p < 0.05). All the statistical tests were applied at a signifi- cance level of 0.05 using the Minitab 17 software (Minitab Inc.). Results and discussion Conventional enological parameters The alternative winemaking techniques, pre-drying (PD) and submerged cap (SC), have influenced all the conven- tional enological parameters (p < 0.05), except the total phenolic content (PHEN) (p > 0.05), suggesting that these aforementioned alternative winemaking techniques did not significantly affect these compounds, as previously reported by De Castilhos et al. [3] (Supplementary Table). It was expected that VIOPD and VIOSC presented lower total phenolic concentration due to the phenolic degrada- tion caused by the heating and to the limited extraction promoted by the absence of pumping-over effects during maceration, respectively; however, the differences were not significant. 1917Eur Food Res Technol (2016) 242:1913–1923 1 3 Anthocyanin and pyranoanthocyanin profiles The 3,5-diglucosides of the five expected wine anthocya- nidins (delphinidin, cyanidin, petunidin, peonidin and mal- vidin) were identified and quantitated by DAD-chromato- grams at 520 nm, with the different forms of malvidin as the principal anthocyanidin, followed by delphinidin and petu- nidin (Table 1; Fig. 1a). The monoglucoside anthocyanins were not found in any Violeta red wines, and this could explain the formation of the hydroxyphenyl-pyranoantho- cyanins, which are resulted from the reaction between the monoglucoside anthocyanins and hydroxycinnamic acids, namely 10-(3″-hydroxyphenyl) (10-HP; reaction products with p-coumaric acid) or 10-(3″, 4″-dihydroxyphenyl) (10- DHP; reaction products with caffeic acid); and type-A and type-B vitisins, which are formed by the reaction between Table 1 Anthocyanins and pyranoanthocyanins profiles determined by HPLC/MS/MS (mean value ± standard deviation) for BRS Violeta young red wines Different letters in the same row indicate significant differences (ANOVA, Tukey’s post hoc test, α = 0.05) Dp delphinidin, Cy cyanidin, Pt petunidin, Pn peonidin, Mv malvidin, 3,5‑diglc 3,5-diglucosides, 3‑acglc‑5‑glc 3-(6′′-acetyl)-glucoside-5-gluco- side, 3‑cmglc‑5‑glc 3-(6′′-p-coumaroyl)-glucoside-5-glucoside, 3‑glc 3-glucoside, 3‑acglc 3-(6′′-acetyl)-glucoside, 3‑cmglc 3-(6′′-p-coumaroyl)- glucoside, 10‑HP 10-p-hydroxyphenyl, 10‑DHP 10-p-dihydroxyphenyl, VIOT Traditional Violeta wine, VIOPD Pre-drying Violeta wine, VIOSC submerged cap Violeta wine, ND not detectable, NQ not quantifiable Anthocyanidins and pyranoanthocyanins Peak Rt (min) Molecular ion; product ions (m/z) VIOT VIOPD VIOSC Anthocyanins (mg L−1) 818.24 ± 8.17 a 123.72 ± 13.06 c 335.69 ± 0.91 b Dp-3,5diglc 1 4.5 627; 465,303 164.30 ± 4.94 a 16.46 ± 2.88 c 46.41 ± 0.02 b Cy-3,5diglc 2 6.5 611; 449,287 56.37 ± 1.44 a 5.43 ± 0.65 c 27.43 ± 0.56 b Pt-3,5diglc 3 9.5 641; 479,317 130.84 ± 1.62 a 25.29 ± 4.62 c 60.73 ± 0.05 b Pn-3,5diglc 4 12.1 625; 463,301 72.83 ± 0.69 a 9.52 ± 2.28 c 34.97 ± 0.05 b Mv-3,5diglc 5 14.0 655; 493,331 194.18 ± 0.73 a 38.95 ± 2.07 c 103.23 ± 0.31 b Cy-3acglc-5glc 6 16.5 463; 301 3.59 ± 0.17 a 1.95 ± 0.25 b 2.63 ± 0.18 b Pt-3acglc-5glc 7 18.2 683; 521,479,317 7.50 ± 0.06 a 2.31 ± 0.23 c 4.25 ± 0.23 b Mv-3acglc-5glc 8 21.7 697; 535,493,331 1.50 ± 0.04 b 1.29 ± 0.02 b 2.10 ± 0.10 a Dp-3cmglc-5glc 10 23.9 773; 611,465,303 76.22 ± 1.58 a 4.47 ± 0.27 c 12.04 ± 0.09 b Cy-3cmglc-5glc 11 25.8 757; 595,449,287 20.33 ± 0.57 a 1.87 ± 0.00 c 7.26 ± 0.21 b Pt-3cmglc-5glc 12 27.4 801; 639,493,331 44.56 ± 0.14 a 5.70 ± 0.12 c 13.70 ± 0.15 b Pn-3cmglc-5glc 15 29.8 771; 609,463,301 8.92 ± 0.12 a 1.98 ± 0.23 c 3.50 ± 0.03 b Mv-3cmglc-5glc 16 30.5 801; 639,493,331 33.56 ± 0.38 a 6.84 ± 0.25 c 15.15 ± 0.03 b Pyranoanthocyanins (mg L−1) 46.75 ± 0.49 a 40.75 ± 1.48 b 40.60 ± 1.13 b 10-Carboxy-pyrpt-3cmglc 9 23.3 503; 341 NQ NQ NQ 10-Carboxy-pymv-3cmglc (cm-vitisin A) 13 28.1 707; 399 5.51 ± 0.01 NQ 4.52 ± 0.11 10HP-pyrdp-3glc 14 28.9 581; 419 