Compuestos azufrados volÃ¡tiles en vinos - FundaciÃ³n para la ...

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Effect of Micro-oxygenation on Color and Anthocyanin-Related Compounds of Wines with Different Phenolic ContentsTable 1. Evolution of Some PhysicochemicalParameters during MO of Monastrell Wines apHtitratable acidity bvolatile acidity cfree SO 2(mg/L)total SO 2(mg/L)acetaldehyde (mg/L)pHtitratable acidity bvolatile acidity cfree SO 2(mg/L)total SO 2(mg/L)acetaldehyde (mg/L)pHtitratable acidity bvolatile acidity cfree SO 2(mg/L)total SO 2(mg/L)acetaldehyde (mg/L)t 0t 1t 2t 3W13.725.870.39253922.2W23.666.310.33254129.1W33.636.450.40274832.3W1(C)3.785.760.40263213.5W2(C)3.715.830.33313523.0W3(C)3.665.700.37324425.6W1(MO)3.765.35*0.4122*28*12.8W2(MO)3.675.960.3422*3324.7W3(MO)3.665.560.3825*3523.2different phenolic contents was investigated.MATERIALS AND METHODSW1(C)3.855.380.43375015.1W2(C)4.005.600.29386132.2W3(C)4.015.660.33266428.7W1(MO)3.835.17*0.47374916.6W2(MO)4.005.73*0.32336123.4*W3(MO)4.025.27*0.37296428.4W1(C)3.835.060.42224821.3W2(C)3.835.080.37165141.4W3(C)3.775.090.37166122.3W1(MO)3.79*4.90*0.3414*4632.6*W2(MO)3.804.900.3311*35*45.2W3(MO)3.784.89*0.39*11*38*35.0*aAn asterisk indicates significant differences betweencontrol and microoxygenated wines for each time considered.b Expressed as g/L of tartaric acid.cExpressed as g/L of acetic acid.Wine Samples. Three different red wines, made fromVitis Vinifera var. Monastrell (2005 vintage), differingin their total phenol content, were used for the experiment(W1, W2, and W3). Each wine was distributedinto four 17 500 L tanks, and the MO experimentwas carried out in triplicate, with a control (C) andthree MO tanks for each type of wine. The heightof each tank was 4.5 m, enough for the completedissolution of oxygen microbubbles into the wine.MO began just after alcoholic fermentation had finished(November 7, 2005), applying a oxygen doseof 10 mL/L/month. Malolactic fermentation (MLF)occurred spontaneously. When MLF started (detectedby the decrease in malic acid), the MO systemwas stopped (November 30 for W1 and December20 for W2 and W3). During MLF, the bacteria consumethe acetaldehyde produced. They are capable ofmetabolizing acetaldehyde, even the acetaldehydebound to sulfur dioxide (25); therefore, any excess ofacetaldehyde produced during the MO process willdisappear.When MLF was complete for all wines, SO 2was addedto leave the wines with a free SO 2content close to 30mg/L, and MO was resumed (January 19, 2006). At thismoment, the oxygen supply was reduced to avoidaccumulation of acetaldehyde (3 mL/L/month). After2 months, the oxygen supply was reduced again (1.5mL/L/month) before it was completely stopped. Thewine was analyzed immediately before the MO systembegan (t0), at the beginning of MLF (t1), when MO beganagain after MLF (t2), and 15 days after the MO systemwas stopped (t3) since wines take 8-10 days to absorbthe oxygen, depending on temperature and phenoliccomposition of the wines (26). The MO system (AgrovinS.A., Alcazar de San Juan, Spain) was comprised of anoxygen cylinder (food grade) and a dosing chamberthat allowed the doses of oxygen flowing through ninedifferent microdiffusers to be programmed.General Determinations. pH and titratable aciditywere measured using an automatic titrator (Metrohm,Herisau, Switzerland). Volatile acidity was determinedaccording to the OIV Official Methods (27). Acetaldehydeand malic acid concentration were determinedusing enzymatic test kits from Roche Boehringer,Mannheim, Germany. The SO 2concentration (freeand total) was measured iodometrically by the Ripperprocedure (28) modified to detect the end point potentiometricallywith an automatic titrator (Metrohm,Herisau, Switzerland).Identification and Quantification of Anthocyanins.Wines were analyzed by direct injection of thesamples previously filtered through a 45 μm nylon filter(Teknokroma, Barcelona, Spain). The HPLC analyseswere performed on a Waters 2690 liquid chromatograph(Waters, Milford, MA), equipped with aWaters996 diode array detector and a 250 mm × 4 mm i.d.,5 μm particle size Lichrocart RP-18 column (Merck,Darmstadt, Germany), using