## 4 Conclusions  
Results shown in this work indicate that is has been possible to obtain food packaging films with double-function, i.e., oxygen scavenging and aromatic by incorporating PB and PA in the formulations. The incorporation of PB (5 and 13 wt %) and PA (5 wt %) into LDPE by cast film extrusion slightly influenced thermal and mechanical properties of films when compared to neat LDPE. A plasticizing effect was confirmed because of the addition of PA and PB resulting in an increase in the ductility of the polymer and in a slight decrease in the thermal properties. However, all the obtained films were transparent, showing no statistical differences in relation to the optical properties in comparison with LDPE. Overall, these results indicate the technical feasibility of the developed materials for use in food packaging applications. Regarding the oxygen absorption capacity of the films, values of 4.4 mL for PE/PA/PB13 and 2.7 mL O2 g-1 film for PE/PA/PB5 formulations were obtained after 6 days. These values were achieved without the incorporation of a metal catalyst in the formulation but using an UV activation procedure. The incorporation of PB in 13 wt % into a LDPE matrix improved the PA retention, being this behavior attributed to the ability of PB in enhancing crosslinking of LDPE as the concentration of PB increased. The results suggested the potential of PE/PB/PB13 films as an oxygen scavenger and aromatic food packaging system to offer protection against lipid oxidation in nuts improving the consumer's experience avoiding the use of additives or additional packaging elements. A scale-up of this study including industrial processing extrusion techniques would be needed to obtain commercial materials based on these formulations. In addition, further work is needed to validate the developed materials in a real scenario, such as the use of this material to pack nuts and to study its impact in nut's shelf-life and organoleptic properties avoiding oxidation reactions and improving the customer's sensorial experience.  
Conceptualization, A.B.S.; S.E.M.P.; A.J.-P., A.M.T., C.S.R. and M.M.P.; methodology, A.B.S.; S.E.M.P.; M.M.P. and A.J.-P.; formal analysis, A.B.S.; A.J.-P. and S.E.M.P.; data curation, A.B.S.; A.J.-P.; A.M.T. and S.E.M.P.; writing--original draft preparation, A.B.S. and A.J.-P.; writing--review and editing, A.B.S.; S.E.M.P.; A.J.-P., A.M.T., C.S.R. and M.M.P.; Supervision: A.B.S.; S.E.M.P. and M.M.P. All authors have read and agreed to the published version of the manuscript.  
This research was funded by Generalitat Valenciana (FEDEGENT/2018/021) and the Packaging, Transport and Logistics Research Center (ITENE) (ITENE-18Y).  
Figure 5: Concentration (ppm) and retention capacity (%) of 2,3-DMP, 2,6-DMP and nonanal present in PE/PB-based films after processing. Different superscripts within the same compound for the different formulations indicate statistically significant different values (\(p<0.05\)). Different superscripts within the values of the sum of the individual retentions (%) of the main aroma compounds (i.e., 2,3-DMP, 2,6-DMP and nonanal) for the different formulations indicate statistically significant different values (\(p<0.05\)).