Valorization of fish scale waste for the synthesis of functional gelatin-based biopolymers

This study investigated the potential of extraction and characterization of bioplastics from Catla catla fish scale gelatin as a sustainable alternative to petroleum-based polymers. The extraction process involved NaCl and NaOH treatments, EDTA demineralization, acid solubilization, and thermal hydrolysis. Gelatin was characterized using UV–Visible spectroscopy, Fourier Transform Infrared (FT-IR) spectroscopy, and Scanning Electron Microscopy (SEM). UV-Vis spectroscopic analysis showed absorption peaks below 250 nm, indicating intact peptide bonds. The FTIR spectra displayed amide I and II bands with C–O stretching, confirming protein integrity and plasticization with glycerol. SEM examination revealed the transformation of porous gelatin powder to a smooth biopolymer matrix in the films. The bioplastic demonstrated a pH of 4.72, 5% moisture content, 28% water solubility, and a swelling degree of 32 %, indicating its flexibility and environmental responsiveness. Gel tests confirmed the formation of protein-based gels. Spectral and morphological analyses validated plasticization, supporting the potential of this material for biodegradable packaging and biomedical applications. Thus, the study demonstrates the conversion of fishery waste into biopolymers for use as a sustainable material.