6.26 ± 0.31 a 5.98 ± 0.17 a 5.73 ± 0.00 a 10DHP-pyrpt-3glc 17 31.9 611; 449 NQ NQ NQ 10HP-pyrcy-3glc 18 32.8 565; 403 4.27 ± 0.01 a 4.02 ± 0.05 a 4.40 ± 0.18 a 10HP-pyrpt-3glc 19 34.6 595; 433 8.14 ± 0.22 a 8.05 ± 0.00 a 6.45 ± 0.09 b 10HP-pyrdp-3cmglc 20 34.8 727; 419 NQ NQ NQ 10DHP-pyrpt-3cmglc 21 36.2 757; 449 2.26 ± 0.35 a 2.24 ± 0.05 a 2.06 ± 0.09 a 10DPH-pyrmv-3glc 22 36.7 625; 463 4.17 ± 0.95 a 3.80 ± 0.17 a 3.00 ± 0.87 a 10HP-pyrpt-3acglc 23 37.2 637; 433 NQ NQ NQ 10HP-pyrpn-3glc 24 38.2 579; 417 5.04 ± 0.00 a 4.68 ± 0.51 a 4.53 ± 0.18 a 10HP-pyrcy-3cmglc 25 38.6 711; 403 NQ NQ NQ 10HP-pyrmv-3glc 26 39.6 609; 447 4.61 ± 0.21 a 4.85 ± 0.36 a 4.24 ± 0.01 a 10HP-pyrpt-3cmglc 27 40.3 741; 433 4.71 ± 0.38 a 5.16 ± 0.27 a 4.55 ± 0.00 a 10DHP-pyrmv-3cmglc 28 41.6 771; 463 0.69 ± 0.15 a 0.62 ± 0.00 a 0.31 ± 0.07 a 10HP-pyrpn-3cmglc 29 42.1 725; 417 0.32 ± 0.00 a 0.32 ± 0.00 a 0.20 ± 0.02 b 10HP-pyrmv-3cmglc 30 42.3 755; 447 0.76 ± 0.03 ab 0.97 ± 0.00 a 0.56 ± 0.11 b 1918 Eur Food Res Technol (2016) 242:1913–1923 1 3 monoglucoside anthocyanins and yeast metabolites such as pyruvic acid and acetaldehyde, respectively [21]. It was possible to detect 17 different pyranoanthocya- nins derived from the five known anthocyanidins by means of their MS, MS/MS and UV–Vis spectral data, most of them being 10 (4′′′-hydroxyphenyl) (10-HP) and 10-(3′′′, 4′′′-dihydroxyphenyl) (10-DPH) derivatives of the five possible pyranoanthocyanidins in their different forms of non- acylated, acylated and p-coumaroylated glucosides [21]. The p-coumaroyl derivative of vitisin A (10-carboxy-pyranomal- vidin-3-p-coumaroylglucoside) and the similar A-type vitisin derived from petunidin were detected in all samples; how- ever, only the p-coumaroylated vitisin A was possible to be quantitated in traditional and submerged cap wines. Fig. 1 HPLC DAD-chroma- togram (detection at 520 nm) of BRS Violeta young red wines anthocyanins a for peak assignation, see Table 1; HPLC DAD-chromatogram (detection at 360 nm) of flavonols (b) and HPLC DAD-chromatogram (detection at 320 nm) of hydroxycinnamic acid deriva- tives (HCAD) c for b and c peak assignation, see Table 2 1919Eur Food Res Technol (2016) 242:1913–1923 1 3 The 3-(6′′-coumaroyl)-glucoside-5-glucoside (3cmglc- 5glc) derivatives of the five anthocyanidins were also detected. Traditional wine showed high concentration for all coumaroylated anthocyanins (3cmglc-5glc) followed by VIOSC and VIOPD wines. The coumaroylated deriva- tive of delphinidin (dp-3cmglc-5glc) presented the higher concentration. The 3-(6′′-acetyl)-glucoside-5-glucoside (3acglc-5glc) derivatives of all anthocyanidins, except del- phinidin and peonidin, were found as minor compounds and were also quantitated. These results were in accordance with the findings of Lago-Vanzela et al. [5] who reported the higher concentration of mv-3,5diglc and dp-3-cmglc- 5-glc for young Violeta red wines from different vintages. Lago-Vanzela et al. [5] also reported the detection of the 3-(6′′-acetyl)-glucoside-5-glucoside forms of delphinidin and peonidin, and these compounds were not detected in BRS Violeta wines. In all anthocyanins quantitated, when statistical differ- ences were observed (p < 0.05, Table 1), the traditional wine presented higher amounts of these compounds when compared with VIOSC and VIOPD wines. A possible explanation for the lower concentration of these compounds in VIOPD wine is related to their degradation caused by the heat very likely due to the thermal degradation of these compounds caused by cleavage of the covalent bonds and/ or by deglycosylation of the anthocyanin 3-glucosides [9]. In contrast, the VIOPD wines also showed significantly higher pyranoanthocyanin contents, especially the so- called hydroxyphenyl-pyranoanthocyanins, the 10-HP- and 10-DHP-pyranoanthocyanins. The results seem to suggest that the formation of hydroxyphenyl-pyranoanthocyanins already occurred during the first steps of the