Abstract:

In the present study, the impacts of SDS concentration, material-to-liquid ratio, microwave power, and irradiation
time on the extraction of total flavonoids from the fruits of fingered citron (Citrus medica var. sarcodactylis) were explored
by single factor and orthogonal array designs. Results indicated that the optimal extraction conditions were determined as
follows: SDS concentration, 0.6%; material-to-liquid ratio, 1:20 (g/mL); microwave power, 50 W; and irradiation time, 30 s.
The yield of total flavonoids under the optimized conditions was 18.706 0 mg/g. The total flavonoids scavenged 79.15% of
DPPH radical and 65.25% of ABTS radical, showing a slightly weaker radical scavenging activity than quercetin. Therefore,
the total flavonoids from fingered citron have potent antioxidant activity and can be used as antioxidants in the food and
medicine fields.

Key words: total flavonoids from fingered citron, SDS, microwave extraction, antioxidant activity