Incorporation of Oregano Essential Oil Microcapsules in Starch-Poly (Butylene Adipate Co-Terephthalate) (PBAT) Films

Cassava starch and poly(butylene adipate-co-terephthalate) (PBAT) based films containing microencapsulated oregano essential oil (OEO) and free OEO are produced by blow extrusion. Microcapsules produced by ionic gelation were characterized with respect to average size, morphology, and encapsulation efficiency. The microcapsules were spherical and ranged in size from 20 to 1000 mu m. Encapsulation efficiency (EE) is 83%. The films are analyzed in terms of their morphology, mechanical properties, water vapor permeability (WVP) and antibacterial properties. The films containing OEO microcapsules exhibited lower ultimate tensile strength, Young's modulus and elongation at break than the control films and the films containing free OEO. The WVP of films containing free OEO is slightly lower, while that of films containing microencapsulated OEO did not differ significantly from the control films. Scanning electron microscopy (SEM) images showed that the surface of films containing microencapsulated OEO are less homogeneous than those of the control and free OEO films. Films containing free or microencapsulated OEO presented inhibitory activity against Staphylococcus aureus, but not against Escherichia coli.