pre-drying treatment, before the thermal degradation of the correspond- ing anthocyanin precursors. The increase of the tempera- ture could accelerate the hydrolysis of caftaric and coutaric acids, thus releasing the free caffeic and p-coumaric acids, respectively, that further reacted with anthocyanins [26]. The heating could modify the membrane permeability of the grape cells, thus allowing for the contact between anthocya- nins and released free caffeic and p-coumaric acids. In parallel, the heating could have effectively degraded tannins, which have been recognized as strong competi- tors of free caffeic and p-coumaric acid with regard to their reaction with anthocyanins [21, 27], since the tannins caused no interference in the reaction between hydroxy- cinnamic acids and anthocyanins. The afore-formulated hypothesis needs the final consideration that hydroxyphe- nyl-pyranoanthocyanins, once they were formed during the pre-drying treatment, might be more stable than anthocya- nidin 3-glucosides with regard to thermal degradation. As far as we know, we have not found any study dealing with thermal stability of pyranoanthocyanins. Furthermore, it was possible to suggest that pyranoanthocyanins showed more chemical stability [21] than anthocyanins, since the heating treatments of grape pre-drying weakly affected them. In addition, it was expected that VIOSC presented higher anthocyanin concentration when compared to VIOT wine due to the constant contact between the pomace (skins and seeds) and the must, which led to a better dissolution of the phenolic compounds such as tannins and anthocya- nins, both represented by the seeds and skins, respectively [28]; however, this aforementioned result was not possible to be observed, since VIOSC presented significantly lower concentration of these compounds when compared with VIOT. In this context, a possible explanation for this result was that the punching-down performed during maceration was responsible for the enhancement of the anthocyanin concentration in VIOT wine when compared with VIOSC wine [13]. Profile of the flavonols and hydroxycinnamic acid derivatives (HCAD) The 3-glucosides (3-glc) of the five aglycones (Q, quercetin; M, myricetin; L, laricitrin; S, syringetin and I, isorhamne- tin) were detected and quantitated in Violeta wines (Table 2; Fig. 1b). In addition, no 3-glucuronides (3-glcU) derivatives were detected and the free forms of four aglycones were detected and quantitated (M, Q, L and S). The 3-glucoside of M presented the highest concentrations in Violeta red wines, followed by the 3-glucosides of L, I and S, as well as free Q. This result was in accordance with findings of Lago- Vanzela et al. [5] who reported high concentration of myri- cetin 3-glucoside (M-3-glc) in Violeta red wines, however in disagreement with the findings of the same authors who reported no relevant concentrations for L-3-glc and free Q. Traditional wine showed higher concentration for free quercetin and VIOPD did not significantly differ from the VIOSC wine. In general, for all flavonols, except free Q, the lack of significant differences between the winemaking pro- cedures suggested the weak influence of the drying process on the concentration of these compounds. With regard to the hydroxycinnamic acid derivatives (HCAD), larger amounts of free p-coumaric and caffeic acids were observed (Table 2; Fig. 1c), thus indicating a high degree of hydrolysis of their grape native precursors, namely coutaric and caftaric acids, respectively, which accounted for minor concentrations. The high concentra- tions of free caffeic and p-coumaric acids in Violeta wines also explained the relevant concentrations found for their respective ethyl esters. The data concerning the HCAD showed that in almost all the comparisons, when the dif- ferences were significant (p < 0.05), the HCAD concen- trations in VIOPD wines were higher than the traditional (VIOT) and the VIOSC wines. 