Table 6.

Summary of techniques and methods applied for the quantification of phenolic compounds on wine.

Technique	Method	Phenolic Concentration (mg/L)	References
Spectroscopic techniques—Folin Ciocalteu methodology	Method 1: For the analysis of total polyphenol contents, wine samples were diluted with ultrapure water (1:100) and the absorbance was measured at 280 nm using a spectrophotometer. The value of I280 was calculated as the absorbance × 100. For the determination of Folin–Ciocalteu Index (FCI). Wine was diluted 1:5 in ultrapure water. Then, 0.1 mL volume of wine sample, 5 mL of distilled water, 0.5 mL of Folin–Ciocalteu reagent, and 2 mL of 20% w/w sodium carbonate solution were placed in a 10 mL calibrated flask, diluted to volume with distilled water and allowed to stand for 30 min before measuring the absorbance at 765 nm.	Total polyphenol index: Joven (D.O. Ribera) (67), Crianza (D.O. Ribera) (64), Gran Reserva (D.O. Ribera) (56), Joven (D.O. Toro) (82), Crianza (D.O. Toro) (64), Reserva (D.O. Toro) (58), Reserva (D.O. Rioja) “Syrah” (57), and Reserva (D.O. Rioja) “Coupage” (59). Folin–Ciocalteu Index: Joven (D.O. Ribera) (73), Crianza (D.O. Ribera) (69), Gran Reserva (D.O. Ribera) (61), Joven (D.O. Toro) (81), Crianza (D.O. Toro) (70), Reserva (D.O. Toro) (65), Reserva (D.O. Rioja) “Syrah” (57), and Reserva (D.O. Rioja) “Coupage” (64).	[209]
	Method 2: The microchip was designed containing three inlets: two for reagents (Folin–Ciocalteu and NaOH) and a third one to inject the sample. Two optical fibers using guides located parallel or perpendicular to the flow outlet were inserted into the microchip. In addition, a 6 V and 10 W halogen lamp with an optical path length of 7 mm between optical fibers was used. The microchannel width ranged from 70 to 120 lm in different microchips.	Total polyphenols concentration: Chenin blanc (2.14), Chardonnay (1.89), and Sauvignon blanc (2.56).	[210]
GC/MS	Method 3: Injection port at 250 °C. Capillary column (30 m × 0.25 mm, 0.25 µm) with helium at a constant flow of 1 mL/min. Oven temperature at 70 °C for 1 min, then increased to 280 °C at 10 °C/min and maintained for 5 min. Total time of separation: 27 min. The temperatures of the MS transfer line, ion source, and detector were fixed at 300, 230 and 150 °C. The MS was operated in positive mode (electron energy 70 eV). Full-scan acquisition was performed with mass detection range set at m/z 400–600.	Red: protocatechuic acid (1.08), p-coumaric acid (0.96), gallic acid (0.99), ferulic acid (1.03), caffeic acid (1.01), sinapic acid (1.07), pterostilbene (1.02), resveratrol (1.15), (+)-catechin (1.07). White: protocatechuic acid (1.12), p-coumaric acid (1.08), gallic acid (0.85), ferulic acid (0.98), caffeic acid (1.04), sinapic acid (1.05), pterostilbene (1.01), resveratrol (1.00), (+)-catechin (0.95). Rosé: protocatechuic acid (1.09), p-coumaric acid (0.90), gallic acid (1.03), ferulic acid (1.00), caffeic acid (0.99), sinapic acid (1.04), pterostilbene (0.97), resveratrol (0.96), (+)-catechin (1.03).	[201]
