Levels (μg/g dw) of PCs quantified in cane and bunch stem by-products
| Phenolic compound | Cane | Bunch stem |
|---|---|---|
| Hydroxybenzoic acids | ||
| Gallic acid | 30 ± 1 | 33 ± 1 |
| Syringic acid | n.d. | 154 ± 4 |
| Total | 30 ± 1 | 187 ± 5 |
| Hydroxycinnamic acids | ||
| Caftaric acid | 253 ± 7 | 2,283 ± 65 |
| Caffeic acid | 417 ± 8 | 331 ± 4 |
| Total | 669 ± 15 | 2,614 ± 69 |
| Stilbenes | ||
| trans-piceid | 533 ± 11 | 284 ± 3 |
| trans-piceatannol | 60 ± 2 | n.d. |
| trans-resveratrol | 69 ± 1 | n.d. |
| ε-viniferin | 1,041 ± 33 | 89 ± 1 |
| Pteroestilbene | 161 ± 5 | 168 ± 4 |
| Total | 1,864 ± 52 | 541 ± 8 |
| Flavanols | ||
| Procyanidin B1 | 72 ± 1 | 1,015 ± 32 |
| (+)-catechin | 541 ± 9 | 2,421 ± 90 |
| Procyanidin B2 | 53 ± 1 | 70 ± 2 |
| (–)-epicatechin | 175 ± 6 | 49 ± 1 |
| (–)-epigallocatechin gallate | 110 ± 1 | 248 ± 12 |
| (–)-gallocatechin gallate | 88 ± 1 | 105 ± 1 |
| Total | 1,040 ± 19 | 3,907 ± 138 |
| Flavanones | ||
| Astilbin | n.d. | 1,391 ± 22 |
| Naringenin | 72 ± 3 | n.d. |
| Total | 72 ± 3 | 11,391 ± 22 |
| Flavonols | ||
| Quercetin 3-β-D galactoside | 7 ± 0.2 | 30 ± 1 |
| Quercetin 3-β-D-glucosidoe | n.d. | 11 ± 0.1 |
| Kaempferol-3-glucoside | n.d. | 31 ± 1 |
| Myricetin | n.d. | 93 ± 4 |
| Total | 7 ± 0.2 | 164 ± 6 |
| Other compounds | ||
| OH-tyrosol | n.d. | 348 ± 8 |
| Tyrosol | n.d. | 12 ± 0.6 |
| total | n.d. | 360 ± 9 |
| Total PC | 3,682 ± 90 | 9,163 ± 257 |
n.d.: not detected. PCs: phenolic compounds. Results are expressed as the mean ± standard deviation (SD) (n = 3 replicates)