Table 1.
Phytochemical composition of coffee husk, coffee silverskin, and cocoa shell aqueous extracts characterized by UPLC–ESI–MS/MS. Values are expressed as mean ± SD (n = 3). Different letters among rows indicate significant differences (p < 0.05) according to ANOVA and Tukey’s multiple range test.
| Compound | Concentration (µg/g Extract) | Chemical Structure | ||
|---|---|---|---|---|
| Coffee Husk | Coffee Silverskin | Cocoa Shell | ||
| Hydroxybenzoic acids |
|
|||
| Gallic acid | 87.0 ± 5.5c | 16.9 ± 1.2a | 19.2 ± 0.4b | |
| Protocatechuic acid | 488.4 ± 26.2b | 44.1 ± 3.4a | 761.5 ± 47.6c |
|
| 4-hydroxybenzoic acid | 13.4 ± 1.3b | 3.4 ± 0.3a | 70.1 ± 9.3c |
|
| Vanillic acid | 22.90 ± 9.62a | 29.6 ± 0.6a | N.D. |
|
| Salicylic acid | 3.1 ± 0.1b | 2.3 ± 0.2a | 3.3 ± 0.2b |
|
| Hydroxycinnamic acids |
|
|||
| Caffeic acid | 57.9 ± 2.0b | 538.0 ± 54.3c | 1.9 ± 0.2a | |
| Chlorogenic acid | 3456.8 ± 70.6b | 2791.7 ± 97.3a | N.D. |
|
| p-coumaric acid | 8.7 ± 0.2c | 0.9 ± 0.1a | 4.2 ± 0.6b |
|
| Ferulic acid | N.D. | 3.8 ± 0.2 | N.D. |
|
| Mandelic acids |
|
|||
| 3-hydroxymandelic acid | N.D. | 4.4 ± 0.5 | N.D. | |
| Mandelic acid | N.D. | 5.1 ± 0.2a | 11.18 ± 1.2b |
|
| Phenylacetic acids |
|
|||
| 3,4-dihydroxyphenylacetic acid | 5.6 ± 2.0a | N.D. | 25.9 ± 2.4b | |
| 4-hydroxyphenylacetic acid | N.D. | N.D. | 48.5 ± 4.3 |
|
| Flavan-3-ols: monomers |
|
|||
| (+)-catechin | 1.7 ± 0.2a | 10.2 ± 1.1b | 200.8 ± 16.0c | |
| (−)-epicatechin | 18.0 ± 2.0a | N.D. | 222.1 ± 13.8b |
|
| Flavan-3-ols: dimers |
|
|||
| Procyanidin B1 | 22.3 ± 2.6a | N.D. | 83.6 ± 7.8b | |
| Procyanidin B2 | 11.6 ± 1.8a | N.D. | 219.9 ± 11.4b |
|
| Flavonols |
|
|||
| Quercetin-3-O-galactoside | 54.7 ± 0.5b | N.D. | 9.3 ± 0.4a | |
| Quercetin-3-O-glucoside | 57.4 ± 3.7b | N.D. | 11.12 ± 0.77a |
|
| Kaempferol-3-O-galactoside | 122.6 ± 3.6 | N.D. | N.D. |
|
| Alkaloids |
|
|||
| Caffeine | 9815.5 ± 15.4b | 19,219.2 ± 37.6c | 2433.5 ± 7.8a | |
| Theobromine | N.D. | N.D. | 10,035.0 ± 4.5 |
|
N.D. Non-detected.