Gelatin base edible film and preparation method thereof

A preparation method of a gelatin base edible film, including the following steps:

• a) preparing gel nanoparticles, comprising:
• a1) dissolving gelatin in water to obtain a gelatin solution, and adding a ε-polylysine solution into the gelatin solution to react and obtain a first solution;
• a2) adding a genipin solution into the first solution obtained in step a1) to react and obtain a second solution;
• a3) adding 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) into the second solution obtained in step a2) to mix, then reacting in an ice bath and then reacting at room temperature to obtain a double-network polymer;
• a4) removing excess EDC and genipin from the double-network polymer obtained in step a3), then pulverizing the double-network polymer to obtain the gel nanoparticles;
• b) preparing bacterial cellulose nanoparticles
• grinding a bacterial cellulose into bacterial cellulose nanoparticles under the condition of liquid nitrogen freezing;
• c) preparing the gelatin base edible film
• mixing pullulan, glycerin, nisin, antibacterial peptide, the gel nanoparticles obtained in step a) and the bacterial cellulose nanoparticles obtained in step b), ultrasonically degassing, then the resulted system being subjected to coating and drying to form a film to obtain the gelatin base edible film.