**7. Conclusions**

The use of fermentation/biotransformation to obtain high-added value compounds is a valuable solution to improve the reutilization of pomaces from the food industry. The advances in incorporating and optimizing the use of pomaces in animal feed by generating silages and feeds that improve animal health is a relevant alternative to using fermented pomaces. Growth performance can be affected, whereas animal health status can be improved. The absence of negative effects and the improvement in the nutritional quality of the foods obtained from animals fed with fermented pomaces is another favorable characteristic to support this strategy.

In terms of industrial processes, the production of high-added value products (especially from grape, apple, and olive) such as enzymes and organic acids for application in food processing as well as in other areas is a relevant application. The release of bound phenolics for the development of functional foods (supported by studies in vitro and in vivo), the synthesis of carotenes and fatty acids, and the production of volatile compounds to improve the aroma of food products are potential applications.

One of the main limitations in terms of industrial application consists of its current poor incorporation into other processing chains. Extraction and purification technologies can be seen as current bottlenecks to strengthening the connections between the pomace generation in food industries and their incorporation into other productions chains. In this sense, further studies could aim to explore strategies to improve the isolation of high-added value compounds. Additional studies are still necessary to define strategies to apply the high-added value compounds obtained from pomaces from fermentation/biotransformation in the development of food products. Studies about the detoxification and reduction of potential health risks associated with mycotoxins and pesticides are necessary.

**Author Contributions:** Conceptualization, P.E.S.M., M.P., R.D. and J.M.L.; writing—original draft preparation, P.E.S.M., M.P. and R.D.; writing—review and editing, M.P., R.D., A.N., C.H. and N.W.; supervision, J.M.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Acknowledgments:** Thanks to GAIN (Axencia Galega de Innovación) for supporting this publication (grant number IN607A2019/01).

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