Agar-based bioactive-composite packaging films reinforced with lignin-containing cellulose (LCC) and enriched with date seed bioactives extracted using choline chloride–urea deep eutectic solvent

Bioactive packaging material was developed by reinforcing lignin-containing cellulose fraction (LCC) and bioactive components from date seed powder (BC-DSP) into agar-carboxymethyl cellulose (A/CMC) and agar-chitosan (A/CS) composite films. Deep eutectic solvent (DES) mediated microwave-assisted extraction (MAE) was used to extract LCC and BC-DSP from defatted DSP of the Khalas variety. The reinforcing effect of the LCC (30.13 ± 0.008% cellulose, 14.4 ± 0.017% lignin, and 21.55 ± 0.01% hemicellulose) was investigated in A/CMC and A/CS films. Significant changes in the intermolecular interactions were observed in films through ATR-FTIR and XRD. The LCC reinforced films demonstrated an increase in tensile strength (TS) of 207.1 ± 0.72 MPa and 85.03 ± 0.31 MPa for A/CS and A/CMC, respectively. Moisture content was high in the reinforced A/CS (25.79 ± 0.21%) compared to the A/CMC (16.73 ± 0.6%). The addition of BC-DSP (1-7 wt%) increased the moisture content in both composites. The WVP, swelling index, color, and light barrier properties were significantly influenced by the distinct intermolecular interactions in the composite due to CMC and CS. Bioactive films showed antimicrobial activity for Staphylococcus aureus and Salmonella typhi. The soil burial test indicated that the agar-composite films degraded in 21 days, while the commercial film remained intact. The application study on cherry tomatoes showed that color, texture, and weight loss were affected by the type of coating (seal cover vs dip coat) and the composition.