Asian Journal of Fisheries and Aquatic Research

Fish processing in tropical countries generates substantial quantities of waste, including scales, heads, and fins, which may be discarded into soil and water. This study investigated the recovery of chitosan from waste scales of Labeo rohita collected in Lucknow, Uttar Pradesh, India. The scales were washed, sun-dried, and subjected to sequential demineralization, deproteinization, and deacetylation. The recovered chitosan was evaluated for yield, degree of deacetylation, moisture content, ash content, and solubility. Structural, morphological, and thermal characteristics were examined using Fourier-transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The extraction process produced a chitosan yield of 27%. The degree of deacetylation was 62.71%, while the moisture and ash contents were 3.16% and 0.962%, respectively. The material was soluble in a 1% aqueous acetic acid solution. The infrared spectrum contained bands associated with hydroxyl, carbon-hydrogen, amide, carbon-nitrogen, and carbon-oxygen groups. Scanning electron micrographs showed irregular, non-homogeneous, agglomerated particles with a rough surface and visible pores. Thermogravimetric analysis indicated an initial loss associated with adsorbed moisture, followed by degradation of the polymeric structure. These findings document the recovery and physicochemical characterization of chitosan from discarded L. rohita scales under the extraction conditions used in this study.