Ultrasonic extraction
of total phenolics, total flavonoids,
and antioxidant activities
from Gymnema sylvestre
Authors: Nguyen Tan Thanh, Nguyen Thi Uyen Nhi, Dinh Thi Truong Giang, Truong Chien Thang, Bui Xuan Hung
Vietnam Journal of science and technology, seri B
: 1/65 : 6-11
Publishing year: 1/2023
The study on ultrasonic extraction conditions aims to
improve the yield of total phenolic content, total flavonoid
content, and antioxidant activity from the leaves
of Gymnema sylvestre by response surface methodology
(RSM). The experimental arrangement according to the
Box - Benhken method, the optimal extraction conditions
were established for total phenolic content (Y1, %),
total flavonoid content (Y2, %), and antioxidant activity
(Y3, %), with four factors, are extraction temperature
(X1) ultrasonic time (X2) concentration of ethanol solvent
(X3), and ultrasonic power (X4). According to the model,
the optimal conditions for ultrasonic extraction to obtain
the highest content of biologically active compounds
are extraction temperature of 62oC, ultrasonic time
of 50 minutes, solvent concentration of 55%, and
ultrasonic power is 300 W. Under this condition, the
total phenolic content was 21.2±0.5 mg GAE/g, the total
flavonoid content was 8.2±0.15 mg CE/g, and the highest
antioxidant activity was 72.5±0.5%.
antioxidant activity, flavonoid, Gymnema sylvestre, phenolic, response surface methodology, ultrasonic extraction.