1920 Eur Food Res Technol (2016) 242:1913–1923 1 3 This result corroborates with the findings of Marquez et al. [9] who reported that the HCAD amounts of Tempra- nillo and Merlot red wines submitted to chamber-drying process at 40 °C presented significant differences when the initial and the final processes of drying were compared, and in almost all HCAD the concentration was higher after the drying. These authors also stated that the drying process allowed for the concentration of the HCAD by the water evaporation of the grapes before the winemaking procedure and this is a possible explanation for the increase of these compounds in pre-dried Violeta wines. The concentration of the caftaric, cis-coutaric, p-coumaric acids and ethyl esters presented no significant differences when the win- emaking procedures were compared (p > 0.05). In almost all cases, when p < 0.05, the submerged cap wine presented the same behavior as seen for the traditional treatment. Profile of the flavan‑3‑ols and stilbenes Catechin (C), epicatechin (EC), epicatechin 3-gallate (ECG), proanthocyanidin B1 (PB1) and proanthocyani- din B2 (PB2) were detected and quantitated in Violeta red wines, except PB4 which could not be quantitated for all treatments and VIOPD wine in which ECG was not found (Table 3). The lack of ECG in VIOPD wine could be caused by its accelerated hydrolysis under heating conditions of the pre-drying treatment, similarly to that hypothesized for the above-mentioned discussion of the results dealing with the higher content of hydroxyphenyl-pyranoanthocyanins in VIOPD wine. There were no significant differences on the flavan-3-ol contents when the winemaking procedures were compared, and this result suggests that both alterna- tive winemaking procedures did not influence the amounts of these aforementioned compounds. A possible explanation for this aforementioned result is due to a balance between flavan-3-ol losses and gains. On the one hand, the grapes lost their physiological integrity during dehydration, thus favoring the diffusion of phe- nolic compounds and flavan-3-ols, from the grape skin to the pulp, which could be transferred to wine during alco- holic fermentation, increasing their concentration [27]. On the other hand, the higher expected content of flavan- 3-ols in VIOPD wine due to the latter reason seems to be counteracted by the also expected thermal degradation Table 2 Flavonol and HCAD profile determined by HPLC/MS/MS (mean value ± standard deviation) for BRS Violeta young red wines Different letters in the same row indicate significant differences (ANOVA, Tukey’s post hoc test and Games Howell post hoc test1 when the variances were different, α = 0,05) M myricetin, Q quercetin, L laricitrin, K kaempferol, S syringetin, I isorhamnetin, glcU glucuronide, gal galactoside, glc glucoside, VIOT tradi- tional violeta wine, VIOPD pre-drying violeta wine, VIOSC submerged cap violeta wine Flavonols and HCAD Peak Rt (min) Molecular ion; product ions (m/z) VIOT VIOPD VIOSC Flavonols (mg L−1) 170.48 ± 30.60 a 100.74 ± 4.22 a 108.12 ± 26.10 a M-3-glc 31 21.5 479; 317 110.60 ± 19.60 a 72.19 ± 4.84 a 73.30 ± 15.20 a Q-3-glc 32 29.9 463; 301 5.86 ± 0.37 a 5.15 ± 1.48 a 2.33 ± 0.14 a L-3-glc 33 33.0 493; 331 17.40 ± 15.20 a 4.27 ± 1.32 a 11.77 ± 9.80 a Free M1 34 33.2 317 4.68 ± 3.54 a 2.53 ± 0.83 a 3.64 ± 0.17 a I-3-glc 35 40.1 477; 315 8.99 ± 5.29 a 4.50 ± 2.86 a 5.85 ± 1.38 a S-3-glc 36 41.6 507; 345 8.51 ± 2.68 a 4.96 ± 2.70 a 2.77 ± 0.59 a Free Q 37 45.0 301 10.72 ± 0.41 a 4.34 ± 1.41 b 4.73 ± 1.78 b Free L 38 48.7 331 2.78 ± 0.39 a 2.11 ± 0.74 a 2.41 ± 0.72 a Free S 39 57.6 345 0.86 ± 0.45 a 0.67 ± 0.64 a 1.33 ± 0.82 a Hydroxycinnamic acid derivatives (HCAD) (mg.L−1) 400.67 ± 25.60 a 502.03 ± 58.10 a 374.13 ± 16.50 a Caftaric acid 40 4.1 311; 179,149,135 1.29 ± 1.11 a 0.92 ± 0.08 a 1.11 ± 0.38 a Trans-coutaric acid1 41 6.1 295; 163,149,119 9.89 ± 0.03 ab 12.49 ± 0.32 a 7.98 ± 0.52 b