Table 3: Extraction yields and radical scavenging percentages of several extracts prepared by the extraction procedure E7 from the olive wood sample A.

ExtractaPretreatmentbTimecReextracted materialdYieldeRSP ± SDf

A21H2SO4 in H2O1 hAcidic extract29.249.7 ± 0.6
A22H2SO4 in H2O1 hPre-treated wood8.837.4 ± 0.1
A23H2SO4 in H2O3 hAcidic extract23.649.6 ± 0.8
A24H2SO4 in H2O3 hPre-treated wood4.759.6 ± 0.4
A25H2SO4 in H2O5 hAcidic extract34.849.2 ± 0.9
A26H2SO4 in H2O5 hPre-treated wood5.559.6 ± 1.6

A27H2SO4 in H2O : EtOH1 hAcidic extract25.754.0 ± 1.3
A28H2SO4 in H2O : EtOH1 hPre-treated wood5.229.9 ± 1.9
A29H2SO4 in H2O : EtOH3 hAcidic extract71.248.1 ± 2.9
A30H2SO4 in H2O : EtOH3 hPre-treated wood5.938.4 ± 1.7
A31H2SO4 in H2O : EtOH5 hAcidic extract74.545.7 ± 1.2
A32H2SO4 in H2O : EtOH5 hPre-treated wood2.363.1 ± 0.6

A33HCl in H2O1 hAcidic extract27.556.6 ± 0.5
A34HCl in H2O1 hPre-treated wood4.938.1 ± 0.9
A35HCl in H2O3 hAcidic extract26.458.5 ± 2.1
A36HCl in H2O3 hPre-treated wood6.168.7 ± 1.1
A37HCl in H2O5 hAcidic extract23.548.8 ± 0.4
A38HCl in H2O5 hPre-treated wood9.064.5 ± 0.4

A39HCl in H2O : EtOH1 hAcidic extract40.043.0 ± 1.2
A40HCl in H2O : EtOH1 hPre-treated wood7.553.8 ± 0.3
A41HCl in H2O : EtOH3 hAcidic extract58.541.6 ± 0.8
A42HCl in H2O : EtOH3 hPre-treated wood7.156.4 ± 1.8
A43HCl in H2O : EtOH5 hAcidic extract94.145.9 ± 2.4
A44HCl in H2O : EtOH5 hPre-treated wood3.660.9 ± 1.9

Rosemary oleoresin (reference extract)g95.0 ± 0.3

Extracts A21–A44 were prepared from the olive wood sample A, collected in April, 2003 (during the pruning period) at the village of Fuensanta, Jaén province, Spain.
The olive wood sample A was subjected to a hydrolysis pre-treatment with 0.5 M H2SO4 in H2O (extracts A21–A26), 0.5 M H2SO4 in H2O : EtOH (50 : 50, v/v) (extracts A27–A32), 1 M HCl in H2O (extracts A33–A38), and 1 M HCl in H2O : EtOH (50 : 50, v/v) (extracts A39–A44) (see Figure 7).
Time of the hydrolysis pre-treatment on the olive wood sample A at 130°C.
The hydrolysis pre-treatment of olive wood sample A afforded a liquid acidic extract and a solid pre-treated wood on which further extractions were performed (see Figure 7).
Yield is expressed as grams of extract per kilogram of olive wood sample.
Radical scavenging percentage (RSP) is expressed as DPPH scavenging (%). Values are means of three replicates ± SD (standard deviation).
Commercially available rosemary extract was used as reference, at the same concentration (50  g mL−1).