Chitosan is selected as a paper coating material in this study
because it is readily compatible with paper and is therefore a good
comparison when analysing the other biopolymer-paper systems.
Alginate, another naturally occurring polymer, is an anionic
polysaccharide composed of mannuronic acid and guluronic acid
residues and is extracted from seaweed. Alginates are resistant to
solvents, oil, and grease and exhibit interesting film-forming properties.
They are widely used in encapsulation applications due to
their ability to form gels in the presence of cerain divalent cations
such as calcium, barium, and strontium
by ionotropic gelation.