as solvents 4.5% aqueousformic acid (solvent A) and acetonitrile (solvent B) at aflow rate of 0.8 mL/ min. Elution was performed witha gradient starting with 10% B to reach 14.5% B at 30min, 15.2% B at 45 min, 18% B at 60 min, 25% B at 100min, and 25-100% B in 30 min. Chromatograms wererecorded at 520 nm.Compounds were identified by comparing their UVspectra recorded with the diode array detector andthose reported in the literature (11, 29). In addition,an HPLC-MS analysis was conducted to confirmeach peak identity. An LC-MSD-Trap VL-01036 liquidchromatograph-ion trap mass detector (Agilent Technologies,Waldbronn, Germany) equipped with anelectrospray ionization (ESI) system was used. Elutionwas performed with the HPLC analysis conditionsdetailed previously. The heated capillary and voltagewere maintained at 350 °C and 4 kV, respectively.Mass scans (MS) were measured from m/z 300-1100.Mass spectrometry data were acquired in the positiveionization mode. Anthocyanins and anthocyanin-92
derived compounds were quantified at 520 nm asmalvidin- 3-glucoside, using malvidin-3-glucosidechloride as an external standard (Extrasynthe`se, Genay,France).Color Determinations in Wines. Absorbance measurementswere made in a Helios Alpha spectrophotometer(Thermo Electron Corp., Waltham, MA) with 0.1,0.2, or 1 cm path length glass cells. Samples were previouslycentrifuged, and the pH was adjusted to 3.6.CIELab parameters were determined by measuringthe transmittance of the wine every 10 nm from 380to 770 nm, using a D65 illuminant and a 10° observer.The L* (measure of lightness), C* (measure of chroma),and H* (hue angle) parameters were determined. Colorintensity (CI), calculated as the sum of absorbanceat 620, 520, and 420 nm, and percentages of red (%R),yellow (%Y), and blue (%B) color were determined accordingto Glories (30); the hue was calculated as theratio between absorbance at 420 nm and absorbanceat 520 nm (31).Total phenols (abs280) were calculated according toRibe´reau Gayon et al. (32). Wine color (WC), total colorof pigments (WCP), and color due to derivatives resistantto SO 2bleaching (CDRSO 2) were determined usinga method adapted from that described by Levengoodand Boulton (33), with all measurements made at 520nm. These parameters were calculated as follows.WC. Twenty microliters of 10% acetaldehyde solutionwas added to 2 mL of a wine sample in a 10 mm plasticcuvette to release any anthocyanins involved in bisulfiteadducts. After 45 min, the sample was placed ina 1 mm cuvette. The reading was corrected to 10 mmpath length by multiplying by 10.WCP. A total of 0.5 mL of wine was diluted in 20 mLof 0.1 N HCl. Absorbance was measured in a 10 mmcuvette after 30 min to ensure complete conversionof anthocyanins into the flavylium form. The readingwas corrected for dilution.CDR SO2 . A total of 160 μL of a 5% SO 2solution (10%potassium metabisulfite solution) was added to 2 mLof the wine sample. After 1 min, the sample was placedin a 2 mm cuvette. The reading was corrected to10 mm path length by multiplying by 5.Determination of Total Tannins. The wine tanninconcentration was evaluated using a protein precipitationassay, with bovine serum albumin (BSA).Sample preparation and a protein precipitation assaywere conducted according to methods described byHarbertson et al. (34). For quantification, results werecompared with a (+)-catechin standard and reportedas mg/L (+)-catechin equivalents.Seminario TécnicoCompuestos azufrados volátiles en vinosAnalysis of Proanthocyanidins. Proanthocyanidincomposition was determinated by HPLC-DAD-MS afterpurification and concentration of the wine extractand acid catalysis in the presence of excess phloroglucinol.The results of phloroglucinolysis providedinformation on the proanthocyanidin subunit composition(terminal and extension unit concentrations)and the mean degree of polymerization (mDP). Theanalyses were carried out in triplicate.The phloroglucinolysis protocol, described by Drinkineet al. (35), included a purification step using C18solid-phase extraction (SPE). Water (15 mL) was addedto 5 mL of wine, and the sample was passed througha preconditioned cartridge. The retained compoundswere