**4. Conclusions**

This works demonstrated that active packaging based on selenium nanoparticles prevents the oxidation of real food and enhances and extends its shelf-life. The presence of nanoSe in the multilayer did not increase the barrier properties for hexanal and aldehydes, but its performance as a strong free radical scavenger was demonstrated. Several industrial lines and food companies tested the material for a wide series of food, and in all cases considerable improvement of food protection versus oxidation was found. This is the first time that the efficiency of an active antioxidant material was demonstrated at industrial scale. In addition, it was demonstrated that the combination of the TBARS method with tasting (for ready-to-eat foods) were the most suitable methodology to evaluate the efficiency of the antioxidant packaging containing nanoSe. This study opens the door to new developments of active materials containing nanoparticles in which the nanoparticles are not in direct contact with the food, but act on food protection from the packaging.

**Author Contributions:** P.V. did the chemical analysis of fatty Acids Oxidation Study, hexanal and TBARS. E.C. prepared the laminates at lab scale and organized and processed the data from organoleptic study. C.N. designed and supervised the study both lamination, chemical, SEM and sensory analysis.

**Funding:** This research was funded by Gobierno de Aragón and Fondo Social Europeo, Grant T53\_17R.

**Acknowledgments:** Thanks are given to Gobierno de Aragón and Fondo Social Europeo, Grant T53\_17R for the financial help given to GUIA group.

**Conflicts of Interest:** The authors declare no conflict of interest.
