Developing a novel, low-cost, antimicrobial, and biodegradable pectin/HEC/ZnO biofilm for edible food packaging applications

The purpose of this study was to investigate the potential of pectin extracted from orange waste by acid hydrolysis and prepared Pectin/ hydroxyethyl cellulose (HEC)/ZnO nanoparticles (ZnO-NPs) biofilm for food packaging applications. The pectin/HEC/ZnO biofilms were prepared in an aqueous solution at room temperature using solvent casting method and characterized by different techniques such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscope (SEM). Also, thermal gravimetric analysis (TGA), mechanical properties, and water vapor permeability-WVP were evaluated. Moreover, its antimicrobial activity against Gram negative bacteria ( Escherichia coli , Pseudomonas aeruginosa , and Salmonella enterica Typhimiurium) and two Gram positive bacteria ( Listeria monocytogenes and Staphylococcus aureus ), and also has antifungal activity against Candida albicans was assessed. The obtained results display that the water vapor permeability (WVP) indicated a reduction in permeability with increased ZnO concentration, with WVPs ranging from 2.55 × 10 −12 to 4.28 × 10 −12 gm/pas.m 2 , which indicates that our pectin/HEC/ZnO bionanocomposite biofilm could efficiently decrease moisture transfer, thereby potentially extending the shelf-life of packaged food products. Furthermore, the results showed enhanced tensile strength and flexibility in the biofilms with the addition of 1% ZnO nanoparticles from 1.2 to 2.6 MPa and 4.5 to 13 MPa respectively. The WVP indicated a reduction in permeability with increased ZnO concentration, with WVPs ranging from 2.55 × 10 −12 to 4.28 × 10 −12 gm/pas.m 2 . The antimicrobial activity against pathogens such as Escherichia coli , Pseudomonas aeruginosa , Salmonella enterica Typhimurium, Listeria monocytogenes , Staphylococcus aureus , and Candida albicans was significant, with a 99.96% reduction in E. coli counts at a biofilm concentration of 200 mg/mL. Furthermore, the current study revealed that the synthesized bionanocomposite biofilms had excellent qualities such as transparency, flexibility, low cost, and being environmentally friendly. The pectin/HEC/ZnO bionanocomposite was found to be an ideal biofilm for food packaging due to its safety and affordability, which is able to prolong food shelf-life.