**4. Conclusions**

The enrichment of mayonnaise with OLE-loaded microparticles (Mayo + Alg/Pec) was effective in improving its physical properties in terms of both the dispersion degree of the oil droplets and lubricant properties of the emulsions; however, the highest viscosity, which in turn was reflected by the lowest spreadability, led to a different sensory perception with respect to both the control and Mayo + OLE samples. The addition of OLE, either as pure extract or encapsulated in alginate/pectin microparticles, slightly affected the chromatic parameters with respect to the control sample. The sensory evaluation depicted a lower overall acceptability for both of the enriched samples, likely due to the increased salty and bitter perception. The encapsulation technique adopted was thus not able to mask or control the bitterness perception, leading to the conclusion that further investigations are needed in terms of encapsulation methods, bead compositions and structures, and mayonnaise formulations to overcome such issues. The proposed research could represent a valid contribution in the wide panorama of functional foods and opens new opportunities for formulating healthier foodstuffs while valorizing olive by-products.

**Author Contributions:** Conceptualization, F.F. and C.D.D.M.; formal analysis, F.F., G.S., and C.D.D.M.; investigation, F.F.; resources, C.D.D.M. and L.N.; data curation, F.F., L.N., G.S., and C.D.D.M.; writing—original draft preparation, F.F.; writing—review and editing, C.D.D.M., P.P., and D.M.; visualization, C.D.D.M.; supervision, C.D.D.M., D.M., and P.P.; funding acquisition, C.D.D.M.; project administration, C.D.D.M. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was supported by AGER 2 Project–"S.O.S—Sustainability of the Olive-Oil System"—grant no. 2016-0105.

**Acknowledgments:** The authors are grateful to Domenico Cifà from Oleafit srl (Isola del Gran Sasso, Teramo, Italy) for providing the olive leaf extract and Chiara Di Giacinto for her contribution to this work.

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