Ultrasonic-Assisted Extraction of Fucoxanthin from Marine Macroalga Padina australis: Optimization, Bioactivity, and Structural Characterization

Macroalgae serve as a potential feedstock for fucoxanthin extraction. Fucoxanthin, a bioactive pigment found in the chloroplasts of marine algae, exhibits significant pharmacological properties. As a member of the carotenoid family, fucoxanthin plays a crucial role in both the food and pharmaceutical industries. This research explores the effects of ultrasonics on the extraction of fucoxanthin from the marine macroalga Padina australis. In addition, various extraction techniques and the influence of solvents on the efficient separation of fucoxanthin from algae have been studied and compared. Using methanol, chloroform, and a combination of methanol and chloroform (1:1, v/v), conventional fucoxanthin extraction from Padina australis yielded 8.12 mg of fucoxanthin per gram of biomass. However, the ultrasonic-assisted extraction resulted in a significantly higher yield of 16.9 mg of fucoxanthin per gram of biomass, demonstrating that the use of ultrasonics enhances the extraction rate compared to conventional methods. Therefore, the efficient separation of fucoxanthin from Padina australis is highly dependent on ultrasonic-assisted extraction. The process conditions for the extraction were optimized to maximize the yield of fucoxanthin from seaweeds. The following parameters were selected for optimization studies: moisture content, particle size, mixing speed, extraction temperature, extraction duration, and solid-to-solvent ratio. The extracted fucoxanthin exhibited various biological activities, including antimicrobial and antioxidant properties, and its structure was elucidated through FTIR and NMR spectroscopy. Additionally, thin-layer chromatography of the crude algae extracts confirmed the presence of fucoxanthin in the marine algae. Given these findings, the optimized extraction process holds the potential for scaling up to large-scale fucoxanthin production. Fucoxanthin, as a potent pharmacological agent, offers promising applications in the treatment of various ailments.