Abstract

Suaeda salsa is a genus of Salicaria in the Chenopodiaceae family. S. salsa is mainly distributed in coastal areas, growing in saline-alkali soil. Flavonoids are found in Salicyphala salicyphala and have various functions, such as lowering blood glucose, resisting mutagenesis and improving immunity. It was found that flavonoids also had antioxidant effects, and the study of antioxidant activity of flavonoids became the focus. In this paper, the flavonoids were extracted from the halophytic plant S. salsa by 60% ethanol extraction method, and the antioxidant activity was compared with ascorbic acid (VC) solution. To optimize the ethanol extraction process of flavonoids from S. salsa, factors of extraction time, extraction temperature, and liquid-solid ratio on the mass of flavonoids derived from S. salsa were investigated to seek the optimal extraction conditions. The results showed that the optimal extraction conditions were as follows: extraction time 58.63 min, extraction temperature 52.08°C, solid-liquid ratio 1:21.33 g/mL. Under these conditions, the extraction mass of flavonoids reached 6.40 mg/g. When the concentration of flavonoids was 1.5 g/L, the hydroxyl radical removal rate reached the maximum (54.94%). At the same time, the extraction process of flavonoids from Suaeda salicata optimized by response surface analysis is also reasonable and feasible.

Key words: Suaeda salsa, flavonoids, response surface methodology, optimization.