Antimicrobial and antioxidant AIE chitosan-based films incorporating a Pickering emulsion of lemon myrtle (Backhousia citriodora) essential oil

Films based on chitosan (CS) and Lemon Myrtle (Backhousia citriodora) essential oil (LEO) were prepared that exhibited novel dose-dependent fluorescent patterns owing to aggregation-induced emission (AIE) effects. Specifically, chitosan-coated alkali lignin ([email protected]) colloid particles were obtained by a facile one-pot ultrasonication, and were used to prepare LEO-loaded Pickering emulsions ([email protected]). Different amounts of [email protected] were incorporated into CS-based film-forming solutions. The composite ([email protected]) films contained LEO/CS (w/w) ratios around 0%, 5.9%, 14.8%, 29.6% and 59.2% after solution casting. The microstructures, optical properties, water affinity, mechanical attributes, fluorescent characteristics, as well as antimicrobial and antioxidant efficacies of [email protected] films were assessed for multifunctional food packaging. 0.5% (w/v) of [email protected] particles (pH ∼4.3 to 4.6) enabled stabilization of [email protected] (φ = 0.4) for at least 35 days. Adding [email protected] with appropriate LEO/CS (w/w) ratios modified the properties of the composite films. The [email protected] film (with LEO/CS (w/w) around 29.6%) was the most promising candidate for multifunctional packaging considering its optimal optical properties, resistance to moisture and mechanical stress, characteristic fluorescent attributes along with antimicrobial and antioxidant activities.