"Hydrophilic versus hydrophobic extracts: A comparison on synthesis, antibacterial activity, and release mechanisms of red cabbage and capsicum extracts embedded in cellulose acetate films".

This study presents the first successful incorporation of high concentrations (4.5-7.5 % w/w) of hydrophilic red cabbage extract (RCEX) and hydrophobic capsicum extract (CAPEX) into cellulose acetate (CA) films without using any emulsifiers or plasticizers, overcoming key formulation challenges in carbohydrate polymer systems. Molecular docking confirmed strong binding of anthocyanins (RCEX) and capsaicinoids (CAPEX) to bacterial enzymes (DNA Gyrase/Sortase A), with RCEX showing superior in-silico inhibition. However, CAPEX-loaded films demonstrated larger inhibition zones in vitro (24 ± 0.7 mm against E. coli and 10 ± 2 mm against S. aureus), attributed to their faster release (90 % in 72 h) compared to RCEX (50 % in 72 h). RCEX increased film flexibility by 18.7 %, while CAPEX reduced it by 6.5 %, both relative to plain CA films. Additionally, RCEX exhibited higher antioxidant activity and enabled a unique colorimetric response to contamination. Atomic force microscopy showed increased surface roughness upon extract loading, while contact angle measurements confirmed greater hydrophilicity in RCEX films and increased hydrophobicity in CAPEX films (+12 %). These results highlight CA's adaptability in tuning release kinetics, mechanical behavior, and functional properties for bioactive packaging and sensing applications.