ABSTRACT
Marine polysaccharides in seaweeds exhibit unique rheological and biological properties. Developing efficient extraction processes opens new ways to utilize marine polysaccharides as feedstock for various applications. Microwave (MW) technology is one of the key methods employed to separate polysaccharides from the matrix and cell wall in seaweeds. MWs directly activate molecular motions of water molecules and electrolytes inside the algal bodies and generate heat from within. Nonequilibrium heating inside the algal cells enhances diffusion of molecules from their bodies, leading to high extraction yields even at short duration of extraction. The use of water as an extraction solvent further contributes to the appeal of MW irradiation as an attractive environmentally friendly process. Oligosaccharides can also be prepared by autohydrolysis of marine polysaccharides under precise control of MW irradiation. This chapter summarizes practical MW-assisted extraction and hydrolysis process of marine polysaccharides. Fundamental MW heating mechanisms and dielectric properties of materials are also described to understand the mechanisms of extraction process under MW irradiation.
