Abstract
Dictyotales, a common taxonomic group of brown seaweeds found in warm and temperate waters, are known for their richness in bioactive metabolites. In this study, six species of Dictyotales (Dictyopteris polypodioides, Dictyota dichotoma, Dictyota fasciola, Dictyota spiralis, Padina pavonica, and Taonia atomaria) collected from the Tunisian coasts were investigated for their antioxidant potentials, based on their contents of high added-value bioactive metabolites such as fucoxanthin and polyphenols. Fucoxanthin and polyphenols were analyzed quantitatively by high-performance liquid chromatography (HPLC) and UV spectrophotometer, respectively. The antioxidant property of extracts was also determined based on their ability to scavenge 2,2-Diphenyl-1-picrylhydrazyl (DPPH’s) free radical. Thus, the highest concentrations of fucoxanthin were obtained from T. atomaria and D. polypodioides (5.53 ± 1.2 and 3.43 ± 1.3 mg⋅g–1 dry weight, respectively), while the lowest amount was from D. spiralis (0.23 ± 0.1 m mg⋅g–1 dry weight). Dictyota dichotoma and T. atomaria gave the highest total phenol content (19.3 ± 0.4 and 15.2 ± 1.1 mg GAE⋅g–1 dry weight, respectively). In the second step, supercritical carbon dioxide (ScCO2) was used as a green and environmentally safe technique for the extraction of fucoxanthin from the most abundant species D. polypodioides. The extraction of fucoxanthin by ScCO2 allowed an extraction yield ranging from 0.50 ± 0.04% to 1.32 ± 0.02%, with 60°C temperature and 50-MPa pressure as the best extraction conditions. The maximum fucoxanthin and polyphenol recovery in the extract attained 15 and 64%, respectively. The results strengthen the possible use of Dictyotales from the Mediterranean Sea as a promising source of natural ingredients of health and economic interests contributing to Blue Growth in the region.
Highlights
Seaweeds are one of the main components of marine ecosystems; being primary producers in the food chain, they play a key ecological role in coastal ecosystems and are a key element of the Blue Economy
D. polypodioides displayed the highest and significantly different (p
The lowest FC was obtained for D. spiralis with 0.23 ± 0.1 mg·g−1 dw, while values obtained for D. fasciola (0.88 ± 0.3 mg·g−1 dw) and P. pavonica (0.71 ± 0.1 mg·g−1 dw) were not significantly different
Summary
Seaweeds are one of the main components of marine ecosystems; being primary producers in the food chain, they play a key ecological role in coastal ecosystems and are a key element of the Blue Economy. In Fucoxanthin and Phenolic Contents of Dictyotales order to preserve their survival, algae developed various defense mechanisms including the production of secondary metabolites with biological properties (Da Gama et al, 2002; Ganesan et al, 2019). Such metabolites represented by a large number of potent antioxidant compounds including carotenoids, phlorotannins, and sulfated polysaccharides make algae valuable sources for exploitation (Corsetto et al, 2020). Among these compounds, fucoxanthin, a natural carotenoid pigment, is commonly distributed in brown algae and diatoms.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
