Abstract:

The aim of the current study was to optimize the extraction conditions for total flavonoids from sea buckthorn
(Hippopphae rhamnoides L.) pomace (the leftover residue from juice making) by orthogonal array design. The antioxidant
activity of the total flavonoids extracted was assessed by hydroxyl radical and superoxide anion radical scavenging,
and reducing power assays, respectively. Ethanol concentration, extraction time and the ratio of material to solvent
were identified as three main variables that affect extraction efficiency by signal factor experiments, and these factors
were further optimized to be 60%, 40 min and 1:50 (g/mL), respectively, using orthogonal array design. Under the
optimized conditions, the predicted extraction yield of total flavonoids from sea buekthom pomace was 2.55%. The
total flavonoids had strong reducing power, and exhibited a more powerful scavenging effect against superoxide anion
radical than against hydroxyl radical.

Key words: sea buckthorn pomace, flavonoids, extraction process, antioxidation