eluted with 50 mL of methanol with a flow rateof 2 mL/min. This fraction was dried under reducedpressure and then dissolved in 2 mL of methanol.The second step was the phloroglucinolysis reaction.A solution of 0.2 N HCl in methanol, containing 100g/L phloroglucinol and 20 g/L ascorbic acid, was prepared.A total of 100 μL of the wine sample was reactedwith 100 μL of the phloroglucinol reagent at 50 °Cfor 20 min, and then 1 mL of 80 mM aqueous sodiumacetate was added to stop the reaction.The extension and terminal units resulting fromphloroglucinolysis (catechin, epicatechin, (epi)catechingallate, and (epi)gallocatechin) were determinedby LC-MS. LC-MS analyses were performedon a Micromass Platform II simple quadruple massspectrometer (Micromass- Beckman, Roissy Charlesde-Gaulle,France) equipped with an electrosprayion source. The mass spectrometer was operated innegative-ion mode. The source temperature was 120°C, the capillary voltage was set at 3.5 kV, and thecone voltage was -30 V. HPLC separations were performedon a Hewlett-Packard 1100 series (Agilent,Massy, France) instrument including a pump moduleand a UV detector. Both systems were operatedusing Masslynx 3.4 software. The absorbance was recordedat 280 nm, and mass spectra were recordedfrom 200 to 1200 amu.The elution conditions were wateras follows: aceticacid (99:1; v/v) as solvent A, methyl alcohol as solventB, and the following elution gradient: from 5 to 15% Bin 5 min, 15% B for 2 min, from 15 to 20% B in 3 min,from 20 to 50% B in 10 min, from 50 to 100% B in 2min, and from 100 to 5% B in 2 min, with a flow of 1mL/min. The column used was a reversed-phase 4.6mm × 100 mm i.d., 3.5 μm packing C18 Waters Xterraprotected with a guard column of the same material(Agilent, Saint Quentin-en-Yvelines, France).Statistical Analysis. Significant differences betweenwines and for each variable were assessed with analysisof variance (ANOVA). This statistical analysis, togetherwith a cluster analysis and a principal componentsanalysis, was performed using Statgraphics 5.1(Statistical Graphics Corporation, Rockville, MD).Textos asociados93
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Organizan:Seminario TécnicoCompues
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Seminario TécnicoCompuestos azufra
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01. Relación entre el contenido ni
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02. Los nuevos retosen microbiolog
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02. Los nuevos retos en microbiolog
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03. La microoxigenaciónde vinos ti
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03. La micro-oxigenación de vinos
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03. La micro-oxigenación de vinos
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04. ¡Los compuestosvolátiles no s
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04. ¡Los compuestos volátiles no
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04. ¡Los compuestos volátiles no
Page 42 and 43: Influence of the Timing of Nitrogen
Page 52 and 53: Formación de compuestos volátiles
Page 58 and 59: CapítuloSpiropoulos A, Tanaka J, F
Page 60 and 61: Una revolución en el sector enólo
Page 63 and 64: Nitrogenmanagement iscritical for w
Page 65 and 66: article, when we consider the fl av
Page 67 and 68: y lowering higher alcohols producti
Page 69 and 70: colour composition. Analytical para
Page 71: 21 Henschke, P.A.; Jiranek, V. (199
Page 74 and 75: Unravelling the genetic blueprint o
Page 77 and 78: When the heat is on,yeast fermentat
Page 79 and 80: Even when microbes were kept in che
Page 81: Seminario TécnicoCompuestos azufra
Page 84 and 85: Taking control of alcoholEthanol [%
Page 87 and 88: A la recerca del codidigital dels l
Page 89: Seminario TécnicoCompuestos azufra
Page 94 and 95: Effect of Micro-oxygenation on Colo
Page 104 and 105: Capítuloentre las uniones de las d
Page 106 and 107: CapítuloSISTEMADEALIMENTACIÓNBOMB
Page 108 and 109: CapítuloGráfico 4.- Evolución de
Page 110: Capítulo(20) Es-Safin.E, Fulcrand
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