Sustainable Valorization of the Brown Seaweed Bifurcaria bifurcata : Chemical Characterization and Bioactive Potential

Bifurcaria bifurcata R. Ross 1958 is a perennial brown seaweed belonging to the Sargassaceae family and represents an underexploited marine bioresource with promising applications in the sustainable food and pharmaceutical sectors. To support its sustainable valorization as an alternative to synthetic additives, this study provides a comprehensive evaluation of the chemical composition, bioactivity, and mineral profile of B. bifurcata to support its valorization. The essential oil, obtained by hydrodistillation and characterized by GC—MS, revealed a rich chemical profile comprising 51 compounds, of which 42 were identified, accounting for 95.37% of the total composition. The major constituents included 2′-hydroxy-4′,5′-dimethylacetophenone (13.11%), benzene, 1-ethyl-3,5-dimethyl- (9.79%), 1,5,9-cyclododecatriene, 1,5,9-trimethyl- (8.57%), and benzene, 1-(1,1-dimethylethyl)-4-methoxy- (8.52%). The essential oil exhibited moderate antioxidant activity under in vitro conditions, with a total antioxidant activity of 74.85 ± 2.78 mg E α-tocopherol/g and IC 50 values of 0.103 ± 0.004 (DPPH), 0.106 ± 0.002 (FRAP), and 2.672 ± 0.123 mg/mL (β-carotene bleaching assay). In addition, notable antibacterial activity was observed against Escherichia coli , Staphylococcus aureus , Bacillus subtilis , and Listeria monocytogenes , with inhibition zones ranging from 10 to 12 mm. Mineral analysis of the seaweed powder highlighted its nutritional importance, with high levels of organic matter, proteins, and sugars, along with substantial concentrations of essential macroelements (K, Ca, Mg, and Na) and trace elements (Fe, Mn, and Zn). Overall, these findings demonstrate the potential of B. bifurcata as a sustainable marine resource for the development of natural antioxidants, antimicrobial agents, and mineral-rich ingredients, contributing to environmentally friendly food systems and green pharmaceutical applications.