PRESSURIZED FLUID EXTRACTION OF BIOACTIVE NUTRACEUTICALS FROM MARINE BIOMASS

Various species of marine macroalgae contain bioactive compounds including carotenoids, proteins and polysaccharides. Fucoxanthin, the main carotenoid component, is known to possess numerous therapeutic functions. Similarly, low-molecular-weight fucoidan and peptides also exhibit several functions including antioxidant activities, antitumor and anti-aging effects. This paper highlights the use of supercritical carbon dioxide (SCCO2) and subcritical water, an environmentally benign solvent for extraction of these useful compounds. Results indicated that SCCO2 extraction could recover the lipids obtaining fucoxanthin with a recovery close to 80%. We also found that crude extract was more potent than pure fucoxanthin against HepG(2) (liver) cancer cells. Subcritical water treatment was also performed using the extraction residues obtaining the target LMW fucoidan of 5-30 kDa even at a low temperature of 140 degrees C. The use of semi-batch reactor for simultaneous fractionation and separation of target molecular weights was also investigated. The advantages of coupling the process with microwave irradiation is also introduced and discussed.