Affiliation:
1. School of Environmental and Life Sciences, Faculty of Science, The University of Newcastle, Ourimbah NSW 2258, Australia
Abstract
Background:
Lemon myrtle (Backhousia citriodora), is native to Australia and has a significant
value as an aromatic herb and folk medicine. Recently, it has shown potential applications
in the food, pharmaceutical, and cosmetic industries.
Objective:
This study was designed to identify the most suitable safe solvent for the extraction of
phenolic compounds and antioxidant properties from lemon myrtle leaves and then apply response
surface methodology (RSM) to develop the optimal conditions (time, temperature, and sonication
power) for the extraction of phenolic compounds and antioxidant properties from lemon myrtle using
ultrasonic-assisted extraction (UAE).
Methods:
Five different solvents viz water, acetone, ethanol, acetone: water (50:50), and ethanol:
water (50:50) were tested for extraction efficiency of phenolic compounds and antioxidant properties
from dried lemon myrtle leaves. A three-level three-factor Box-Behnken design was employed
to elucidate the effect of sonication time, extraction temperature, and sonication power on the
yields of total phenolics, antioxidant capacities, and major individual compounds (gallic acid and
hesperetin).
Results:
The results showed that solvents have a significant impact on the extraction efficiency of
bioactive compounds and antioxidant properties from lemon myrtle, and 50% acetone is the best
solvent. Mathematical models were reliable for the prediction of optimal extraction conditions and
the optimal conditions for the extraction of phenolic compounds and antioxidant capacity, as well
as gallic acid and hesperetin are 50 min, 60°C and sonication power of 250 W.
Conclusion:
These optimal conditions and 50% acetone in water (as solvent) are recommended to
extract phenolic compounds and antioxidant capacity from lemon myrtle leaves as a functional
food ingredient.
Publisher
Bentham Science Publishers Ltd.