Rational design of chitosan/guar gum/zinc oxide bionanocomposites based on Roselle calyx extract for Ras cheese coating.

Roselle calyx extract (RE) was used to prepare zinc oxide nanoparticles (ZnO-NPs) as a green technique. In the current work, chitosan/guar gum/zinc oxide bionanocomposites based on Roselle calyx extract, namely (CS/GG/RE-ZnO) bionanocomposite were prepared. The synthetic ZnO-NPs and the prepared bionanocomposites were characterized by Fourier transforms infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Moreover, the addition of RE-ZnO nanocomposites was improved mechanical, permeability, antimicrobial and antioxidant properties of bionanocomposite films. The influence of coating Ras cheese with the fabricated CS/GG/RE-ZnO bionanocomposites on chemical, microbiological, and sensorial properties of Ras cheese was evaluated during ripening in comparing with uncoated cheese. Ras cheese coating with bionanocomposite film containing 3% RE-ZnO nanocomposites protects their surface for around three months from yeasts, molds and other bacteria growth. The prepared CS/GG/RE-ZnO bionanocomposite films can be used as a promising candidate for food packaging applications.