Table 2.
Relative abundance of volatile metabolites in commercial balsamic vinegars.
| Metabolite | RT (min) | m/z | Ag RSD (%), n = 6 | Relative Abundance in Vinegar Samples | |||||
|---|---|---|---|---|---|---|---|---|---|
| D | M1 | L | T | M4 | P | ||||
| Volatile acids (14): | |||||||||
| 2-Ethylhexanoic acid | 9.18 | 88 | 6 | ND | ND | ND | 0.19 | ND | ND |
| 2-Methybutyric acid | 6.59 | 74 | 7 | 0.23 ± 0.04 | 0.16 ± 0.02 | 0.26 ± 0.05 | 0.29 ± 0.08 | 0.24 ± 0.02 | 0.23 ± 0.04 |
| 4-Methyl-2-pentenoic acid | 7.59 | 60 | 8 | 0.03 ± 0.00 | ND | 0.04 ± 0.01 | 0.05 ± 0.01 | ND | 0.03 ± 0.00 |
| Acetic acid | 4.43 | 43 | 4 | 2.26 ± 0.56 | 2.25 ± 0.76 | 2.20 ± 0.12 | 2.33 ± 0.09 | 2.20 ± 0.15 | 2.26 ± 0.23 |
| Benzeneacetic acid | 11.13 | 91 | 7 | 0.27 ± 0.12 | 0.06 ± 0.01 | 0.31 ± 0.09 | 0.74 ± 0.17 | 0.42 ± 0.12 | 0.52 ± 0.23 |
| Butyric acid | 4.46 | 60 | 7 | 0.58 ± 0.11 | 0.54 ± 0.16 | 0.40 ± 0.09 | 0.09 ± 0.02 | 0.05 ± 0.00 | 0.17 ± 0.04 |
| Carbolic acid | 8.56 | 94 | 9 | 0.05 ± 0.01 | 0.04 ± 0.00 | 0.01 ± 0.00 | 0.10 ± 0.02 | ND | 0.03 ± 0.00 |
| Furoic acid | 9.75 | 112 | 8 | 0.41 ± 0.18 | 0.41 ± 0.11 | 0.38 ± 0.09 | 0.23 ± 0.04 | 0.13 ± 0.03 | 0.21 ± 0.07 |
| Hexanoic acid | 8.00 | 60 | 5 | 0.33 ± 0.11 | 0.27 ± 0.06 | 0.24 ± 0.03 | 0.17 ± 0.05 | 0.23 ± 0.08 | 0.44 ± 0.11 |
| Isobutyric acid | 5.44 | 73 | 6 | 1.04 ± 0.34 | 0.45 ± 0.11 | 1.04 ± 0.30 | 0.84 ± 0.13 | 0.02 ± 0.00 | 0.74 ± 0.21 |
| Isovaleric acid | 6.98 | 60 | 4 | 2.15 ± 0.67 | 1.99 ± 0.44 | 3.09 ± 0.81 | 5.31 ± 0.96 | 0.11 ± 0.01 | 3.46 ± 0.54 |
| Octanoic acid | 10.13 | 73 | 8 | 0.25 ± 0.04 | 0.34 ± 0.02 | 0.19 ± 0.01 | ND | 0.22 ± 0.03 | 0.18 ± 0.03 |
| Propionic acid | 5.28 | 74 | 4 | 0.84 ± 0.55 | 0.46 ± 0.10 | 0.54 ± 0.18 | 0.18 ± 0.05 | 0.25 ± 0.05 | 0.14 ± 0.04 |
| Valeric acid | 7.44 | 60 | 6 | 0.23 ± 0.04 | 0.08 ± 0.01 | 0.05 ± 0.00 | ND | ND | 0.37 ± 0.06 |
| Esters (12): | |||||||||
| 2-Carboxymethyl-3-n-hexylmaleic acid anhydride | 12.47 | 126 | 7 | 0.22 ± 0.05 | 0.21 ± 0.02 | 0.31 ± 0.05 | 0.12 ± 0.01 | 0.15 ± 0.03 | 0.31 ± 0.08 |
| (−)-Ethyl L-Lactate | 5.65 | 45 | 7 | 0.08 ± 0.02 | 0.39 ± 0.14 | 0.12 ± 0.05 | 0.10 ± 0.01 | 0.04 ± 0.00 | 0.12 ± 0.02 |
