An investigation of antioxidant properties of chitosan extracted from Prawn (Macrobrachium nipponense) shells

Chitosan is one of the most important bioactive polymers which is derived from chitin deacetylation. In the present study, some chitosan samples were prepared from extracted prawn shells chitin at different times. Antioxidant characteristics of the obtained chitosans in 60, 80 and 100 minutes (C60,C80 and C100) were evaluated by antioxidant activity, scavenging activity of 2 and 2 difinyl, 1-picyryl-hydrazyl (DPPH) radical assay, peroxide Hydrogen radical scavenging assay, Reducing Power and iron Chelating Assay . The reducing power values at10 mg / ml was recorded between 0.24-0.26.At 10 mg/ml, the inhibitory ability for DPPH radical was 26.2% for C60, while the C80 and C100were shown more abilities to remove this radical about 44.4% and 50.4%, respectively.The inhibitory power of hydrogen peroxide radicals and iron chelating at 1 mg / ml were in the range of 58.46 to 75.6%, and 64.3 to 86.8%respectively. All EC50 values of antioxidant activity were below1.4 mg/ml. The antioxidant properties of the chitosans showed direct correlation with N-deacetylation times. As the increasing in the N-deacetylation time has led to increase antioxidant activities of chitosans (C60, C80 and C100). In general, prawn shell chitosans have an appropriate antioxidant activity and can be used as an antioxidant source in the food supplement and pharmaceutical industry.