**4. Conclusions**

The incorporation of SUN as an animal fat replacer in frankfurters offers interesting possibilities for the valorisation of sunflower oil by-products. SUN addition led to several nutritional improvements, including the lipid content (qualitative and quantitative), an increase in protein and minerals. SUN inclusion in frankfurters also promoted the presence of phenolic compounds, mostly phenolic acids. Frankfurters with SUN could benefit from several on-pack nutrition and health claims. Although the reformulation process using SUN as animal fat replacer resulted in some changes in the technological and structural characteristics of the products, the products were found acceptable from a technological point of view. Further sensory tests with a larger consumers' sample will be needed to build onto the preliminary results from the pilot sensory study here reported. In the future, SUN could also be used as an animal fat alternative in plant-based meat substitutes or cell-cultured meat products as part of an effort to replace animal products and have a positive impact on animal welfare and the environment.

**Author Contributions:** Conceptualization, S.G., T.P., C.R.-C., and A.M.H.; data curation, S.G., T.P., J.P.-J., and A.M.H.; formal analysis, S.G., T.P., J.P.-J., and A.M.H.; funding acquisition, C.R.-C., and A.M.H.; investigation, S.G., T.P., C.R.-C., and A.M.H.; methodology, S.G., T.P., J.P.-J., C.R.-C., and A.M.H.; project administration, C.R.-C., and A.M.H.; resources, C.R.-C., and A.M.H.; supervision, C.R.-C; validation, J.P.-J; visualization, A.M.H.; writing—Original draft, S.G., T.P., J.P.-J., C.R.-C., and A.M.H.; writing—Review and editing, S.G., T.P., J.P.-J., C.R.-C., and A.M.H. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the CSIC Intramural project (grant number 201470E073) and CYTED (grant number reference 119RT0568; HealthyMeat network). Anastasia Palatzidi was the recipient of an Erasmus+ fellowship and of an EIT Food RIS Fellowship 2019—funded by the European Institute of Innovation and Technology, a body of the European Union. Simona Grasso was a recipient of a travel bursary from the Institute of Food, Nutrition and Health at the University of Reading.

**Acknowledgments:** Andrea Sánchez-Monedero and Anastasia Palatzidi are acknowledged for technical assistance during polyphenols and dietary fibre analyses, respectively. We are grateful to the ICTAN Analysis Services Unit for providing facilities for chromatography analysis and in particular to Inmaculada Álvarez-Acero for technical assistance. The authors are grateful to the company Planetarians for donating the defatted sunflower seed flour.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
