Levels (μg/g dw) of PCs quantified in cane and bunch stem by-products

Phenolic compoundCaneBunch stem
Hydroxybenzoic acids
Gallic acid30 ± 133 ± 1
Syringic acid n.d.154 ± 4
Total30 ± 1187 ± 5
Hydroxycinnamic acids
Caftaric acid 253 ± 72,283 ± 65
Caffeic acid 417 ± 8331 ± 4
Total669 ± 152,614 ± 69
Stilbenes
trans-piceid533 ± 11284 ± 3
trans-piceatannol60 ± 2n.d.
trans-resveratrol69 ± 1n.d.
ε-viniferin1,041 ± 3389 ± 1
Pteroestilbene161 ± 5168 ± 4
Total1,864 ± 52541 ± 8
Flavanols
Procyanidin B172 ± 11,015 ± 32
(+)-catechin 541 ± 92,421 ± 90
Procyanidin B2 53 ± 170 ± 2
(–)-epicatechin 175 ± 649 ± 1
(–)-epigallocatechin gallate 110 ± 1248 ± 12
(–)-gallocatechin gallate88 ± 1105 ± 1
Total1,040 ± 193,907 ± 138
Flavanones
Astilbinn.d.1,391 ± 22
Naringenin72 ± 3n.d.
Total72 ± 311,391 ± 22
Flavonols
Quercetin 3-β-D galactoside7 ± 0.230 ± 1
Quercetin 3-β-D-glucosidoen.d.11 ± 0.1
Kaempferol-3-glucosiden.d.31 ± 1
Myricetinn.d.93 ± 4
Total7 ± 0.2164 ± 6
Other compounds
OH-tyrosoln.d.348 ± 8
Tyrosoln.d.12 ± 0.6
totaln.d.360 ± 9
Total PC3,682 ± 909,163 ± 257

n.d.: not detected. PCs: phenolic compounds. Results are expressed as the mean ± standard deviation (SD) (n = 3 replicates)