Physicochemical and Antioxidant Properties Based on Fish Sarcoplasmic Protein/Chitosan Composite Films Containing Ginger Essential Oil Nanoemulsion

The appeal for environment friendly films with bioactive components to replace synthetic plastic packaging has been increasing in recent years. In this study, ginger essential oil (GEO) nanoemulsion at different levels (0.5%, 1.0%, 1.5%, 2.0%, and 3.0%) were incorporated into fish sarcoplasmic protein (FSP) and chitosan (CH) blend films to evaluate the physical, mechanical, antioxidant, and thermal properties. The water distribution state of films was also determined by NMR transverse relaxation (T2) measurements. The tensile strength (TS) of samples was significantly reduced with increasing GEO nanoemulsion contents (p < 0.05), while the value of elongation at break (EAB) was the highest when the film with 1.0% GEO nanoemulsion. The addition of GEO nanoemulsion enhanced the water barrier properties and affected the water distributions of films, but had negative effects on thermal degradation of films. Scanning electric microscope (SEM) demonstrated the different microstructure at varied levels of GEO nanoemulsion and Fourier transform infrared (FTIR) spectroscopy gave the detailed information about the interactions at molecular level. These results revealed that FSP blended with CH was excellent film-forming material and mixing defined amount of GEO nanoemulsion into film-forming solution enhanced the physical and antioxidant properties of films.