Eco-friendly and active carboxymethyl cellulose film integrated with eggshell powder and tea polyphenols for beef and apple preservation.

The food waste resulting from by corruption not only causes huge economic losses to society, but also exacerbates global hunger. In the contemporary context of mounting global environmental awareness and concerns regarding food safety, the utilization of biodegradable active packaging has attracted a considerable attention. In this study, a novel and degradable CGP-ESP-TP film was prepared with wheat straw-based carboxymethyl cellulose (CMC, 2%), glycerol (30% w/w of CMC), eggshell powder (2.5%) obtained by superfine grinding and tea polyphenols, polymalate (0.9%), to the preservation of beef and apples. The 90% particle size of the eggshell powder particles obtained via superfine grinding was found to be less than 8.942 μm. When the concentration of tea polyphenols was 0.20%, the CGP-ESP5-TP4 film has excellent antioxidant and anti-UV properties, tensile strength, elongation at break, oxygen permeability, water vapor permeability and carbon dioxide permeability were 35.84 MPa, 100.96%, 1.44 *10-14 kg·m·m-2·s-1·Pa-1, 1.10 *10-13 g·m·m-2·s-1·Pa-1 and 1.25 *10-14 kg·m·m-2·s-1·Pa-1, separately. According to scanning electron microscopy results, film components, except eggshell powder, had good solubility in the solution. It was also found that non-covalent bonds (eg: hydrogen bonds) were the mainly interaction force between the matrix of the film by the fourier transform infrared spectroscopy spectra. Preservation results indicated that the packaging film lowered the increase in pH, total volatile basic nitrogen and total viable count of beef, as well as the increase in pH and weight loss of apples, and the decrease in apple firmness, which were effectively maintained their quality. The study indicated the significant potential of eggshell powder from waste resources and its transformation into sustainable and biodegradable composites as a promising solution for food packaging applications.