Enhanced physicochemical properties of chitosan films with in situ generation of kafirin particles: optimization via...

Biodegradable food packaging has gained significant attention owing to environmental concerns. Chitosan (CS), a natural polysaccharide, is popular in packaging films, however, its high hydrophilicity, brittleness, and low mechanical strength limit its use. To improve CS film performance, kafirin (Kaf), glycerol (GE), and tannic acid (TA) were added to create biocomposite films. The response surface method (RSM) was used to develop predictive models, with Kaf, GE, and TA as independent variables. Optimal film properties were achieved with a CS to Kaf ratio of 9 : 1, 20% GE as a plasticizer, and 5% TA. The addition of Kaf and TA increased the tensile strength and improved hygroscopicity, solubility loss, swelling, and water contact angle. GE enhanced the film flexibility. Overall, the composite films showed improved mechanical strength, water resistance, and UV resistance, indicating strong potential for food packaging applications.