Preparation of polymeric films. Two different types of zein films were prepared. A 80% hydroalcoholic solution containing 15% weight of zein was first prepared. Two fractions were separated: to the first one 0.125 g Carvacrol@MIL-100(Fe) composite was added per g of zein, whereas the corresponding amount of carvacrol was directly added in a concentration of 0.05 g/g zein to the second fraction. The mixtures were spread on a flat surface of PTFE using a 200 µm coating rod and dried in an open oven at 75 °C for 10 min. The films obtained were stored in PP/met envelopes until further characterisation. The residual content of carvacrol in both films was analysed. For this, samples were cut from both films, introduced into a micro vial, and tested by thermal desorption and gas chromatography obtaining a final concentration of carvacrol of 0.059 ± 0.008 g/g in the encapsulated film and 0.050 ± 0.001 g/g in the film with pure carvacrol.