Comparative Analysis of Biological Activities and Phenolic Content between Fresh and Steamed Sargassum fusiforme in Different Extraction Solvents

Sargassum fusiforme (SF), a perennial brown, is often steamed for consumption. SF contains many bioactive compounds; however, the effect of steaming these compounds is unknown. This study investigates phenolic component contents and antioxidant and antiaging activities of fresh (SF) and steamed (SSF) extracts in different solvents (95% ethanol, 95% methanol, hot water). Total polyphenol and flavonoid content was highest in SSF methanol (9.76 mg TAN/g) and SF methanol extracts (13.42 mg QUE/g). The DPPH radical scavenging activity was highest in SF methanol extracts (IC50 = 5.83 μg/μL), whereas the FRAP activity was higher in SSF extracts. Methanol SSF extract exhibited higher SOD, CAT, and APX activities. Collagenase inhibition activity was higher in all SSF extracts, whilst tyrosinase inhibition activity was highest in SSF methanol extract (30.5%). Analysis of phenolic compound contents revealed that 4-hydroxybenzoic acid content was highest in SF methanol extract, whilst steaming increased naringenin and naringin contents in ethanol extracts. Finally, antioxidant activity of both extracts showed a positive correlation with polyphenol content. Overall, these results suggested that SSF ethanol and methanol extract had higher phenolic component content and antioxidant and antiaging activities. Thus, SSF can be potentially used in health functional foods and cosmetic products.