Abstract:
A study of extraction of essential oil (EO) from Tham-mang (Litsea petiolata) was conducted.
Different of plant parts in terms of fresh and dried leaves and stem was extracted. Dried plants were
done under hot air oven at 50c for 24 hr. and shade dry for 7 days. Extraction methods applied in
this study hydro-distillation, simultaneous distillation extraction (SDE), and extraction using solvent
such as ethanol, petroleum ether and diethyl ether. It was found that all thirty oil samples
from L. petiolata consisted of 11 volatile compounds and among which five compounds;
undec-1O-en-2-one, 2-undecanone, tridec-12-en-2-onc, undecanal and 2-tridecanone, were the major
components. Odor description of the five major compounds was citrus, fresh green, wood, spice and
sweet. The percent relative peak of five major compounds in oil extracted from oven-dried leaves
using hydro-distillation was highest at 48.9%, 21.0%, 10.2%, 6.1 %, and 2.5%, respectively.
However, oils extracted from oven-dried leaves by SDE also gave a greater relative peak area.
Although oils from oven-dried leaves extracted by SDE and hydro-distillation had the greatest yield
at 3.7% and 3.3% (w/w of dry weight), its total phenolic compounds was lowest at 0.76 mg gallic
acidlg extract. Results also showed that tannin contents from EOs by all extraction procedures were
relatively high at 11.36 - 36.27 mg catechinlg extract. When antioxidant activity was measured,
percent scavenging effect of EOs from oven dried leaves extracted by hydro-distillation was less
than EOs by other methods. Moreover, all thirty oil samples extracted from L. petiolata were tested
for their antibacterial against Leuconostoc mesenteroides and Escherichia coli by disc diffusion agar
method. Results indicated that EOs extracted from oven-dried leaves by all extraction method,
except from petroleum extract could inhibit the growth of L. mesenteroides which clear zone of 6.00
- 10.00 mm. was observed. EOs extracted from oven-dried leave using hydro-distillation shows the
highest efficiency in inhibition the growth of E. coli with clear zone of 6.00 - 7.87 mm. was
detected.
Sensory analysis of EOs from leaves and stems (fresh, oven-dry and shade-dry) and L. petiolata
extracted by hydro-distillation were evaluated and compared with synthetic compound and giant
water bug. It was found that the odor of EOs did not differ from the natural and synthetic ones. EOs
extracted from oven-dried leaves by hydro-distillation was added in chilli paste (numprick) for
replacing the usage of natural giant water bug. Panelists preferred the sample added EOs at
concentration less than 0.5% due to the taste was not bitter and pungent and the odor was strong.
Overall acceptance of this sample did not differ from that chilli paste with giant water bug. Addition
of extraction EOs from oven-dried leaves by hydro-distillation was possible at the minimum
concentration of 0.14% whose sensory scores for taste, chilli paste odor, giant water bug odor and
overall acceptance did not differ from those added natural giant water bug.