Properties and Characteristics of Fish Skin Gelatin-Based Three-Layer Film Developed with Bioplastics and Physalis Leaf Extract

The impact of incorporation of Physalis leaf extract (PLE) at various levels on properties and characteristics of the gelatin based three-layer film (Poly (lactic acid)/Gelatin/Poly (butylene adipate-co-terephthalate) was investigated. Three-layer films were developed by a three-step casting process and each layer of film was incorporated with PLE at 0–15% (w/w). Young’s Modulus (525.19-164.24 MPa) and tensile strength (22.38–8.38 MPa) of three-layer films decreased with augmented level of PLE (p < 0.05), in contrast elongation at break (13.80-142.56%) was increased (p < 0.05). In general, the incorporation of PLE resulted the three-layer films with lower water vapor permeability ranged from 1.442 to 1.019 × 10^–11 g.m.m^− 2.s^− 1.Pa^− 1 than the control counterpart (P/G/B-PLE-0%) (without PLE) (1.473 × 10^–11 g.m.m^− 2.s^− 1.Pa^− 1) (p < 0.05). Greenness (-a* value) of the resulting films increased with augmenting incorporation ratios of PLE (p < 0.05). The lower transparency value (7.41) was recorded for control film (without extract) (p < 0.05). However, PLE incorporated three-layer film exhibited compact structure as revealed by SEM micrographs. Thermal properties of obtained three-layer film were impacted by the addition of plant extract. Thus, the enhanced water vapor barrier property and improved elasticity were obtained for PLA/Gelatin/PBAT films incorporated with PLE.