Brazilin-loaded biodegradable electrospun membranes with tunable release for active and intelligent food packaging

Food waste and safety challenges demand sustainable packaging solutions that extend shelf life and provide real-time spoilage indicators. This study reports the fabrication and characterization of electrospun poly(lactic acid) (PLA) and poly(ethylene glycol) (PEG) membranes incorporating brazilin, a natural polyphenolic compound with antioxidant, antimicrobial, and pH-responsive dye properties. Monoaxial and coaxial electrospinning were employed to tailor fiber morphology and release kinetics, enabling modulation from rapid to sustained diffusion. Scanning electron microscopy confirmed uniform micro-fibrous structures, with coaxial fibers exhibiting reduced diameters and smaller pore sizes relative to monoaxial counterparts. Release studies demonstrated tunable profiles, with monoaxial fibers achieving near-complete release within 24 h, while coaxial configurations extended release over three weeks. Antioxidant assays (ABTS, FRAP) verified strong and persistent activity, consistent with both hydrogen atom transfer and electron transfer mechanisms. Antimicrobial testing showed significant inhibition of Staphylococcus aureus, whereas Gram-negative bacteria remained resistant, underscoring the need for combinatorial strategies. The membranes also displayed robust, reproducible colorimetric transitions (yellow–orange–red) across acidic, neutral, and alkaline pH, confirming their suitability as freshness indicators. Collectively, these findings establish brazilin-loaded electrospun membranes as multifunctional, biodegradable packaging materials that integrate active protection with intelligent sensing. By uniting sustained antioxidant activity, targeted antimicrobial efficacy, and visible spoilage indication, this work advances the development of next-generation packaging technologies that enhance food quality, safety, and sustainability. Future studies should validate performance in real food matrices and explore synergistic antimicrobial combinations to broaden efficacy