HPLC	Method 4: Reversed-phase 80 Å LC Column (250 × 4.6 mm, 4 μm) at 30 °C. Mobile phase water/formic acid/acetonitrile A (87:10:3) and B (40:10:50). Gradient programme: from 6 to 20% B (20 min), from 20 to 40% B (15 min), from 40 to 60% B (5 min), from 60 to 90% B (5 min), isocratic 90 B (5 min), from 90 to 6% B (0.5 min), isocratic 6% B (22.5 min). Flow rate 500 μL/min. Total analysis 73 min. Chromatograms were recorded at 280, 330, and 520 nm.	Harvest 2010: gallic acid (0.81), protocatechuic acid (6.02), caftaric acid (25.40), coutaric acid (12.60), caffeic acid (2.58), p-coumaric acid (2.01), ferulic acid (0.53), sinapic acid (0.18), procyanidin B1 (1.25), catechin (7.04), procyanidin B2 (3.39), epigallocatechin gallate (2.78), epicatechin (30.90), gallocatechin gallate (11.40), epicatechin gallate (3.70), catechin gallate (1.30), procyanidin A2 (1.84), quercetin-3-O-galactoside (0.53), quercetine-3-O-glucoside (0.87), kaempferol-3-O-rutinoside (3.68), and myricetin (1.58). Harvest 2011: gallic acid (0.14), protocatechuic acid (9.33), caftaric acid (23.90), coutaric acid (7.03), caffeic acid (2.92), p-coumaric acid (0.46), ferulic acid (0.52), sinapic acid (0.04), procyanidin B1 (1.23), catechin (3.92), procyanidin B2 (4.01), epigallocatechin gallate (1.25), epicatechin (61.60), gallocatechin gallate (12.70), epicatechin gallate (2.91), catechin gallate (1.37), procyanidin A2 (4.66), quercetin-3-O-galactoside (0.64), quercetine-3-O-glucoside (0.62), kaempferol-3-O-rutinoside (4.13), and myricetin (1.67). Harvest 2012: gallic acid (0.40), protocatechuic acid (7.00), caftaric acid (13.80), coutaric acid (4.88), caffeic acid (2.77), p-coumaric acid (2.82), ferulic acid (0.31), sinapic acid (0.03), procyanidin B1 (1.63), catechin (6.31), procyanidin B2 (4.93), epigallocatechin gallate (1.22), epicatechin (20.40), gallocatechin gallate (12.20), epicatechin gallate (3.53), catechin gallate (2.08), procyanidin A2 (1.79), quercetin-3-O-galactoside (0.80), quercetine-3-O-glucoside (0.53), kaempferol-3-O-rutinoside (1.99), myricetin (1.48), quercetin (1.64), and trans-piceid (0.001). Harvest 2013: gallic acid (27.80), protocatechuic acid (5.31), caftaric acid (45.50), coutaric acid (16.50), caffeic acid (2.21), p-coumaric acid (0.66), ferulic acid (0.48), sinapic acid (0.08), procyanidin B1 (1.32), catechin (8.95), procyanidin B2 (3.70), epigallocatechin gallate (1.59), epicatechin (4.09), gallocatechin gallate (9.59), epicatechin gallate (5.07), catechin gallate (1.94), procyanidin A2 (1.54), quercetin-3-O-galactoside (0.77), quercetine-3-O-glucoside (0.58), kaempferol-3-O-rutinoside (4.42), myricetin (1.53), trans-piceid (0.0145), and cis-piceid (0.030). Harvest 2014: gallic acid (14.2), protocatechuic acid (7.10), caftaric acid (35.4), coutaric acid (7.30), caffeic acid (6.70), p-coumaric acid (4.61), ferulic acid (0.41), sinapic acid (0.04), procyanidin B1 (1.31), catechin (12.10), procyanidin B2 (5.14), epigallocatechin gallate (1.17), epicatechin (6.40), gallocatechin gallate (4.11), epicatechin gallate (6.11), catechin gallate (1.85), procyanidin A2 (1.94), quercetin-3-O-galactoside (0.46), quercetine-3-O-glucoside (0.63), kaempferol-3-O-rutinoside (2.14), myricetin (1.45), trans-piceid (0.10), and cis-piceid (0.10). Harvest 2015: gallic acid (11.90), protocatechuic acid (3.88), caftaric acid (54.80), coutaric acid (13.30), caffeic acid (4.00), p-coumaric acid (1.23), ferulic acid (0.27), sinapic acid (0.15), procyanidin B1 (2.04), catechin (8.69), procyanidin B2 (3.02), epigallocatechin gallate (2.04), epicatechin (3.06), gallocatechin gallate (10.20), epicatechin gallate (7.30), catechin gallate (2.24), procyanidin A2 (1.17), quercetin-3-O-galactoside (1.27), quercetine-3-O-glucoside (0.40), kaempferol-3-O-rutinoside (0.36), myricetin (1.45), quercetin (1.56), trans-piceid (0.01), and cis-piceid (0.06).	[216]
