In this study, a microcrystalline cellulose (MCC)-stabilized Pickering emulsion approach was developed to integrate hydrophobic natural deep eutectic solvents (NADES; menthol:decanoic acid, 1:1 molar ratio) into agar-based biopolymer films. MCC was evaluated not only as a filler but also as a functional interfacial component governing hydrophobic phase distribution and structural organization. SEM analysis showed that MCC concentration significantly influenced morphology; films with 0.2% MCC exhibited a more homogeneous structure, whereas 0.5% MCC led to heterogeneous and irregular formations. Mechanically, films with 0.2% MCC showed higher elongation at break (16.37%) compared to 0.5% MCC (9.86%), while tensile strength remained similar (2.75–2.78 MPa). Increased MCC content enhanced surface hydrophobicity, as indicated by higher contact angle values. The 0.5% MCC films exhibited high moisture content (85%) and water solubility (93%), attributed to increased free volume and structural irregularity. Swelling index exceeded 40% in 0.2% MCC films but decreased at higher MCC levels. HS-GC-MS analysis revealed temperature-dependent controlled release of menthol, with significant release at 50 °C compared to 25 °C. Antimicrobial tests demonstrated broad-spectrum activity (8.9–24.2 mm). These results highlight MCC as an effective stabilizer for hydrophobic NADES integration and support the potential of these films for active packaging applications.
Akal et al. (Wed,) studied this question.