Biological Modification Of Chitosan And Its Application

In this paper, chitosan, whose deactivation degree was different, was hydrolyzed by three kinds of nonspecial enzymes, which were lipase, papain and lysozyme. Then eliminating OH and lard antioxidation of chitosan hydrolyzed were studied.The main contents of experiment were as follows:Fixup dose of chitosan, as index with viscosity chitosan and output of chitosan hydrolyzed, the lipase was added to chitosan whose deactivation degree was different- acetic acid solution, pH value and temperature were regulated, and hydrolyzation reaction was occurred. The experiment results were: The result was different with changes of reactive condition. The best condition of the hydrolyzation reaction of lipase was: deactivation degree was 79%, the dose of lipase was 26ml (corresponding to the best lipase energy 10400u of hydrolyzed chitosan), the temperature was 48.3,pH value was 5. The biggest influence was dose of lipase and the smallest influence was deactivation degree. The lipase can hydrolyze not only GlcNAc group of chitosan indican bond but also GlcN group of chitosan indican bond.Fixup dose of chitosan, as index with viscosity of chitosan, the papain was added to chitosan-acetic acid solution, the influence of the dose of papain, pH value and temperature on hydrolyzation reaction was studied. The mechanism of hydrolyzation reaction was discussed primarily. The experiment results were: The best condition of the hydrolyzation reaction of papain was: deactivation degree was 66%, the dose of papain was 20ml (corresponding to the best papain energy 9260u of hydrolyzed chitosan), the temperature was 67,pH value was 4.84. the hydrolyzation capacity of papain was better than that of lipase. The papain only hydrolyzed {3 (1,4) indican bond of chitosan which link GlcNAc cell with GlcN cell. The chitosan hydrolyzed was analyzed by HLPC. The result indicated monomer was most.Fixup dose of chitosan, as index with output of chitosan hydrolyzed, the chitosan was hydrolyzed by lysozyme, and the best condition was: deactivation degree was 57.5%, the dose of lysozyme was 3ml (corresponding to the best lysozyme energy 1.2 106u of hydrolyzed chitosan) , the temperature was 34,pH value was 5.9. The lysozyme onlyhydrolyzed (1,4) indican bond of chitosan which links GlcNAc cell. The chitosan hydrolyzed was analyzed by HLPC. Chitooligosacchalides whose polymeric degree was 1 to 4.According to the Smirnoff method improved, the eliminating capacity to OH of chitosan which hydrolyzed by three kinds of emzyme was studied. The result indicated: they all have the eliminating capacity to OH. The eliminating capacity of chitosan hydrolyzed by lipase was best. And the antioxidation of monomer was little, but the antioxidation of other chitooligosaccharides was better.The lard antioxidation of chitosan which hydrolyzed by three kinds of emzyme was studied. The result indicated: they all have the better lard antioxidation. Especially , the lard antioxidation of chitosan hydrolyzed by lipase was best and better than VE. And the mechanism of antioxidation was discussed primarily.