Influence of pH and protein concentration on the development of myofibrillar protein-based biodegradable film from Basa (Pangasius bocourti) fish waste

Fish waste generated by fish-processing industries contributes significantly to environmental pollution, highlighting the need for its effective utilization. Similarly, plastic waste from packaging industries poses serious environmental and health concerns. In this study, a biodegradable film was developed using myofibrillar protein obtained from Basa (Pangasius bocourti) fish waste. Protein concentrates at different concentrations (0.5, 1.0, and 1.5%) were used to prepare films under two pH conditions (2.8 and 11.0). The films were evaluated for their tensile strength, elongation at break, water vapor permeability, water solubility, and color characteristics. Among the formulations tested, the film prepared with 1% protein concentrate at pH 2.8 exhibited the highest tensile strength (6.86 MPa), the lowest water solubility (28.1%), and a lower increase in yellowness during storage compared to the other films. Films developed under acidic conditions showed greater disulphide interactions and a smoother surface morphology than those prepared under alkaline conditions. Thus, a myofibrillar protein-based biodegradable film was developed and it was systematically demonstrated how pH and protein concentration affect their mechanical, barrier, and physicochemical properties. The innovation of this work lies in integrating Basa fish waste valorization with pH-mediated protein engineering to develop biodegradable films.