Isolation and Characterization of Chitosan from Nacre of the Oyster Pearl Shell (Pinctada Maxima) as Biopolimer

Chitosan is derived from the deacetylation of chitin using a strong base. Chitin, a biopolymer commonly found in oyster pearl shells (Pinctada maxima sp), is transformed into chitosan. This study aims to investigate the properties of chitosan extracted from oyster pearl shells, focusing on the effect of variations in NaOH concentration on the chitosan produced. The isolation of chitosan involved deproteinization, demineralization, and deacetylation. Proximate content, functional groups, degree of deacetylation (DD), crystal structure and crystallinity, and particle size were analyzed using proximate testing, FTIR, XRD, and PSA. The study found that both chitosan samples had low water and fat content, displayed typical chitosan functional groups (OH and NH2), and possessed an orthorhombic crystal structure with consistent lattice parameters of 8.24 Å. Chitosan treated with 80% NaOH achieved the highest DD of 88%, the greatest crystallinity of 72.07%, and a particle size of 44.306 µm. In comparison, chitosan treated with 70% NaOH had a DD of 82.61%, crystallinity of 39.65%, and a particle size of 55.509 µm. Thus, variations in NaOH concentration are proposed to have differences in DD, crystallinity, and particle size of chitosan. The research successfully isolated chitosan from oyster pearl shells, but further optimization of process parameters is necessary to enhance its potential as a biomaterial.