Table 1.
Classification of the main hydrophilic phenolic compounds found in virgin olive oils and their average concentration in different types of olive oil.
| Chemical Structure | Components | ROO mg/kg * (Mean ± SD) | Virgin (Fine) mg/kg * (Mean ± SD) | EVOO mg/kg * (Mean ± SD) |
|---|---|---|---|---|
| Phenolic acids | benzoic | - | - | - |
| gallic | - | - | - | |
| p-hydroxybenzoic | - | 0.37 ± 0.37 | - | |
| protocatechuic | - | 1.47 ± 0.56 | - | |
| syringic | - | 0.81 ± 1.17 | 0.25 ± 0.25 | |
| vanillic | - | 1.22 ± 2.04 | 0.64 ± 0.50 | |
| caffeic | - | 0.21 ± 0.63 | 0.19 ± 0.45 | |
| cinnamic | - | - | 0.17 ± 0.14 | |
| o-coumaric | - | - | - | |
| p-coumaric | - | 0.24 ± 0.81 | 0.92 ± 1.03 | |
| ferulic | - | 0.19 ± 0.50 | 0.19 ± 0.19 | |
| sinapic | - | - | - | |
| Phenolic alcohols | hydroxytyrosol (3,4-DHPEA) | 6.77 ± 8.26 | 3.53 ± 10.19 | 7.7 2 ± 8.81 |
| tyrosol (p-HPEA) | 4.11 ± 2.24 | 5.34 ± 6.98 | 11.32 ± 8.53 | |
| Secoiridoids | oleuropein | - | - | 1.65 ± 1.85 |
| oleuropein aglycone | 125.40 ± 41.80 | 120.57 ± 125.53 | 36.63 ± 24.34 | |
| ligstroside aglycone | 59.93 ± 18.58 | 82.01 ± 67.78 | 17.44 ± 18.13 | |
| monoaldehydic form of oleuropein aglycone (3,4-DHPEA-EA) | 10.90 ± 0.00 | 95.00 ± 116.01 | 72.20 ± 64.00 | |
| monoaldehydic form of ligstroside aglycone (p-HPEA-EA) | 15.20 ± 0.00 | 69.05 ± 69.00 | 38.04 ± 17.23 | |
| dialdehydic form of decarboxymethyl elenolic acid linked to hydroxytyrosol (oleacein: 3,4-DHPEA-EDA) | 57.37 ± 27.04 | 77.83 ± 256.09 | 251.60 ± 263.24 | |
| dialdehydic form of decarboxymethyl elenolic acid linked to tyrosol (oleocanthal: p-HPEA-EDA) | 38.95 ± 9.29 | 71.47 ± 61.85 | 142.77 ± 73.17 | |
| Flavonoids | flavones | |||
| luteolin | 1.17 ± 0.72 | 1.29 ± 1.93 | 3.60 ± 2.32 | |
| apigenin | 0.30 ± 0.17 | 0.97 ± 0.71 | 11.68 ± 12.78 | |
| flavanonol | ||||
| taxifolin | - | - | - | |
| Lignans | (+)-1-acetoxypinoresinol | 7.52 ± 9.10 | 4.43 ± 21.28 | 6.63 ± 10.78 |
| (+)-pinoresinol | 24.05 ± 10.02 | 23.71 ± 17.03 | 4.19 ± 2.78 | |
| Hydroxy-isocromans | 1-phenyl-6,7-dihydroxy-isochroman | - | - | - |
| 1-(3′-methoxy-4′hydroxy)-6,7-dihydroxy-isochroman | - | - | - | |
| Polyphenols, total | 198.0 ± 14.85 | 206.73 ± 150.08 | 551.42 ± 235.02 |