Preparation and Characterization of Waste Fish Bone-Derived Gelatin/Chitosan Plastic Film Incorporated with Green Tea Extract

Abstract

Fish-derived gelatin has recently been spotlighted as an alternative source following the negative issues of mammalian gelatin, but unfortunately it has poor mechanical properties that limit its application. Herein, an environmental-friendly film was prepared from milkfish (Chanos chanos) bone waste-derived gelatin and modified by adding chitosan, glycerol and sorbitol plasticizers as well as green tea extract to improve its mechanical properties. Gelatin was processed from milkfish bone waste using various concentrations of H2SO4 solution (2%, 3%, and 5%) (v/v) and soaking times of 18 h and 36 h for each of the solutions. The measurement test of pH, ash content, and moisture content were conducted on the gelatin product, and the characteristic functional groups were investigated using Fourier- Transform Infrared Spectroscopy (FTIR). The effect of green tea addition was also evaluated on the thickness, tensile strength, and elongation of the resulting films. The results showed that treatment using H2SO4 concentration of 3% with 36 hours of immersion time produced the best gelatin quality with a pH value of 5.9. Water content and ash content were 14.286% and 3.09%, respectively. The plastic film from this study has mechanical properties similar to polypropylene plastic so that it is expected to be a potential material for food packaging applications.