Dual-functional shikonin-loaded quaternized chitosan/polycaprolactone nanofibrous film with pH-sensing for active and intelligent food packaging

Recently, intelligent packaging has emerged for monitoring food quality in food industry. This study aimed to develop the electrospun HACC/PCL/SKN nanofibrous films with improved antimicrobial and antioxidant activity as intelligent packaging to monitor food freshness. The SKN loading resulted in nanoscale uniform fibers (approximately 55.0 nm), and the HACC/PCL/SKN nanofibrous films presented improved hydrophobicity, barrier properties and mechanical properties. Release kinetics study demonstrated that the loading effect led to a sustained release of SKN from fibers. The HACC/PCL film containing 2 wt% SKN showed good antibacterial effect during 24 h, suggesting enhanced antimicrobial activity. Moreover, the SKN-based solutions and films exhibited pH-responsive color changes from red (pH 2) to blue-purple (pH 12). Finally, the HACC/PCL/SKN film effectively provided a spoilage indication for shrimp stored at different temperatures for 3 days by color changes. This work provides a promising strategy for developing multi-functional film as an intelligent packaging in food industry.