Cis-coutaric acid 42 6.5 295; 163,149,119 4.33 ± 1.21 a 2.47 ± 0.51 a 3.01 ± 0.35 a Caffeic acid 43 7.8 179; 135 78.81 ± 3.71 a 69.82 ± 2.61 ab 53.43 ± 6.04 b p-Coumaroyl-glucose-1 44 9.0 325; 163,145 44.82 ± 3.23 b 66.32 ± 2.25 a 51.37 ± 4.73 b p-Coumaroyl-glucose-2 45 11.6 325; 163,145 21.76 ± 0.46 ab 27.49 ± 1.54 a 17.21 ± 1.87 b p-Coumaric acid 46 14.4 163; 119 196.50 ± 11.60 a 294.40 ± 59.70 a 184.35 ± 12.74 a Ethyl caffeate1 47 46.1 207; 179,135 3.78 ± 0.96 a 3.48 ± 1.14 a 1.11 ± 0.01 a Ethyl p-coumarate 48 55.8 191; 163,119 39.48 ± 12.97 a 24.63 ± 1.55 a 54.50 ± 17.70 a 1921Eur Food Res Technol (2016) 242:1913–1923 1 3 of these flavonoids, decreasing their concentration. The apparent balance between these two opposite effects could explain the lack of significant differences in the content of flavan-3-ols in VIOPD wines compared to the other wines. In addition, according to Ribéreau-Gayon et al. [29], the flavan-3-ols configuration affects their reactiv- ity, and this fact could be related to their high stability to heat, being an additional explanation for this result. The level of proanthocyanidins found in all Violeta wines were lower than those usually found in wines elaborated from Vitis vinifera grape cultivars, they were in agreement with the low content of proanthocyanidins reported for Violeta grapes [19]. With respect to stilbenes, cis-resveratrol, trans-piceid and cis-piceid were detected and quantitated for all wines. In all wines, the total and individual contents of each stil- bene were low and confirmed previous findings, suggesting that Violeta grape is a low resveratrol producer [19]. The content of resveratrol, its glycoside forms (piceids) and the global content of phenolic compounds have been suggested to be significantly correlated with the antioxidant capac- ity of grapes [7]. However, wines presenting high global amounts of stilbenes or phenolic concentration not always show the greatest antioxidant capacity, because this prop- erty depends more of the types of the phenolic compounds than their global amounts [7, 30, 31]. The values found for the antioxidant capacity (AC) of BRS Violeta wines according to the winemaking proce- dures did not significantly differ. The pre-drying process of the Violeta grapes was carried out using 60 °C and prob- ably induced Maillard reaction (non-enzymatic browning) that could take importance on the formation of compounds such as melanoidins with suggested antioxidant capacity, as reported by Tagliazucchi et al. [31] and Marquez et al. [9], and this could be a possible explanation for the absence of AC significant differences between VIOPD and VIOT/ VIOSC. Sensory assessment The comparison of the winemaking treatments only pro- vided significant differences with respect to the vio- let hue of the red wine color and its sweetness (Table 4). Pre-dried wine (VIOPD) showed intermediate values for both descriptive sensory attributes, the traditional wine (VIOT) high scores for sweetness and submerged cap wine (VIOSC) high scores for violet hue. The other sensory descriptors presented similar scores for all the three win- emaking procedures. The lack of significant differences in the main descriptive sensory attributes showed that the pre-drying and submerged cap winemaking procedures pre- sented potential to be applied as an alternative to traditional Table 3 Flavan-3-ol/stilbenes profiles determined by HPLC–ESI–MS/MS (MRM) and antioxidant capacity (mean value ± standard deviation) for BRS Violeta young red wines Different letters in the same row indicate significant differences (ANOVA, Tukey’s post hoc test and Games Howell post hoc test1 when the variances were different, α = 0,05) C catechin, EC epicatechin, ECG epicatechin gallate, PB1 proanthocyanidin B1, PB2 proanthocyanidin B2, PB4 proanthocyanidin B4, mDP mean degree of polymerization, VIOT traditional violeta wine, VIOPD pre-drying violeta wine, VIOSC submerged cap violeta wine, NQ not quantifiable Flavan-3-ols and stilbenes VIOT VIOPD VIOSC Flavan-3-ol monomers and dimers (mg L−1) 42.44 ± 30.20 a 29.54 ± 13.54 a 6.98 ± 2.32 a C 13.98 ± 7.58 a 12.40 ± 4.59 a 3.38 ± 1.16 a EC 2.02 ± 0.77 a 2.02 ± 0.51 a 0.56 ± 0.08 a ECG 0.03 ± 0.05 NQ 0.16 ± 0.23 PB11 19.70 ± 16.30 a 10.17 ± 5.71 a 2.16 ± 0.75 a PB21 6.75 ± 5.59 a 4.78 ± 2.50 a 0.87 ± 0.31 a PB4 NQ NQ NQ Proanthocyanidin total content (mg L−1) 91.26 ± 4.22 a 68.40 ± 16.80 ab 25.45 ± 6.94 b mDP 2.51 ± 0.11 a 1.99 ± 0.13 ab 1.63 ± 0.19 b % Galloylation 5.90 ± 0.64 ab 7.97 ± 0.19 a 2.66 ± 1.17 b % Prodelphinidin 7.53 ± 0.93 a 4.90 ± 0.49 a 4.57 ± 3.19 a Stilbenes (mg L−1) 0.97 ± 0.70 a 0.66 ± 0.18 a 0.20 ± 0.01 a cis-resveratrol 0.24 ± 0.20 a 0.08 ± 0.06 a 0.13 ± 0.02 a Cis-piceid 0.47 ± 0.66 a 0.43 ± 0.11 a 0.006 ± 0.00 a Trans-piceid 0.26 ± 0.24 a 0.14 ± 0.01 a 0.05 ± 0.01 a Antioxidant capacity (mmol L−1 of Trolox equivalents) 21.96 ± 1.33 a 18.51 ± 1.90 a 15.65 ± 1.81 a 1922 Eur Food Res Technol (2016) 242:1913–1923 1 3 winemaking, since the scores obtained for most descriptive attributes were similar. In addition, the high violet hue for VIOSC is a strong feature that can be considered as a sen- sory driver for acceptance of these red wines as reported by De Castilhos et al. [3]. Conclusion The chemical and sensory profiles provided essential infor- mation about the Violeta red wines submitted to alternative winemaking procedures. Pre-drying winemaking led to sig- nificantly different wines regarding the anthocyanin content when compared to traditional and submerged cap wines. Despite the inherent thermal degradation of the phenolic compounds during the pre-drying treatment, the heating may also have induced the formation of products by Mail- lard reactions, giving rise to the restitution of part of the lost antioxidant capacity and making the wines not significantly different according to the winemaking procedures. The uni- variate results showed the lack of significant differences in the descriptive sensory profile for the main attributes, show- ing that the submerged cap and pre-drying winemaking pro- cedures could be applied as an alternative to the traditional winemaking. In fact, the submerged cap red wines presented higher scored for violet hue and this sensory feature could be considered as a sensory acceptance driver. Finally, this study provided relevant results regarding the potential of the alternative winemaking procedures and their application in order to improve the Brazilian wine quality. Acknowledgments The author De Castilhos, M.B.M. thanks the Coor- dination for the Improvement of Higher Level Personnel (CAPES—Bra- zil) for the scholarship in the Overseas Doctoral Sandwich Program (PDSE). The authors are also grateful to the Brazilian Agro-farming Research Agency EMBRAPA Grape and Wine (Empresa Brasileira de Pesquisa Agropecuária, EMBRAPA Uva e Vinho) and all the wine experts who helped us in the sensory analysis. Author Gómez-Alonso, S. thanks the Fondo Social Europeo and the Junta de Comunidades de Castilla-La Mancha for co-funding his contract via the INCRECYT pro- gram. Also, the authors Gómez-Alonso, S. and Hermosín-Gutiérrez, I. are grateful to the Spanish Ministerio de Economía y Competitividad for financial support (project AGL2011-29708-C02-02). Compliance with ethical standards Conflict of interest The authors declare that they have no conflict of interest. Compliance with ethics requirements The ethics were provided for sensory evaluation by the process number linked with the Ethic Politics of the São Paulo State University. References 1. Biasoto ACT, Netto FM, Marques EJN, da Silva MAAP (2014) Acceptability and preference drivers of red wines produced from Vitis labrusca and hybrid grapes. Food Res Int 62:456–466 2. Granato D, Koot A, Schnitzler E, van Ruth SM (2015) Authenti- cation of geographical origin and crop system of grape juices by phenolic compounds and antioxidant activity