| 2-Methyl-1-butyl acetate | 5.37 | 70 | 6 | 0.10 ± 0.02 | 0.17 ± 0.03 | 0.07 ± 0.00 | 0.08 ± 0.02 | 0.01 ± 0.00 | 0.06 ± 0.01 |
| 1,3-Propylene diacetate | 8.76 | 43 | 9 | 0.17 ± 0.05 | 0.05 ± 0.00 | 0.05 ± 0.00 | 0.06 ± 0.01 | 0.16 ± 0.05 | 0.03 ± 0.00 |
| Diethyl succinate | 9.59 | 129 | 5 | 0.41 ± 0.17 | 0.71 ± 0.26 | 0.87 ± 0.21 | 0.15 ± 0.05 | 0.03 ± 0.00 | 0.14 ± 0.03 |
| Ethylisovalerate | 4.91 | 40 | 9 | 0.01 ± 0.00 | ND | 0.01 ± 0.00 | 0.01 ± 0.00 | 0.02 ± 0.00 | 0.01 ± 0.00 |
| Ethyl hydrogen succinate | 10.47 | 101 | 4 | 2.10 ± 0.23 | 1.89 ± 0.55 | 2.28 ± 0.38 | 2.32 ± 0.43 | 1.26 ± 0.17 | 1.17 ± 0.17 |
| Isoamyl acetate | 5.34 | 43 | 6 | 0.83 ± 0.34 | 1.65 ± 0.33 | 0.61 ± 0.09 | 0.09 ± 0.00 | 0.16 ± 0.03 | 0.42 ± 0.11 |
| Methyl 2-furoate | 4.98 | 95 | 8 | 0.03 ± 0.00 | 0.02 ± 0.00 | 0.01 ± 0.00 | 0.01 ± 0.00 | 0.04 ± 0.01 | 0.01 ± 0.00 |
| Methylsuccinic anhydride | 9.52 | 42 | 4 | 0.04 ± 0.00 | 0.04 ± 0.00 | 0.03 ± 0.01 | ND | 0.03 ± 0.00 | ND |
| Phenethyl acetate | 10.29 | 104 | 8 | 0.44 ± 0.17 | 0.44 ± 0.11 | 0.55 ± 0.08 | 0.24 ± 0.04 | 0.12 ± 0.02 | 0.21 ± 0.06 |
| p-Hydroxycinnamic acid, ethyl ester | 15.98 | 147 | 7 | 0.01 ± 0.00 | 0.04 ± 0.00 | 0.16 ± 0.05 | 0.06 ± 0.00 | 0.14 ± 0.03 | 0.05 ± 0.00 |
| Higher alcohols (9): | |||||||||
| 2,3-butanediol | 5.76 | 45 | 7 | 0.42 ± 0.08 | 0.41 ± 0.11 | 0.50 ± 0.18 | 0.43 ± 0.09 | 0.32 ± 0.07 | 0.39 ± 0.10 |
| 1,2,3-Benzenetriol | 13.40 | 126 | 5 | 0.15 ± 0.02 | 0.21 ± 0.04 | 0.73 ± 0.21 | 0.13 ± 0.06 | 0.39 ± 0.11 | 0.22 ± 0.06 |
| 1,4-Benzenediol | 12.34 | 81 | 8 | 0.19 ± 0.05 | 0.17 ± 0.03 | 0.10 ± 0.01 | 0.13 ± 0.02 | ND | 0.17 ± 0.11 |
| 2-Methyl-1-butanol | 4.05 | 57 | 3 | 1.40 ± 0.45 | 1.78 ± 0.25 | 1.45 ± 0.11 | 0.73 ± 0.08 | 0.16 ± 0.04 | 0.99 ± 0.17 |
| 2-Phenylethanol | 8.81 | 107 | 4 | 4.10 ± 1.08 | 5.55 ± 1.16 | 4.38 ± 0.98 | 2.56 ± 0.45 | 1.81 ± 0.76 | 2.39 ± 0.54 |
| Benzyl alcohol | 8.45 | 79 | 5 | 0.18 ± 0.06 | 0.22 ± 0.04 | 0.13 ± 0.06 | 0.14 ± 0.03 | 0.22 ± 0.06 | 0.11 ± 0.02 |
| Isoamyl alcohol | 5.32 | 70 | 3 | 2.70 ± 0.76 | 5.67 ± 0.76 | 2.02 ± 0.32 | 1.01 ± 0.32 | 1.02 ± 0.06 | 2.26 ± 0.43 |
