In general, the degree of deacetylation of chitosans positively correlates with their ability to adsorb transition metals and scav- enge free radicals (Burke et al., 2000; Park et al., 2004; Xue et al., 1998). The above-described results indicate that the chitosan with a DD of 95% adsorbed more transition metals than did the chitosan with a DD of 85%, especially for copper and manganese. Thus, the chitosan with a DD of