Aerosol-Assisted Plasma Deposition of Quercetin-Containing Coatings for Active Packaging Applications

Quercetin (QC)-containing coatings were prepared by aerosol-assisted atmospheric-pressure plasma deposition employing two distinct strategies. In the first approach, QC was deposited by solution drop casting, followed by the deposition of a plasma-deposited barrier layer; in the second, the active compound was directly incorporated into the coating via plasma deposition from a quercetin-based aerosol feed. The two deposition strategies were comparatively evaluated in terms of chemical composition and surface morphology. The effects of QC concentration in the drop-cast or in the aerosol precursor solutions and of the thickness of the coating were investigated on the film composition and antioxidant performances. Both strategies led to the incorporation of quercetin in the final coating. HPLC and DPPH assays revealed that plasma exposure degrades QC, but the bilayer approach preserves up to 30% of its antioxidant activity. These findings pave the way for the scalable, solvent-free fabrication of bioactive coatings.