Solvent‐Free Fabrication of Eco‐Friendly <scp>pH</scp> ‐Sensitive Smart Films From Poly(Butylene Succinate) and Red Cabbage Anthocyanin for Tracking of Chicken Breast Spoilage

ABSTRACT The growing interest to ensure food safety requires the development of smart indicator systems that are capable of real‐time tracking of spoilage, particularly for perishable foods. Therefore, the purpose of this work is to fabricate eco‐friendly, industrially viable pH‐sensitive smart films via solvent‐free melt‐compounding, bypassing the limitations of solution casting. Smart films were produced by incorporating red cabbage anthocyanin (ANT) into bio‐based poly(butylene succinate) (PBS) matrix via melt compounding and compression molding at 135°C. Morphological, structural, thermal, mechanical, and functional properties were examined as a function of ANT loading rate (1–10 wt%). Thermal and tensile tests revealed that increasing ANT loading rate led to a reduction in crystallinity (from 47% to 37%) and tensile strength (from 13 to 2 MPa), while antibacterial activity against Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ) was significantly enhanced at loading rates ≥ 5 wt%. Thermal stability remained sufficient for melt compounding, with initial degradation temperatures exceeding 190°C. Particularly, 5ANT and 10ANT films showed distinct color transitions from red to purple/blue across a pH range of 2–12. These films also demonstrated pH‐sensitive color changes when applied to real‐time tracking of chicken breast spoilage over 4 days, confirming their efficacy as industrially scalable freshness indicators.