A Comparative Study on the Physicochemical Characterization of Chitosan Obtained from Seafood in Uyo Metropolis, Nigeria

One biopolymer that stands out for its uses in biotechnology and pharmaceuticals is chitosan, whose functionality is often influenced by the source of the material. The primary focus of this study was to derive and analyze chitosan from three different types of seafood shells: crab (Callinectes amnicola), periwinkle (Tympanotonus fuscatus var. radula), and snail (Archachatina marginata) collected from Uyo Metropolis, Akwa Ibom State, Nigeria. Chitin was first extracted from the exoskeletons of these organisms and subsequently converted into chitosan using the chemical method. The derived chitosan samples were characterized and compared with commercial chitosan. Yield analysis revealed values of 29.80% for crab, 16.31% for periwinkle, and 39.80% for snail. All samples had a degree of deacetylation above 50%. Fourier Transform Infrared Spectroscopy (FTIR) analysis showed consistent features, including O-H stretching vibrations, N-H amine groups, alkyl peaks, and glycosidic bonds characteristic of chitosan. Despite chemical similarities, physical differences were observed. Snail chitosan had high thermal stability but low crystallinity, whereas crab and periwinkle chitosan samples showed moderate crystallinity. The commercial chitosan was highly crystalline. Ash content was highest in periwinkle-derived chitosan (10.46%). While all chitosan samples demonstrated comparable solubility, viscosity varied. These findings indicate that while the chitosan samples share core chemical structures, source-specific differences in physical properties may influence functional applications. The study concludes that seafood waste provides a viable source of functional chitosan, with varying characteristics influencing their potential uses, especially in pharmaceutical science and technology.