	Method 5: First, 20 µL sample injected into HPLC-UV-Vis. 4 µm Nova Pak C18 (300 mm × 3.9 mm) column. Phase A: water-formic acid (98:2 v/v). Phase B: 70% of MeOH + 2% formic acid + 30% of solvent A. Flow: 0.8 mL/min. Gradient elution programme: 3 min at 0% B, to 10% B (7 min), to 40% B (50 min), to 60% B (20 min), to 100% B (20 min), and 10 min at 100% B.	Allier: HMF (4.08), furfural (1.09), vanillin (10.10), syringaldehyde (11.50), and ellagic acid (4.74). Never: HMF (3.53), furfural (0.80), vanillin (8.28), syringaldehyde (13.10), and ellagic acid (8.60). Tronçais: HMF (3.93), furfural (1.12), vanillin (7.21), syringaldehyde (11.80), and ellagic acid (3.79). Limousin: HMF (3.67), furfural (0.82), vanillin (9.72), syringaldehyde (15.20), and ellagic acid (5.55).	[186]
UPLC/ UPLC-MS/MS	Method 6: 25 mL of wine diluted 4 times with deionized water and loaded in C18-SPE cartridge (later washed with 6 mL of 0.3% aqueous perchloric acid and 10 mL of methanol). Evaporation of the eluate was at 30 °C, and reconstituted in 1 mL of methanol/water (1:1). Filtered through a 0.22 μm PTFE filter prior to injection. 2 μL were injected by an auto-sampler at 6 °C. Reverse phase Acquity HSS T3 column (1.8 μm, 100 mm × 2.1 mm) used at 40 °C. Flow of 0.4 mL/min. Mobile phase A: water + 0.1% formic acid and Mobile phase B: acetonitrile + 0.1% formic acid. The gradient was 5% B (0 min), to 20% B (3 min), constant until 4.3 min, followed by gradient to 45% B (9 min), and to 100% (11 min). Constant gradient 100% for 2 min and back to initial position in 2 min. Xevo TQ MS system with electrospray positive ionization mode. Capillary voltage at 0.5 kV Block and desolvation temperatures: 150 and 500 °C. Desolvation gas flow was 1000 L/h and cone gas flow 20 L/h.	Teran: delphinidin 3-O-glucoside (9.25), cyanidin 3-O-glucoside (2.02), petunidin 3-O-glucoside (30.90), peonidin 3-O-glucoside (16.16), malvidin 3-O-glucoside (122.10), delphinidin 3-(6″-acetyl)-glucoside (3.35), cyanidin 3-(6″-acetyl)-glucoside (1.74), petunidin 3-(6″-acetyl)-glucoside (8.79), peonidin 3-(6″-acetyl)-glucoside (6.53), malvidin 3-(6″-acetyl)-glucoside (31.22), delphinidin 3-(6″-p-coumaroyl)-glucoside (0.53), cyanidin 3-(6″-p-coumaroyl)-glucoside (0.37), petunidin 3-(6″-p-coumaroyl)-glucoside (0.90), peonidin 3-(6″-p-coumaroyl)-glucoside (1.32), malvidin 3-(6″-p-coumaroyl)-glucoside (11.22), p-hydroxybenzoic acid (0.50), vanillic acid (0.71), gallic acid (36.89), 2,5-dihydroxybenzoic acid (0.50), methyl gallate (0.04), ellagic acid (2.93), caffeic acid (1.00), ferulic acid (0.12), trans-caftaric acid (33.04), trans-fertaric acid (2.91), trans-coutaric acid (12.00), trans-piceid (2.19), cis-piceid (19.71), astringin (0.79), isorhapontin (0.24), pallidol (1.19) isohopeaphenol (0.92), catechin (40.05), epicatechin (18.85), epigallocatechin (2.77), gallocatechin (4.18), procyanidin B1 (69.63), procyanidin B2 + B4 (46.78), procyanidin B3 (17.00), quercetin (0.27), taxifolin (0.65), myricetin (1.78), laricitrin (1.32), and quercetin 3-rhamnoside (0.01). Plavac mali: delphinidin 3-O-glucoside (5.02), cyanidin 3-O-glucoside (0.94), petunidin 3-O-glucoside (17.40), peonidin 3-O-glucoside (7.47), malvidin 3-O-glucoside (82.47), delphinidin 3-(6″-acetyl)-glucoside (0.40), cyanidin 3-(6″-acetyl)-glucoside (0.22), petunidin 3-(6″-acetyl)-glucoside (1.31), peonidin 3-(6″-acetyl)-glucoside (1.15), malvidin 3-(6″-acetyl)-glucoside (8.04), delphinidin 3-(6″-p-coumaroyl)-glucoside (0.53), cyanidin 3-(6″-p-coumaroyl)-glucoside (0.22), petunidin 3-(6″-p-coumaroyl)-glucoside (0.68), peonidin 3-(6″-p-coumaroyl)-glucoside (0.84), malvidin 3-(6″-p-coumaroyl)-glucoside (10.41), p-hydroxybenzoic acid (0.72), vanillic acid (0.69), gallic acid (41.52), 2,5-dihydroxybenzoic acid (0.14), methyl gallate (0.03), ellagic acid (3.19), caffeic acid(1.00), ferulic acid (0.25), trans-caftaric acid (33.66), trans-fertaric acid (3.77), trans-coutaric acid (10.81), trans-piceid (1.93), cis-piceid (11.56), astringin (0.97), isorhapontin (0.35), pallidol (0.98), isohopeaphenol (1.28), catechin (47.69), epicatechin (15.59), epigallocatechin (3.96), gallocatechin (16.35), procyanidin B1 (90.96), procyanidin B2 + B4 (37.54), procyanidin B3 (14.38), kaempferol (0.02), quercetin (0.31), taxifolin (9.60), myricetin (1.00), laricitrin (1.21), quercetin 3-O-rhamnoside (0.47), and myricitrin (0.36). Merlot: delphinidin 3-O-glucoside (9.51), cyanidin 3-O-glucoside (1.45), petunidin 3-O-glucoside (25.06), peonidin 3-O-glucoside (9.98), malvidin 3-O-glucoside (92.08), delphinidin 3-(6″-acetyl)-glucoside (3.23), cyanidin 3-(6″-acetyl)-glucoside (1.40), petunidin 3-(6″-acetyl)-glucoside (6.86), peonidin 3-(6″-acetyl)-glucoside (4.91), malvidin 3-(6″-acetyl)-glucoside (24.49), delphinidin 3-(6″-p-coumaroyl)-glucoside (0.62), cyanidin 3-(6″-p-coumaroyl)-glucoside (0.42), petunidin 3-(6″-p-coumaroyl)-glucoside (0.81), peonidin 3-(6″-p-coumaroyl)-glucoside (1.27), malvidin 3-(6″-p-coumaroyl)-glucoside (9.96), p-hydroxybenzoic acid (0.42), vanillic acid (0.67), gallic acid (31.73), 2,5-dihydroxybenzoic acid (0.28), methyl gallate (0.04), ellagic acid (2.62), caffeic acid (0.47), ferulic acid (0.04), trans-caftaric acid (24.23), trans-fertaric acid (1.36), trans-coutaric acid (8.11), trans-piceid (1.93), cis-piceid(16.42), astringin (0.79), isorhapontin (0.17), pallidol (0.40), isohopeaphenol (0.28), catechin (41.96), epicatechin (18.18), epigallocatechin (4.72), gallocatechin (8.03), procyanidin B1 (68.16), procyanidin B2 + B4 (39.33), procyanidin B3 (39.33), kaempferol (39.33), quercetin (0.34), taxifolin (1.44), myricetin (1.44), laricitrin (1.04), quercetin 3-O-rhamnoside (0.03), myricitrin (0.10). Cabernet sauvignon: delphinidin 3-O-glucoside (10.01), cyanidin 3-O-glucoside (1.11), petunidin 3-O-glucoside (20.86), peonidin 3-O-glucoside (7.18), malvidin 3-O-glucoside (92.41), delphinidin 3-(6″-acetyl)-glucoside (4.17), cyanidin 3-(6″-acetyl)-glucoside (1.30), petunidin 3-(6″-acetyl)-glucoside (7.73), peonidin 3-(6″-acetyl)-glucoside (4.21), malvidin 3-(6″-acetyl)-glucoside (33.48), delphinidin 3-(6″-p-coumaroyl)-glucoside (0.26), cyanidin 3-(6″-p-coumaroyl)-glucoside (0.13), petunidin 3-(6″-p-coumaroyl)-glucoside (0.26), peonidin 3-(6″-p-coumaroyl)-glucoside (0.65), malvidin 3-(6″-p-coumaroyl)-glucoside (8.29), p-hydroxybenzoic acid (0.43), vanillic acid (0.46), gallic acid (28.84), 2,5-dihydroxybenzoic acid (0.31), methyl gallate (0.02), ellagic acid (4.20), caffeic acid (1.58), ferulic acid (0.06), trans-caftaric acid (33.00), trans-fertaric acid (1.45), trans-coutaric acid (13.30), trans-piceid (0.78), cis-piceid (6.63), astringin (0.36), isorhapontin (0.07), pallidol (0.23), isohopeaphenol (0.26), catechin (40.32), epicatechin (13.94), epigallocatechin (3.62), gallocatechin (10.27), procyanidin B1 (71.18), procyanidin B2 + B4 (34.63), procyanidin B3 (14.24), kaempferol (0.02), quercetin (0.48), taxifolin (1.33), myricetin (1.83), laricitrin (1.50), quercetin 3-O-rhamnoside (0.06), myricitrin (0.09).	[219]
