Fabrication of biodegradable carboxymethylcellulose-based antioxidant packaging film incorporated with pineapple waste-synthesized ZnONPs for apple preservation

Conventional plastic packaging is non-degradable and highly persistent, leading to environmental pollution and posing threats to wildlife and human health. Alongside these environmental issues, extending food shelf life is essential, as food spoilage has become a major concern, causing economic losses and compromising food safety and quality. This study aims to incorporate different concentrations of zinc oxide nanoparticles (ZnONPs; 0.5, 1, and 1.5% wt.) synthesized from pineapple peel extract into carboxymethylcellulose (CMC) to produce an active food packaging film. The structural and chemical characteristics, as well as physical, mechanical, barrier, and thermal properties of the fabricated film were analyzed accordingly. In addition, its functional properties, antioxidant activity, and biodegradability were further evaluated for biodegradable active packaging films. Notably, the active film with synthesized ZnO (1.5% wt.) demonstrated excellent performance, achieving a 20.53% reduction in moisture content, a 41.31% reduction in water solubility, enhanced thermal stability and barrier properties, and improved tensile strength and elongation at break compared to films made solely from CMC. The film exhibited up to 50.46% antioxidant activity, with the highest performance at 1.0 wt% ZnO effectively delayed the deterioration of apple slices for up to 9 days of storage. These findings indicate that the fabricated CMC/ZnONPs film has great potential as an active food packaging.