Topical Area: Dietary Bioactive Components
Objectives : It has been a long time since seaweeds have been used for food ingredients in Asian countries. Recently, a body of research has revealed the health benefits of bioactive compounds in seaweeds, especially their antioxidant capacities. Although numerous seaweeds inhabit in the ocean, only a small percentage has been explored for functional food. Therefore, the purpose of this study was to analyze the antioxidant capacities of various seaweeds grown off the Korean coast to screen for the potential functional food sources.
Methods : Ten ethanol extracts of Korean seaweeds were provided by the National Marine Biodiversity Institute of Korea, which included Scytosiphon gracilis, Scytosiphon lomentaria, Sargassum muticum, Sargassum confusum, Petrospongium rugosum, Sargassum fusiforme, Petalonia fascia, Sargassum nigrifolium, Ishige foliacea, and Myelophycus simplex. Hundred mg/L of samples in 80 % methanol was used to measure their ABTS, DPPH, and superoxide radical scavenging activities. Mg vitamin C equivalent antioxidant capacity (VCEAC)/100 mg was used to express the ABTS and DPPH radical scavenging capacities. For the superoxide radical scavenging capacity, inhibition rate of superoxide radical generation (%) was calculated.
Results : Among the ten seaweeds, S. nigrifolium and I. foliacea exhibited the most significant radical scavenging capacities. DPPH radical scavenging capacities of I. foliacea and S. nigrifolium were 122.4 mg VCEAC/100 mg and 95.8 mg VCEAC/100 mg, respectively. For ABTS radical scavenging capacity, I. foliacea exhibited 178.5 mg VCEAC/100 mg, followed by S. nigrifolium as 80.9 mg VCEAC/100 mg. I. foliacea inhibited about 68 % of superoxide radical generation followed by S. nigrifolium (40.6 %) while vitamin C as positive control inhibited about 28.9 % of superoxide radical generation. The antioxidant capacities measured by the three assays were positively correlated with each other.
Conclusions : The current study explored total antioxidant capacities of various Korean seaweeds and found I. foliacea and S. nigrifolium as the most potential antioxidant-rich food resources. Further research would be warranted to investigate bioactive compounds from S. nigrifolium and I. foliacea.
Funding Sources :
This work was supported by the Pukyong National University Research Fund in 2018.