Antioxidant Activity, Morphological Structure, Barrier and Mechanical Properties of Tuna Bone Gelatin-Thalassia hemprichii Leaf Extract-Based Bio-packaging

The development of bio-packaging materials derived from environmentally friendly biopolymers stands for a significant advancement in addressing the growing concern over plastic waste and its detrimental impact on the environment. Gelatin derived from fish bones and bioactive components of seagrass leaf extract can be raw materials to produce bio-packaging as an alternative to plastic. The objective of this research was to obtain a gelatin derived from tuna fish bones and Thalassia hemprichii leaf extracts-based bio-packaging, which exhibits antioxidant activity, favorable mechanical and barrier properties. In addition to the 5% and 7,5% gelatin concentrations and 0,5% and 1% nonpolar seagrass extracts, the heating temperature was also varied at 50, 65 and 80°C. This resulted in a completely randomized factorial design for the experiment. The parameters examined included antioxidant activity, evaluated using the DPPH method; morphological structure, assessed via scanning electron microscopy; and mechanical properties of the films, including tensile strength, elongation, thickness, solubility, and water vapor transmission rate, which were determined using the ASTM method. The results showed that the highest antioxidant activity, with an IC₅₀ value of 67.73ppm, was observed in the bio-packaging formulation comprising 5% gelatin and 0.5% seagrass extract, processed at 65°C. The highest tensile strength (8.42 MPa) was observed in the 7.5% gelatin formulation without extract, processed at 65°C, and with a low water vapor transmission rate when using 0.5% seagrass extract. The highest solubility was seen in the formulation containing 7.5% gelatin and 1% seagrass extract, with a value of 74.52%. The greatest elongation (196%) was observed in the formulation containing 7.5% gelatin and 0.5% seagrass extract, processed at 80°C. Additionally, the thickness of the bio-packaging increased with the addition of seagrass extract. Edible films containing 7.5% gelatin and 0.5% seagrass extract processed at 80°C appear smoother and flatter than the other treatments.