using chemomet- rics. J Food Sci 80:584–593 3. De Castilhos MBM, Maia JDG, Gómez-Alonso S, Del Bianchi V, Hermosín-Gutiérrez I (2016) Sensory acceptance drivers of pre-fermentation dehydration and submerged cap red wines pro- duced from Vitis labrusca hybrid grapes. Lebensm Wiss Technol 69:82–90 4. Camargo UA, Maia JDG, Nachtigal JC (2005) BRS Violeta: nova cultivar de uva para suco e vinho de mesa. Embrapa Uva e Vinho, Bento Gonçalves 5. Lago-Vanzela ES, Rebello LPG, Ramos AM, Stringheta PC, Da- Silva R, García-Romero E, Gómez-Alonso S, Hermosín-Gutiér- rez I (2013) Chromatic characteristics and color-related phenolic composition of Brazilian young red wines made from the hybrid grape cultivar BRS Violeta (“BRS Rúbea” × “IAC 1398-21”). Food Res Int 54:33–43 6. Lago-Vanzela ES, Procópio DP, Fontes EAF, Ramos AM, String- heta PC, Da-Silva R, Castillo-Muñoz N, Hermosín-Gutiérrez I (2014) Aging of red wines made from hybrid grape cv. BRS Vio- leta: effects of accelerated aging conditions on phenolic compo- sition, color and antioxidant capacity. Food Res Int 56:182–189 7. Nixdorf SL, Hermosín-Gutiérrez I (2010) Brazilian red wines made from the hybrid grape cultivar Isabel: phenolic composi- tion and antioxidant capacity. Anal Chim Acta 659:208–215 8. De Castilhos MBM, Conti-Silva AC, Del Bianchi VL (2012) Effect of grape pre-drying and static pomace contact on physico- chemical properties and sensory acceptance of Brazilian (Bordô and Isabel) red wines. Eur Food Res Technol 235:345–354 9. Marquez A, Serratosa MP, Lopez-Toledano A, Merida J (2012) Colour and phenolic compounds in sweet red wines from Merlot and Tempranillo grapes chamber-dried under controlled condi- tions. Food Chem 130:111–120 10. Bosso A, Panero L, Petrozziello M, Follis R, Motta S, Guaita M (2011) Influence of submerged-cap vinification on polyphenolic composition and volatile compounds of Barbera wines. Am J Enol Viticult 62:503–511 Table 4 Descriptive sensory profile (mean ± standard deviation) for BRS Violeta red wines Different letters in the same row indicate significant differences (ANOVA, Tukey’s post hoc test, α = 0.05) VIOT traditional violeta wine, VIOPD pre-drying violeta wine, VIOSC submerged cap violeta wine Sensory attributes VIOT VIOPD VIOSC Appearance Color intensity 8.40 ± 0.59 a 8.41 ± 0.60 a 8.05 ± 0.75 a Violet hue 5.26 ± 2.85 b 6.33 ± 2.15 ab 6.76 ± 1.73 a Taste Sweetness 4.63 ± 1.57 a 3.78 ± 1.84 ab 3.30 ± 1.54 b Acidity 3.70 ± 1.12 a 3.86 ± 1.63 a 4.13 ± 1.39 a Bitterness 2.51 ± 1.98 a 3.30 ± 2.50 a 2.95 ± 2.04 a Flavor intensity/body 5.70 ± 1.47 a 6.00 ± 1.21 a 5.78 ± 1.05 a Structure/tannins 5.56 ± 1.90 a 5.90 ± 1.44 a 5.26 ± 1.57 a Herbaceous taste 2.58 ± 1.56 a 3.35 ± 1.62 a 3.43 ± 1.85 a Astringency 3.06 ± 1.84 a 2.95 ± 1.57 a 2.85 ± 1.45 a Pungency 5.86 ± 1.58 a 5.95 ± 1.16 a 5.73 ± 1.25 a Persistence 5.90 ± 1.32 a 5.86 ± 1.19 a 5.81 ± 1.12 a 1923Eur Food Res Technol (2016) 242:1913–1923 1 3 11. Patras A, Brunton NP, O’Donnell C, Tiwari BK (2010) Effect of thermal processing on anthocyanin stability in foods; mechanisms and kinetics of degradation. Trends Food Sci Technol 21:3–11 12. Castillo-Muñoz N, Gómez-Alonso S, García-Romero E, Gómez MV, Velders AH, Hermosín-Gutiérrez I (2009) Flavonol 3-O-glycosides series of Vitis vinifera cv. Petit Verdot red wine grapes. J Agr Food Chem 57:209–219 13. De Castilhos MBM, Cattelan MG, Conti-Silva AC, Del Bianchi VL (2013) Influence of two different vinification procedures on the physicochemical and sensory properties of Brazilian non- Vitis vinifera red wines. Lebensm Wiss Technol 54:360–366 14. Ribéreau-Gayon J, Peynaud E, Ribéreau-Gayon P, Sudraud P (1982) Traité d’oenologie: sciences et techniques du vin. Dunod, Paris 15. Brasil (2005) Altera dispositivos da Lei n. 7678 de 8 de novem- bro de 1988. Diário Oficial da União, Brasília 16. Association of Official Analytical Chemists (2005) Official methods of analysis of the AOAC international, 18th