2nd cascading phase

In the 2nd cascading phase focus will be on development of scalable and sustainable extraction/separation methods for the production of multiple products from brown seaweed or seaweed residues by means of enzyme aided physicochemical/mechanical methods. Various pre-processed seaweed samples from WP 2 and seaweed residues from WP 3 will be fractionated into raw fractions rich in alginate, fucoidan, mannitol, laminarin or proteins. For this MACRO CASCADE will make use of structural differences between easily hydrolysable and more recalcitrant structures in seaweed. If possible, these raw fractions will be further processed for specific applications in WP5.

Target intermediate products are:

Alginate is on commercial scale extracted from brown seaweed. It is used for thickening of aqueous solutions, formation of gels by replacement of monovalent cations by calcium, and film formation. Based on technical specifications, hydrocolloids from seaweed can be applied beyond food, pharmaceutical and biomedical areas.

Fucoidan is a group of sulphated polysaccharides primarily composed of sulphated fucose with <10% of other monosaccharides. It is found in the cell wall of brown seaweeds where is protects the plant from dehydration and retains water. Fucoidans have been noted to have a variety of biological activities of which anticoagulant properties are most commonly studied. (Biological) activity is strongly dependent on the structure of the polysaccharide and as such on the method of isolation or extraction. In addition, it is a naturally occurring anionically charged polysaccharide with possibly broad applications.

Mannitol is a sugar alcohol (polyol) which is currently being used mainly in the food and pharmaceutical industry. Since uptake of mannitol is independent of insulin, it is also applicable in diabetic food products. Commercial production of mannitol is mainly done by reduction of fructose leading to mannitol and sorbitol (isomers) in equal parts. Hydrolysis of sucrose followed by catalytic hydrogenation also leads to mannitol and sorbitol in a molar ratio of 1:3.Due to current drawbacks of mannitol production (mannitol from fructose or sucrose is always accompanied by the production of sorbitol), research efforts have been directed towards developing new techniques for the production of pure mannitol.

Proteins are applied as feed (additive) or can be used as source for amino acids. Properties of seaweed proteins are highly dependent on method of isolation.