Biodegradable film based on cottonseed protein isolated and pectin enriched with <i>Salix aegyptiaca</i> extract microcapsules and chitosan nanoparticles

The objective of this novel research was to examine the unique effects of Salix Aegyptiaca extract microcapsules (MEX; 0, 7.5, 15% v/v) and chitosan nanoparticles (NP S; 0, 2, 4% w/v) within a central composite design on the physicochemical and structural properties of bionanocomposite films based on cottonseed meal protein isolate/pectin. The results showed that the thickness, moisture content, solubility, and antioxidant capacity, increased, while Hue angle decreased ( p ≤ .05). Furthermore, the tensile strength and elongation at break of the samples increased significantly. Fourier-transform infrared spectroscopy and scanning electron microscopy results confirmed minor alterations in the chemical structure and strong molecular interactions between the biopolymer network and the factors under investigation. In addition, X-ray diffraction, differential scanning calorimetry, and antimicrobial activity analyses respectively indicated a decrease in crystallinity index, an increase in thermal stability, and an expansion of the inhibition zone diameter against both Gram-positive and Gram-negative bacteria with the addition of the extract and nanoparticles compared to the control sample. In conclusion, based on all results, it can be stated that the two unique factors examined in this study enhanced the structural and physicochemical properties of the produced film, thereby highlighting its potential application in food packaging to extend the shelf life of the product.