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.

1. Plastic pollution is a major environmental problem today, threatening land, marine, and freshwater ecosystems [1]. The excess of plastic waste in the environment is directly related to the preva...

The present study compared the effectiveness of methanol and two choline chloride-based deep eutectic solvent systems containing lactic acid and citric acid for the extraction of phenolic compounds from Aronia melanocarpa. Extraction was performed under previously optimized conditions using a solid-to-liquid ratio of 1:20, an extraction temperature of 50 °C, and an extraction time of 60 minute. The phenolic composition of the extracts was determined by liquid chromatography coupled with high-resolution mass spectrometry. Antioxidant activity was evaluated by free radical scavenging and reducing power assays, while antimicrobial activity was assessed against nine bacterial strains and Candida albicans using the agar well diffusion method. The solvent system markedly influenced the phenolic and flavonoid composition of the extracts. The methanol extract contained the highest levels of chlorogenic acid (19,441.85 µg/g extract), quinic acid (433,957.67 µg/g extract), and isoquercitrin (16,010.96 µg/g extract). In contrast, the citric acid-based deep eutectic solvent extract was enriched in quercetin (2,649.73 µg/g extract), isorhamnetin (125.77 µg/g extract), narcissin (270.01 µg/g extract), liquiritigenin (1,383.35 µg/g extract), and phloridzin (437.59 µg/g extract). The lactic acid-based deep eutectic solvent extract exhibited the strongest free radical scavenging activity, with IC₅₀ values of 16.54 and 35.16 µg/mL, and also showed the highest cupric ion reducing antioxidant capacity. In contrast, the methanol extract demonstrated the greatest ferric ion reducing capacity. The citric acid-based deep eutectic solvent extract produced the largest inhibition zones against most of the tested microorganisms. These findings demonstrate that deep eutectic solvent composition determines not only the phenolic and flavonoid profile of Aronia melanocarpa extracts but also their dominant antioxidant mechanism and antimicrobial effectiveness, highlighting the potential of solvent-directed extraction for obtaining extracts with targeted biological properties.