edn. Gaith- ersburg, Washington (Chapter 28) 17. Slinkard K, Singleton VL (1977) Total phenol analysis: auto- mation and comparison with manual methods. Am J Enol Vitic 28:49–55 18. Castillo-Muñoz N, Gómez-Alonso S, García-Romero E, Her- mosín-Gutiérrez I (2007) Flavonol profiles of Vitis vinifera red grapes and their single-cultivar wines. J Agr Food Chem 55:992–1002 19. Rebello LPG, Lago-Vanzela ES, Barcia MT, Ramos AM, String- heta PC, Da-Silva R, Castillo-Muñoz N, Gómez-Alonso S, Her- mosín-Gutiérrez I (2013) Phenolic composition of the berry parts of hybrid grape cultivar BRS Violeta (BRS Rubea × IAC 1398- 21) using HPLC-DAD-ESI–MS/MS. Food Res Int 54:354–366 20. Lago-Vanzela ES, Da-Silva R, Gomes E, García-Romero E, Hermosín-Gutiérrez I (2011) Phenolic composition of the edi- ble parts (flesh and skin) of Bordô grape (Vitis labrusca) using HPLC–DAD–ESI–MS/MS. J Agr Food Chem 59:13136–13146 21. Blanco-Vega D, López-Bellido FJ, Alía-Robledo JM, Hermosín- Gutiérrez I (2011) HPLC-DAD-ESI-MS/MS characterization of pyranoanthocyanins pigments formed in model wine. J Agr Food Chem 59:9523–9531 22. Barcia MT, Pertuzatti PB, Gómez-Alonso S, Godoy HT, Hermo- sín-Gutiérrez I (2014) Phenolic composition of grape winemak- ing by-products of Brazilian hybrid cultivars BRS Violeta and BRS Lorena. Food Chem 159:95–105 23. Bordiga M, Coïsson JD, Locatelli M, Arlorio M, Travaglia F (2013) Pyrogallol: an alternative trapping agent in proanthocya- nidins analysis. Food Anal Method 6:148–156 24. Brand-Williams W, Cuvelier ME, Berset C (1995) Use of a free radical method to evaluate antioxidant activity. Lebensm Wiss Technol 28:25–30 25. Girard B, Yuksel D, Cliff MA, Delaquis P, Reynolds AG (2001) Vinification effects on the sensory, colour, and GC pro- files of Pinot noir wines from British Colombia. Food Res Int 34:483–499 26. Rentzsch M, Schwarz M, Winterhalter P, Blanco-Vega D, Her- mosín-Gutiérrez I (2010) Survey on the content of vitisin A and hydroxyphenyl-pyranoanthocyanins in Tempranillo wines. Food Chem 119:1426–1434 27. Figueiredo-González M, Cancho-Grande B, Simal-Gándara J (2013) Effects on colour and phenolic composition of sugar con- centration processes in dried-on- and dried-off-vine grapes and their aged or not natural sweet wines. Trends Food Sci Technol 31:36–54 28. Suriano S, Ceci G, Tamborra T (2012) Impact of different wine- making techniques on polyphenolic compounds of Nero Di Troia wine. It Food Bev Technol 70:5–15 29. Ribéreau-Gayon P, Glories Y, Maujean A, Dubourdieu D (2006) Handbook of enology. In: Ribéreau-Gayon P, Glories Y, Maujean A, Dubourdieu D (eds) The Chemistry of wine: Stabilization and Treatments. Wiley, Chichester 30. Rivero-Pérez MD, Muñiz P, González-San José ML (2007) Anti- oxidant profile of red wines evaluated by total antioxidant capac- ity, scavenger capacity, and biomarkers of oxidative stress meth- odologies. J Agr Food Chem 55:5476–5483 31. Tagliazucchi D, Verzelloni E, Conte A (2008) Antioxidant prop- erties of traditional balsamic vinegar and boiled must model sys- tems. Eur Food Res Technol 227:835–843 Phenolic composition of BRS Violeta red wines produced from alternative winemaking techniques: relationship with antioxidant capacity and sensory descriptors Abstract Introduction Materials and methods Chemicals Winemaking Analysis of the phenolic compounds Preparation of the wine for the determination of the non-anthocyanin phenolic compounds HPLC–DAD–ESI–MSn analysis of the phenolic compounds Identification and quantitation of the flavan-3-ols and stilbenes using multiple reaction monitoring (MRM) HPLC–ESI–MSMS Determination of the antioxidant capacity by the DPPH assay Sensory analysis Data analysis Results and discussion Conventional enological parameters Anthocyanin and pyranoanthocyanin profiles Profile of the flavonols and hydroxycinnamic acid derivatives (HCAD) Profile of the flavan-3-ols and stilbenes Sensory assessment Conclusion Acknowledgments References