Effect of Extraction Conditions on the Antioxidant Activity of Olive Wood Extracts

Table 4

Extraction yields and radical scavenging percentages of several extracts prepared by the extraction procedures E3 and E4 from olive wood samples A, B, C, and D.

Olive wood sample^a	Extract^a	Procedure^b	Solvent	Yield^c	RSP ± SD^d
A	A4	E3	EtOAc	14.2	64.9 ± 0.1
B	B1	E3	EtOAc	46.8	63.7 ± 1.3
C	C1	E3	EtOAc	91.8	59.1 ± 2.6
D	D1	E3	EtOAc	14.2	40.5 ± 0.7
A	A11	E4	EtOH	94.3	52.4 ± 1.7
B	B2	E4	EtOH	117.3	38.3 ± 2.6
C	C2	E4	EtOH	172.5	42.4 ± 0.6
D	D2	E4	EtOH	81.7	42.9 ± 2.2
Rosemary oleoresin (reference extract)^e					95.0 ± 0.3

aExtracts were prepared from (a) the olive wood sample A, collected in April, 2003 (during the pruning period) at the village of Fuensanta, Jaén province, Spain; (b) the olive wood sample B, collected in March, 2005 (during the pruning period) at the same location of sample A; (c) the olive wood sample C, collected in March, 2005 (during the pruning period) at the village of Mogón, Jaén province, Spain; (d) the olive wood sample D, collected in November, 2006 (during the harvesting season) at the same location of sample A.
bProcedures E3 and E4 are detailed in Figures 3 and 4.
cYield is expressed as grams of extract per kilogram of olive wood sample.
dRadical scavenging percentage (RSP) is expressed as DPPH^• scavenging (%). Values are means of three replicates ± SD (standard deviation).
^eCommercially available rosemary extract was used as reference, at the same concentration (50 𝜇g mL⁻¹).