pressure to ambient. The duration of the extraction was 2 h. Pandan
leaf extracts were collected in collector (11) and (12). Less volatile
extracts were deposited in collector (11) but high volatile components
were passing through it and enter the collector (12). In
order to ensure a good degree of contact between the gas and liquid
phases, a minimum 20 ml of acetone was necessarily used as
absorbent. Collector (12) was pre-charged with this volume of acetone
and was immersed in a cooling bath (13) containing a dry
ice-acetone mixture at −82 ◦C. CO2 stream was bubbled through
the pre-charged acetone and the very volatile components were
absorbed by acetone in this collector. Extracts collected in collector
(11) was washed out by acetone and added together with
those obtained from collector (12), so a whole extracts solution
was obtained.
The acetone was then removed from the extracts using rotaryevaporator
(Rotavapor-RE, Buchi Orme Scientific Ltd., England)
under a reduced pressure, at bath temperature of 40 ◦C for up to
10 min until solvent free extracts were obtained. The extracts were
diluted with 10 mlof acetone and transferred to screw-capped glass
vials and then were stored in refrigerator at 4 ◦C for further analysis.
All the experiments were carried out in triplicates.
2.5.2. Hexane extraction procedure
Organic solvent extraction was carried out in Soxhlet apparatus
using hexane as solvent. Five grams of Pandan leaves (wet weight)
were packed into a cellulose thimble, which was then transferred
into the Soxhlet extractor. Approximately, 300 ml of hexane were
used in a typical run. The temperature was 68 ◦C and the total reflux
time was up to 4 h. After cooling for 1 h, the solvent was evaporated
using rotary evaporator under reduced pressure, at 40 ◦C bath temperature
for up to 2 h. The extracts were then diluted in 10 ml of
acetone until used. All Soxhlet extractions were done in triplicates