| Methionol | 7.79 | 106 | 9 | 0.04 ± 0.00 | 0.18 ± 0.04 | 0.02 ± 0.00 | ND | ND | ND |
| Tyrosol | 13.43 | 107 | 3 | 0.73 ± 0.16 | 0.43 ± 0.08 | 0.48 ± 0.09 | 0.53 ± 0.08 | 0.05 ± 0.00 | 0.26 ± 0.07 |
| Aldehydes and ketones (6): | |||||||||
| 1,3-Diacetoxypropane * | 7.75 | 61 | 8 | 0.41 ± 0.06 | 0.16 ± 0.03 | 0.19 ± 0.04 | 0.06 ± 0.00 | 0.51 ± 0.12 | 0.07 ± 0.00 |
| 4,4-Diethyl-3-methylene-2-oxetanone | 15.09 | 14 | 25 | 0.08 ± 0.00 | 0.04 ± 0.00 | 0.10 ± 0.02 | 0.04 ± 0.00 | 0.15 ± 0.04 | 0.08 ± 0.01 |
| 3-Methyl-1,2-cyclopentanedione | 8.21 | 112 | 13 | 0.02 ± 0.00 | ND | 0.02 ± 0.00 | 0.05 ± 0.00 | ND | 0.02 ± 0.00 |
| 5-Hydrxoymethylfurfural | 11.34 | 97 | 10 | 0.46 ± 0.12 | 0.34 ± 0.04 | 0.43 ± 0.08 | 0.23 ± 0.04 | 4.15 ± 0.78 | 0.41 ± 0.23 |
| 5-Methyl furfural | 7.41 | 110 | 5 | 0.16 ± 0.03 | 0.18 ± 0.02 | 0.24 ± 0.08 | 0.01 ± 0.00 | 0.06 ± 0.00 | 0.14 ± 0.03 |
| Acetoin | 7.17 | 43 | 0.26 ± 0.06 | 0.14 ± 0.04 | 0.15 ± 0.02 | 0.22 ± 0.06 | 0.36 ± 0.10 | 0.16 ± 0.02 | |
| Butyrolactone | 4.65 | 42 | 6 | 0.03 ± 0.00 | 0.04 ± 0.00 | 0.03 ± 0.00 | 0.03 ± 0.00 | 0.01 ± 0.00 | 0.01 ± 0.00 |
| Others (6): | |||||||||
| 2-Acetyl-1-pyrroline * | 8.87 | 66 | 12 | ND | ND | ND | 0.01 ± 0.00 | 0.05 ± 0.01 | 0.03 ± 0.00 |
| 4-Anisidine * | 8.37 | 45 | 4 | ND | ND | ND | ND | 0.21 ± 0.05 | 0.18 ± 0.04 |
| 2-Methylpyrazine * | 4.96 | 94 | 2 | ND | ND | ND | 0.08 ± 0.01 | 0.01 ± 0.00 | 0.05 ± 0.00 |
| Acetin * | 10.00 | 43 | 8 | ND | ND | 0.03 ± 0.00 | 0.12 ± 0.03 | 0.22 ± 0.06 | ND |
| Coumaran | 10.97 | 120 | 4 | 0.89 | 0.64 ± 0.11 | 0.81 ± 0.16 | 0.68 ± 0.09 | 0.45 ± 0.05 | 0.90 ± 0.02 |
| N-acetyl tyramine | 13.85 | 107 | 10 | 0.18 ± 0.04 | 0.18 ± 0.07 | 0.13 ± 0.05 | 0.16 ± 0.02 | 0.03 ± 0.00 | 0.09 ± 0.02 |
* Represents the first detection of identification of these metabolites in balsamic vinegars. Volatile metabolites with p-value < 0.01 are shown in italics. RT = Retention time; Avg = Average; RSD = Residual Standard Deviation; ND = not detected, D = DelmaineTM, L = LupiTM, M1 = MazettiTM one leaf, M4 = MazettiTM four leaves, P = Pam’sTM and T = TastemakerTM.