Centrifugally Spun Flaxseed Gum/PEO Fibers Enriched with Kale Extract for Active Food Packaging Applications

The objective of this study was to develop active fibrous packaging materials based on flaxseed gum and polyethylene oxide containing kale extract using centrifugal spinning. In addition, their ability to retard lipid oxidation in olive oil was evaluated. Fibers containing different kale extract concentrations were produced and characterized in terms of morphology, rheological behavior, total phenolic content (TPC), antioxidant activity (AOA), encapsulation efficiency (EE), loading capacity (LC), water vapor permeability (WVP), Fourier transform infrared spectroscopy (FTIR), thermal properties, and oxidative stability. Kale extract incorporation significantly increased fiber diameter while maintaining continuous bead-free morphologies. Rheological analyses demonstrated the suitability of flaxseed gum/PEO solutions for centrifugal spinning. The incorporation of kale extract significantly enhanced TPC and AOA, whereas EE values ranged from 32.32% to 95.78%, indicating successful encapsulation of bioactive compounds. Differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) confirmed molecular interactions and adequate thermal stability of the developed fibers. Oxidative stability analyses showed that kale extract-loaded fibers effectively delayed lipid oxidation in olive oil. Among all formulations, fibers containing 5% kale extract exhibited the strongest oxidative protection, reducing p-anisidine value (PAV) and total oxidation value (TOTOX) by 25.1% and 23.86%, respectively. These findings highlight the potential of kale extract-enriched flaxseed gum/PEO fibers as sustainable active packaging materials.