	Method 7: The fruit was destemmed and crushed to obtain must. -Sample without any treatment: control sample. -Microwave treatment: for eight minutes (1200 W reaching 80 °C) -Thermo-maceration: the must was heated to 80 °C for eight minutes. -Enzymatic treatment: the must was treated with pectolytic enzyme- Siha Pectinase at a dose of 0.05 mg/L, for 1 h at 50 °C, and stirred every 15 min. Then, must was heated to 65 °C for 2 min to denature the enzyme. For the analysis, the samples were filtered through a 0.22 μm membrane and analyzed by means of an Acquity UPLC system with a PDA detector. An Acquity UPLC BEH C18 column (2.1 × 100 mm, 1.7 μm) at 30 °C was used. Next, 5 μL of sample was injected to the system at a flow rate of 0.43 mL/min. Mobile phase A: deionized water + 4.5% formic acid Mobile phase B: acetonitrile + 4.5% formic acid. Gradient: 1% B (0 min), to 25% B (12 min), and to 100% B (12.5 min). Back to initial conditions in 1 min.	Must: Control: anthocyanins (1.03), flavonols (0.22), phenolic acids (2.20), flavan-3-ols (26.54), and total phenolic (29.99). Microwave: anthocyanins (12.38), flavonols (2.19), phenolic acids (1.26), flavan-3-ols (27.59), and total phenolic (43.42). Thermo-maceration: anthocyanins (3.84), flavonols (2.41), phenolic acids (2.55), flavan-3-ols (23.15), and total phenolic (31.95). Enzymatic: anthocyanins (3.02), flavonols (0.62), phenolic acids (1.45), flavan-3-ols (28.96), and total phenolic (34.08). Wine after fermentation: Control: anthocyanins (0.38), flavonols (0.08), phenolic acids (0.41), flavan-3-ols (19.45), and total phenolic (20.32). Microwave: anthocyanins (1.01), flavonols (0.23), phenolic acids (0.88), flavan-3-ols (19.61), and total phenolic (21.73). Thermo-maceration: anthocyanins (0.71), flavonols (0.10), phenolic acids (0.63), flavan-3-ols (20.18), and total phenolic (21.62). Enzymatic: anthocyanins (0.44), flavonols (0.09), phenolic acids (0.41), flavan-3-ols (19.18), and total phenolic (20.12). Wine after maturation (six months): Control: anthocyanins (0.12), flavonols (0.04), phenolic acids (0.47), flavan-3-ols (19.55), and total phenolic (20.18). Microwave: anthocyanins (0.53), flavonols (0.11), phenolic acids (0.82), flavan-3-ols (20.22), and total phenolic (21.68). Thermo-maceration: anthocyanins (0.38), flavonols (0.09), phenolic acids (0.65), flavan-3-ols (19.26), and total phenolic (20.38). Enzymatic: anthocyanins (0.08), flavonols (0.02), phenolic acids (0.39), flavan-3-ols (19.48), and total phenolic (19.97).	[126]
Etongue	Method 8: 26 potentiometric chemical sensors: plasticized PVC sensors displaying sensitivity to organic anions and phenols and to organic cations; chalcogenide glass sensors displaying redox response and a conventional glass pH electrode. Responses of the sensor array were measured vs. conventional Ag/AgCl reference electrode.	Madeira wine: protocatechuic acid (4.66), catechin (0.76), vanillinic acid (3.23), vanillin (1.38), sinapic acid (1.32), and trans-resveratrol (0.23).	[220]