Surimi wash water treatment by chitosan-alginate complexes

decreased for samples with lower MW. These results suggest that the effect of MW
on the tensile strength of chitosan films is more dominant than the effect of DD.
Finally, the elongation and the ability of film to absorb moisture decreased with
increased DD.
The effect of MW and DD on drug release has been recently reported.
Using chitosan with 70 and 80% DD, Kofuji and others (2000) found that
degradability of chitosan beads by lysozyme decreased as the DD increased but
drug release was not influenced. Similar results were observed when the same
authors studied the effect of DD on the biodegrability and drug release performance
of chitosan beads tested on mice (Kofuji and others, 2001) using chitosan with 70,
80, 90 and 100% DD. Chitosan gel beads prepared in 10% amino acid solution (pH
9) were subcutaneously implanted in air pouches on the dorsal surface of mice.
Degradation of the beads increased as the chitosan DD decreased. On the contrary,
Chiou and others (2001) found that drug release was independent of MW or DD
but the initial burst decreased as the MW increased. The difference in findings
amongst these results could possibly be due to the different methods of preparation.
Kofuji et al (2000, 2001) mixed the drug directly with the chitosan solutions and
dropped the mixture into 10% glycine to form a hydrogel while Chiou and others
(2001) applied the chitosan solution as a microcapsule coating. Drug release from
the hydrogel beads will solely depend on chitosan while that for the chitosan coated
microcapsules will also depend on the microcapsule used.
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