Production and optimization of green tea extract and boron nitride nanoparticles doped chitosan/sodium caseinate nanocomposite film for food packaging

This study presents the preparation and characterization of novel chitosan/sodium caseinate bio-nanocomposite films doped with green tea extract and boron nitride nanoparticles. Different films were prepared with varying amounts of sodium caseinate, green tea extract, and boron nitride. Moisture content, water and vapor swelling, pH-dependent solubility, optical and color properties, antimicrobial activity, mechanical strength, total phenol, and antioxidant properties of films were studied. As the sodium caseinate ratio increased, the moisture content, swelling degree, tensile strength, and elongation decreased. The results indicated that green tea extract and boron nitride improves properties of the films. The addition of GTE and BN significantly increased mechanical strength and decreased moisture content. The lowest moisture content of 16.67%, the highest total color difference of 27.58, and the highest antioxidant activity of 93.6% were obtained with 1 vol% of green tea extract loaded chitosan/sodium caseinate films. The lowest water swelling degree of 51.22% and the highest tensile strength of 11.35 MPa were obtained with 1 wt% boron nitride-loaded chitosan/sodium caseinate films. The incorporation of boron nitride increased the antimicrobial effect, while the green tea extract additive increased the degradation rate in soil.