Optimization of Ultrasonic-Assisted Extraction of Antioxidant
Compounds in Black Shallots (Allium ascalonicum) from Vietnam
using Response Surface Methodology
Authors: Tran Phuong Chi1, Bui Thi Trang2, Nguyen Thi Nu Trinh2, Le Thi Cam Tho2, Nguyen Tan Thanh1, Tran Dinh Thang2, Hoang Thi Le Hang3, Le Dang Quang4, Nguyen Ngoc Tuan2
Malaysian Journal of Chemistry
: Vol. 24(1), 1-10 : 26-35
Publishing year: 2/2022
Response surface methodology (RSM) was used to optimize the extraction conditions for total
phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity (DPPH) in black
shallots (Allium ascalonicum) using ultrasonic-assisted extraction (UAE). The variables used in the
process were extraction temperature (40-60oC), extraction time (60–80 min), ethanol concentration
(30–70%) and power level (60–100%/600W). The results indicated that extraction temperature,
extraction time, ethanol concentration and ultrasonic power level had an impact on TPC, TFC and
DPPH radical scavenging activity. The optimum extraction conditions obtained from RSM were:
extraction temperature of 53
oC, extraction time of 72 min, ethanol concentration of 48 % and
ultrasonic power level of 84 %. The experimental values of TPC, TFC and DPPH radical scavenging
activity were 17.28 ± 0.12 mg GAE/g, 5.42 ± 0.08 mg QE/g and 75.35 ± 0.15%, respectively
Key words: Allium ascalonicum; black shallot; total phenolic content (TPC); total flavonoid content (TFC); DPPH radical scavenging activity
