Starch-based biodegradable active intelligent packaging with color superimposition via emulsion electrospinning nanofiber for meat freshness monitoring and shelf-life extension.

Developing sustainable and multifunctional intelligent packaging systems has emerged as a highly promising approach to reducing plastic pollution, minimizing food waste, and enhancing food safety. In this research, a biodegradable intelligent active packaging with a dual pH-responsive system was created by incorporating fat-soluble curcumin (CUR) and water-soluble roselle anthocyanins (RSA) into core and shell, respectively, of starch-based fibers using emulsion electrospinning. Octenyl succinic anhydride starch/polyvinyl alcohol complexes functioned as both fiber wall materials and emulsifiers, stabilizing double-loaded nano-emulsions (88.19 ± 8.33 nm) while conferring auto-degradability to fibers within 5 d without contamination risks. The core-shell structure construction and oil-phase loading improved mechanical strength of fiber around 4 times (8.74 ± 0.17 MPa), elevated the water contact angle to 75.32 ± 2.32°, and lowered the water vapor transmission rate to 4.94 × 10-10 g·cm/(cm2·s·Pa), while enhancing thermal stability and UV resistance. More crucially, the color response range and sensitivity (response process <130 s) of fiber were broadened under the superposition of internal-external color effects of CUR in core layer and RSA in shell layer, resolving accuracy limitations of single-indicator systems. When applied to shrimp and pork packaging, CUR's controlled release delayed spoilage while fiber color parameters demonstrated strong correlation with spoilage indicators such as TVB-N (R2 > 0.92). In summary, this eco-friendly strategy, leveraging emulsion electrospinning with internal-external co-loading of dual pH-responsive systems, offers a versatile design concept for replacing plastics and advancing intelligent food packaging, with significant potential for future applications in food commercialization.