Development of Halochromic and Bioactive Polyvinyl Alcohol Films Enriched With Kalanchoë blossfeldiana Anthocyanins...

This study developed halochromic polyvinyl alcohol (PVA) films incorporated with anthocyanins extracted from Kalanchoë blossfeldiana leaves (KBA1-KBA3) for intelligent food packaging. Anthocyanins were obtained using acidified ethanol and purified via column chromatography before incorporation into PVA via solvent casting. The addition of anthocyanins increased film thickness (0.124 to 0.170 mm), opacity, solubility, and swelling degree, while reducing water contact angle (86.21° to 68.31°) and enhancing hydrophilicity. Water vapor permeability increased, and color parameters (L*, a*, b*) shifted markedly with pigment loading. AFM revealed increased surface roughness, correlating with reduced tensile strength and flexibility. Films exhibited strong antioxidant activity (~70% DPPH and ABTS scavenging) and antimicrobial effects, with inhibition zones up to ~8 mm against E. coli and S. aureus . Thermal analysis indicated decreased stability with anthocyanin incorporation. Applied to chicken filet storage, the films showed clear, progressive halochromic color changes aligned with spoilage markers-pH increase (3.2 to 8.5), TVB-N (> 30 mg N/100 g), and peroxide value (13.26 meq O₂/kg) over 14 days. This is the first report using K. blossfeldiana anthocyanins in intelligent packaging, demonstrating their multifunctional potential for sustainable meat freshness monitoring.