*2.1. Reagents*

Polydimethylsiloxane (PDMS)—Sylgard® 184 Silicone Elastomer was obtained from Dow Corning (Midland, MI, USA). Zein from maize (CAS Number: 9010-66-6), presenting a molecular weight of 22–24 kDa, was supplied by Sigma-Aldrich (Saint Louis, MO, USA). Glycerol (anhydrous extra pure) was purchased from Merck (Darmstadt, Germany). The licorice EO (*Glycyrrhiza glabra* L.) (*Leguminosae*/*Fabaceae*) was obtained from Best Formula Industries (BF1, Kuala Lumpur, Malaysia). The EO (Pure Essential) was isolated from trunks of the plant by steam distillation and was stored at −20 ◦C in the dark until analysis and further use. The purity of the EO was tested and its quality ensured to be consistent with the standards described in the European Pharmacopoeia, being suitable to be used in products for human consumption. The chemical composition, analyzed by Gas Chromatography coupled to Mass Spectrometry (GC-MS, Perkin Elmer Clarus 600, Shelton, CT, USA), and the bioactivities, namely antioxidant ant antibacterial, of this EO were previously published [13].
