Study on the function of orange essential oil in optimizing fish scale gelatin films

In order to improve the performance of the fish scale gelatin film, the edible films were added with 0%, 25%, 50%, 75% and 100% orange essential oil (OEO) of gelatin quality. The thickness, mechanical properties, water solubility, water vapor permeability (WVP), color, transparency, light transmittance, thermal properties, infrared spectra and antibacterial activity of the composite films were investigated. With the increasing of OEO, the thickness, elongation at break (EAB) of the gelatin films increased and tensile strength (TS), light transmittance, water solubility decreased, while WVP increased first and then decreased. Differential Scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) analysis showed that fish scale gelatin molecules interacted with and some components of OEO and the thermal stability of the gelatin films was improved to some extent. The films exhibited strong antibacterial activity due to the corporation of OEO. In conclusion, edible films incorporated 75% OEO optimized all the best properties of the fish scale gelatin films. The experimental results could provide a theoretical basis for the production of superior fish scale gelatin films.