Table 2.
Phenolic profile of grape pomace extract (GPE) from Cabernet Sauvignon, Merlot wine (WC), and enriched wines at 4.23 (W4) and 7.89 (W8) g GAE/L.
| Compound | GPE (mg/g Extract) | WC (mg/L) | W4 (mg/L) | W8 (mg/L) |
|---|---|---|---|---|
| Hydroxybenzoic acids | ||||
| Gallic acid | 0.50 ± 0.03 | 12.05 ± 1.09 a | 10.51 ± 0.30 a | 4.90 ± 2.81 b |
| 3-methyl-gallic acid | N.D. | <L.O.Q. | <L.O.Q. | <L.O.Q. |
| 4-methyl-gallic acid | <L.O.Q. | N.D. | <L.O.Q. | 3.40 ± 0.05 |
| Octyl-gallate | <L.O.Q. | 2.06 ± 0.02 b | 2.11± 0.04 b | 3.90 ± 0.03 a |
| Pyrogallol | 0.34 ± 0.01 | N.D. | 5.07 ± 0.05 a | 5.66 ± 0.37 a |
| Gentisic acid | N.D. | <L.O.Q. | <L.O.Q. | <L.O.Q. |
| p-hydroxybenzoic acid | 0.28 ± 0.01 | <L.O.Q. | N.D. | <L.O.Q. |
| Protocatechuic acid | N.D. | 2.58 ± 0.13 b | 2.92 ± 0.12 b | 6.55 ± 0.40 a |
| Syringic acid | 0.20 ± 0.00 | 6.20 ± 0.19 c | 7.66 ± 0.30 b | 16.04 ± 0.10 a |
| Ellagic acid | 0.40 ± 0.00 | 2.88 ± 0.08 c | 3.52 ± 0.07 b | 13.56 ± 0.27 a |
| Vanillic acid | N.D. | <L.O.Q. | <L.O.Q. | <L.O.Q. |
| Vanillic acid glucoside | <L.O.Q. | N.D. | <L.O.Q. | 3.54 ± 0.01 |
| Homovanillic acid | N.D. | 2.80 ± 0.17 b | 2.54 ± 0.05 b | 4.63 ± 0.21 a |
| Vainilloside | N.D. | N.D. | <L.O.Q. | N.D. |
| Hydroxycinnamic acids | ||||
| Caffeic acid | <L.O.Q. | 16.22 ± 0.44 b | 16.24 ± 0.43 b | 25.27 ± 1.44 a |
| Caffeoyl-malate | N.D. | <L.O.Q. | N.D. | N.D. |
| Methyl-ferulate | <L.O.Q. | 5.08 ± 0.09 b | 4.92 ± 0.10 b | 8.94 ± 0.22 a |
| m-coumaric acid | N.D. | <L.O.Q. | <L.O.Q. | <L.O.Q. |
| p-coumaric acid | N.D. | 0.59 ± 0.01 | <L.O.Q. | <L.O.Q. |
| Stilbenes | ||||
| Resveratrol | N.D. | <L.O.Q. | N.D. | 11.32 ± 0.03 |
| Dihydroresveratrol | N.D. | N.D. | N.D. | <L.O.Q. |
| Resveratrol-glucoside | N.D. | <L.O.Q. | <L.O.Q. | <L.O.Q. |
| Piceatannol | N.D. | <L.O.Q. | N.D. | <L.O.Q. |
| Astringin | N.D. | <L.O.Q. | <L.O.Q. | <L.O.Q. |
| ε-Viniferin | N.D. | N.D. | <L.O.Q. | <L.O.Q. |
| δ-Viniferin | N.D. | N.D. | N.D. | <L.O.Q. |
| Resveratrol dimer | N.D. | N.D. | N.D. | <L.O.Q. |
| Phenylethanoids | ||||
| Tyrosol | N.D. | ID | ID | ID |
| Hydroxytyrosol | N.D. | ID | N.D. | N.D. |
| Coumarins | ||||
| Esculetin | ID | ID | ID | ID |
| Esculetin glucoside | N.D. | N.D. | ID | N.D. |
| Flavones | ||||
| Luteolin | <L.O.Q. | N.D. | N.D. | <L.O.Q. |
| Equol | N.D. | N.D. | N.D. | <L.O.Q. |
| Tetrahydroxyisoflavone | <L.O.Q. | N.D. | N.D. | 20.26 ± 0.04 |
| Pentahydroxyisoflavone | <L.O.Q. | N.D. | N.D. | 20.39 ± 0.02 |
| Flavanones | ||||
| Eriodictyol | 0.35 ± 0.00 | 2.31 ± 0.00 b | 2.24 ± 0.05 b | 4.51 ± 0.07 a |
| Eriodictyol-7-glucoside | 0.35 ± 0.00 | 2.45 ± 0.00 b | N.D. | 5.01 ± 0.02 a |
| Homoeriodictyol | N.D. | 2.22 ± 0.01 | N.D. | N.D. |
