Lemon verbena (Aloysia citriodora) essential oil: Physicochemical characterization, microencapsulation, and application in starch-based bioplastics

• Lemon verbena essential oil exhibited strong antioxidant and antimicrobial activity. • Microencapsulation was optimized at 194 °C and a 5:1 EO-to-dextrin ratio. • Microparticles showed high encapsulation efficiency (78%) and thermal stability. • Incorporation into starch-based bioplastic improved elasticity, UV resistance, and surface morphology. • Microcapsules are promising additives for biodegradable, active food packaging. The essential oil (EO) of lemon verbena ( Aloysia citriodora ) is recognized for its antioxidant and antimicrobial properties but is limited by its instability in direct applications. This study characterized the EO's chemical profile, identifying trans-verbenol (19.24 %), citronellal (17.11 %), and menthol (13.13 %) as major constituents. The EO exhibited strong bioactivity, including high DPPH radical scavenging activity (89.35 ± 1.85 %), antioxidant capacity (35.95 ± 0.76 mg Trolox mL⁻¹), and total phenolic content (14.93 ± 0.06 mg GAE mL⁻¹), with notable antimicrobial effects against Staphylococcus aureus, Enterococcus faecalis, and Botrytis cinerea. Microencapsulation by spray drying using dextrin and soy lecithin was optimized, achieving 78 % encapsulation efficiency at 194 °C and a 5:1 EO-to-dextrin ratio. The resulting microparticles exhibited low moisture (5.10 ± 0.59 %), high solubility (89.64 ± 0.05 %), uniform morphology, and thermal stability (onset 148.3 ± 1.23 °C, peak temperature 150.2 ± 2.35 °C, endset 160.3 ± 2.03 °C, ΔH −11.4 ± 0.85 J/g). When incorporated into starch-based bioplastic films, the EO microparticles induced visually perceptible color changes (∆E > 6), improved flexibility (up to 83.76 % elongation at break), and enhanced UV-barrier capacity (notably in the 200–300 nm range), while maintaining moderate water vapor permeability and mechanical integrity. Surface and cross-sectional SEM images revealed increased roughness and porosity with MEO inclusion, while FTIR spectra indicated molecular-level interactions via hydrogen bonding. These findings support the potential of lemon verbena EO microparticles as a bioactive ingredient in biodegradable packaging materials, with promising applications in food preservation systems through antioxidant and antifungal effects.