**4. Conclusions**

The mechanical properties of the films were affected depending on the concentration of EA, which was beneficial, because depending on the potential applications could adapt the mechanical properties. Incorporating EA promoted increases in opacity. This indicated that the films could be efficient in preventing the passage of UV light. The results of this study suggest that films based on apple starch added with ellagic acid (a nutraceutical agent with powerful antioxidant action) can be used for the development of active food packaging. Finally, it is necessary to explore strategies that increase the solubility of ellagic acid in the filmogenic solution and improve its incorporation in thermoplastic starch.

**Author Contributions:** Investigation and writing–original draft, J.M.T-G.; Methodology, J.d.J.O.-P., C.R.-V., G.I.O.O, M.A.A.-G. and D.L.-G.; Project administration, P.B.Z.-F.; Validation, H.Y.L.-D.l.P.; Visualization, F.H.-C.; Writing–original draft, M.E.-D. and M.H.-G.; Writing–review & editing, R.B.-J. and J.J.B.-F.

**Funding:** This study is supported by CONACYT-Mexico and the Research Center for Food and Development (CIAD, A.C.).

**Acknowledgments:** The first author, J.M. Tirado-Gallegos thanks the National Council of Science and Technology (CONACYT) of Mexico for the scholarship granted to carry out doctoral studies at the "Centro de Investigación en Alimentación y Desarrollo (CIAD), A.C., Unidad Cuauhtémoc." The authors thank Emilio Ochoa Reyes for their technical assistance. This study is the product of the Research Group in Carbohydrates, Packaging and Functional Foods (CEAF) of CIAD-Cuauhtemoc, Chihuahua, Mexico led by Paul Baruk Zamudio-Flores.

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