Table 2.
Summative chemical composition (% of total dry weight) of untreated and residual solid fraction of pretreated bark samples.
| Untreated | HT | SE | OS/SE | OS 50:50 | OS 80:20 | OS/NaOH | |
|---|---|---|---|---|---|---|---|
| total sugars | 4.45 | 5.38 | 5.61 | 6.11 | 6.19 | 7.58 | 7.75 |
| glucose | 2.19 | 4.35 | 4.43 | 5.37 | 4.26 | 4.86 | 5.82 |
| xylose | 0.67 | 0.58 | 0.80 | 0.53 | 1.28 | 0.75 | 0.61 |
| galactose | 0.21 | 0.06 | 0.03 | n.d. | n.d. | n.d. | n.d. |
| arabinose | 1.21 | 0.35 | 0.28 | 0.10 | 0.63 | 0.11 | 0.18 |
| mannose | 0.18 | 0.04 | 0.07 | 0.11 | 0.02 | n.d. | 0.01 |
| ash | 0.67 | 0.41 | 0.26 | 0.19 | 0.19 | 0.23 | 0.21 |
| total extractives | 39.39 | 27.98 | 31.58 | 30.19 | 29.23 | 22.32 | 19.27 |
| dichloromethane | 25.49 | 24.57 | 26.99 | 25.65 | 23.76 | 16.18 | 16.56 |
| ethanol | 9.96 | 2.67 | 1.82 | 2.69 | 1.18 | 3.89 | 1.21 |
| water | 3.94 | 0.74 | 2.77 | 1.85 | 4.29 | 2.25 | 0.5 |
| suberin | 44.06 | 40.47 | 38.33 | 35.16 | 42.01 | 34.52 | 29.94 |
| lignin | 9.11 | 20.97 | 19.84 | 20.93 | 16.36 | 25.57 | 26.5 |
| klason | 8.87 | 20.80 | 19.59 | 20.65 | 16.18 | 25.36 | 26.2 |
| acid-soluble | 0.24 | 0.17 | 0.25 | 0.27 | 0.18 | 0.21 | 0.3 |
| suberin + lignin | 53.17 | 61.44 | 58.17 | 56.09 | 58.37 | 60.09 | 56.44 |
| total | 97.68 | 95.21 | 95.62 | 92.58 | 93.98 | 90.22 | 83.67 |
n.d. Not detected.