| Hesperetin | N.D. | N.D. | 2.21 ± 0.00 b | 4.38 ± 0.02 a |
| Naringenin | 1.40 ± 0.10 | N.D. | N.D. | 48.33 ± 0.86 |
| Naringenin glucoside | N.D. | 7.02 ± 0.14 b | N.D. | 20.19 ± 1.03 a |
| Naringin | N.D. | 203.88 ± 9.43 a | 177.34 ± 5.59 b | 219.06 ± 7.55 a |
| Flavonols | ||||
| Astilbin | 1.79 ± 0.00 | 13.26 ± 0.04 b | 13.32 ± 0.05 b | 25.94 ± 0.11 a |
| Isorhamnetin | 1.83 ± 0.01 | <L.O.Q. | 11.23 ± 0.01 b | 29.96 ± 0.10 a |
| Isorhamnetin glucoside | 1.90 ± 0.01 | N.D. | 11.84 ± 0.04 b | 25.82 ± 0.15 a |
| Kaempferol | N.D. | N.D. | N.D. | 24.07 ± 0.03 |
| Kaempferol-3-glucoside | N.D. | N.D. | 10.31 ± 0.05 b | 21.42 ± 0.06 a |
| Kaempferol-7-glucuronide | N.D. | N.D. | N.D. | <L.O.Q. |
| Laricitrin | N.D. | N.D. | N.D. | 23.88 ± 0.08 |
| Laricitrin-3-glucoside | 1.87 ± 0.01 | 11.42 ± 0.02 c | 12.12 ± 0.03 b | 25.75 ± 0.09 a |
| Myricetin | <L.O.Q. | N.D. | N.D. | 29.06 ± 0.24 |
| Quercetin | 1.94 ± 0.03 | 11.33 ± 0.01 b | 11.40 ± 0.01 b | 52.89 ± 0.33 a |
| Quercetin-3-galactoside | 2.06 ± 0.02 | N.D. | 13.20 ± 0.04 b | 31.72 ± 0.11 a |
| Quercetin-3-glucuronide | 2.08 ± 0.04 | 13.35 ± 0.04 c | 16.85 ± 0.09 b | 40.43 ± 0.33 a |
| Syringetin | 1.78 ± 0.00 | <L.O.Q. | <L.O.Q. | 24.15 ± 0.05 |
| Syringetin-3-glucoside | 2.05 ± 0.03 | 13.06 ± 0.06 c | 14.35 ± 0.08 b | 31.85 ± 0.06 a |
| Taxifolin | 1.79 ± 0.00 | 11.38 ± 0.02 c | 11.58 ± 0.06 b | 23.86 ± 0.15 a |
| Flavan-3-ols | ||||
| Catechin | 1.68 ± 0.13 | 3.37 ± 0.13 c | 9.00 ± 0.17 b | 41.50 ± 3.08 a |
| 3-methyl-catechin | N.D. | 0.97 ± 0.02 b | N.D. | 1.93 ± 0.05 a |
| Gallocatechin | N.D. | 0.70 ± 0.04 a | N.D. | 1.16 ± 0.12 a |
| Epicatechin | 0.55 ± 0.04 | 2.64 ± 0.04 c | 7.67 ± 0.11 b | 25.11 ± 0.40 a |
| Epicatechin-3-glucuronide | <L.O.Q. | 0.84 ± 0.01 b | 0.95 ± 0.05 a | 1.82 ± 0.07 a |
| Epicatechin gallate | <L.O.Q. | N.D. | N.D. | 4.93 ± 0.08 |
| Epigallocatechin | N.D. | N.D. | N.D. | <L.O.Q. |
| Procyanidin B1 | 0.51 ± 0.10 | 1.64 ± 0.08 b | 2.12 ± 0.16 b | 15.49 ± 3.62 a |
| Procyanidin B2 | 0.35 ± 0.03 | 1.81 ± 0.06 c | 13.64 ± 0.12 b | 45.86 ± 4.82 a |
| Procyanidin B3 | 0.98 ± 0.13 | N.D. | 3.12 ± 0.07 a | 6.96 ± 1.69 a |
| Procyanidin B4 | 0.17 ± 0.03 | N.D. | 1.34 ± 0.17 a | 3.15 ± 0.79 a |
| Procyanidin C1 | 0.44 ± 0.06 | N.D. | 4.17 ± 0.62 b | 19.27 ± 1.51 a |
| Procyanidin C2 | 0.40 ± 0.03 | N.D. | 1.64 ± 0.69 b | 5.39 ± 0.62 a |
| Total phenolic compounds | 27.99 | 354.11 | 407.13 | 1033.21 |
Results express the mean ± SD of three independent experiments. Different letters express significant difference among wine samples at p < 0.05. N.D. = not detected compound. I.D. = Identified compound but not quantified. <L.O.Q. = under limit of quantification.