Bioactive biopolymer films reinforced with cellulose nanocrystals and green-extracted polyphenols from date seeds for veal meat preservation

This study investigated the effectiveness of bioactive films fabricated using chitosan (Cs) reinforced with cellulose nanocrystals (CNC) and polyphenolic components extracted using natural deep eutectic solvents (NADES), both derived from date seeds. The CsCNC films with NADES-extracted date seed polyphenols (DSP) showed significant antimicrobial activity against Staphylococcus aureus, Listeria monocytogenes, Salmonella typhimurium, and Escherichia coli. Total phenolic content (0.01 to 0.20 mg GAE/mL), 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (0.10 to 3.22 mmol TE/mL), and ferric-ion reducing antioxidant power (0.49 to 3.31 μmol TE/mL) improved significantly. Elongation at break (46.53 % to 90.87 %) and thickness (0.08 mm to 0.17 mm) increased while tensile strength (11.62 MPa to 3.30 MPa) decreased after incorporating DSP. The films improved UV-shielding ability, although DSP affected water barrier properties (2.91 to 7.83 × 10^-10 g/m.s.Pa) and increased solubility and swelling rate. The performance of CsCNC bioactive film containing 4 % DSP for preserving veal meat during refrigeration for 8 days was studied. Compared to conventional cling film, the bioactive film retained meat quality by preserving pH, color, and lipid stability while delaying microbial spoilage. This study demonstrates the potential of valorizing both phenolic and cellulosic fractions from date seeds to develop an eco-friendly and bioactive packaging film.