Microwave-Assisted Extraction of Fucoidan from Brown Seaweeds of Nizimuddinia zanardini and Assessment of the Chemical and Antioxidant Properties of the Extracted Compound

In the past decade, sulfated fucose-rich polysaccharides (fucoidan) have been much interested due to their diverse biological activities, including anticoagulant, antiviral, antitumor, anti-inflammatory, anti-blood lipid, antioxidant, gastric protection and therapeutic activities. In the present study, microwave was used as a green efficient technology for the extraction of bioactive compounds of fucoidan from Iranian macroalgae (Nizimuddinia zanardini). In addition, effects of microwave on chemical composition and antioxidant activity of fucoidan were assessed.

Fucoidan polysaccharides were extracted under optimized conditions of microwave power, processing time and temperature. The compound characteristics, including extraction efficiency, fucose content, sulfate content, uronic acid content and DPPH radical scavenging were assessed. Fourier-transform infrared spectroscopy was used at wavelengths of 400–4000 cm-1 at room temperature.

Results showed that microwave treatment was effective in improving the extraction yield of fucoidan. Fucoidan extraction yields under the microwave technique included 3.71 and 2.35%. The fucose content under the microwave technique (33.17%) was compared to that under the conventional technique (29.5%) with significant increases, indicating less thermal degradation of the polysaccharide structures under the microwave technique. The microwave improved fucoidan antioxidant activity by producing shorter chain polysaccharides.

In this study, fucoidan sulfated polysaccharides were extracted using microwave extraction technique in a much shorter time than the conventional extraction technique with higher efficiency and lower thermal degradation. In addition, the shorter process time decreased solvent use.