Chitosan extracted from mud crab (Scylla olivicea) shells: physicochemical and antioxidant properties

The aim of this study is to report the yield of extraction, as well as the physicochemical and antioxidant properties of extracted chitosan from mud crabs (S. olivacea) as compared to commercial chitosan. The yield obtained for extracted chitosan was 44.57+/-3.44% with a moisture and ash content of 9.48+/-0.59 % and 5.97+/-0.90 %, respectively. Commercial chitosan demonstrated a higher degree of deacetylation (58.42+/-2.67 %), water (250+/-9.90 %) and fat (329+/-7.07 %) binding capacity, solubility (73.85 %), viscosity (463.25+/-13.10 %) and also the whiteness value (77.8+/-0.47) compared to the extracted chitosan, which were only 53.42+/-0.88 %, 180+/-0.00 %, 260+/-0.00 %, 53.38 %, 383.9+/-28.43 % and 62.1+/-7.52 %, respectively. The structure of extracted and commercial chitosan was also investigated using Fourier Transform Infrared Spectroscopy (FTIR). In conclusion, the extracted chitosan possessed potential properties similar to the commercial chitosan with high reducing power but low in the scavenging activity on the DPPH and hydroxyl radicals compared to the commercial chitosan.