Abstract
Carboxymethyl cellulose (CMC) based edible films, reinforced with date seed powder (DSP) were investigated. An increasing concentration of DSP (5%, 10%, 15%, and 20%) was added to the carboxymethyl cellulose film-forming solution. The physical, antioxidant, antibacterial, mechanical, structural, and thermal properties of the films were studied to investigate the effect of DSP incoportation. The addition of DSP increased the thickness of the films from 0.11 to 0.15 mm, reduced the solubility (95.31-77.23%), and exhibited antibacterial activity against the food-borne pathogens: Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Salmonella typhimurium. Especially for Escherichia coli, and Salmonella typhimurium, the antimicrobial activity was seen only at high concentrations (15% and 20%) of DSP. Besides, the antioxidant capacity increased with increasing concentration of DSP: the DPPH radical scavenging activity increased from 0 to 51.98% while ABTS increased from 0 to 84.58%, when the concentration of DSP increased from 0 to 20%. In addition, the water vapor permeability of the films improved but the tensile strength decreased from 7.66 MPa to 5.12 MPa and the elongation at break increased from 79.03 to 85.95%. This study clearly showed that the DSP could be valorised as an active and reinforcing component in CMC-based biodegradable and edible films to create natural active food packaging.