As pre-extracted fraction contains phenolic, and also fucoidan has been previously shown to have antioxidant activity, both pre-extracted fraction and fucoidan were tested for antioxidant activities.
Fig. 2 shows that pre-extracted fraction exhibits strong antioxidant activities.
At 10 mg/mL, the DPPH free radical scavenging effect and reducing power absorbance were 79% and 2.19, respectively.
Ye et al. tested antioxidant activities of ethanol extract from brown seaweed Sargassum pallidum, the polyphenol content standardized against chlorogenic acid was 5.34% in theextract (Ye et al., 2009).
The DPPH scavenging effect was 11.55% at 2 mg/mL, while for our work, it is 26% at the same concentration.
The reducing power absorbance for Ye et al.’s extract was 0.267 at 0.2 mg/mL, while it is 0.67 at 1 mg/mL in our work, indicating that our system leads to enhanced antioxidant behavior