**4. Conclusions**

From the obtained results it appears that the application of crossflow MF using a membrane of 1.4 μm pore size, at 50 ◦C and TMP 1.5 bar, influences the ovine milk (0.4% fat) in a similar way to the bovine milk (0.3% fat). More specifically, the applied crossflow MF improved the microbial quality, but significantly reduced (*p* < 0.05) the protein content and, consequently, the total solids content of both the ovine and bovine permeate. In addition, crossflow MF influenced the distribution of casein fractions between permeate and retentate with αs1- and β-CN retention being more pronounced in the case of ovine milk. The activity of indigenous enzyme ALP followed the allocation of the fat content, while the activity of cathepsin D was not influenced. Regarding cheesemaking properties, the firmness of the curd made from the ovine feed milk did not differ from the curd made from the ovine permeate. It is concluded that crossflow MF under the studied conditions can be used as pre-treatment to improve the microbial quality of ovine milk prior to cheesemaking. However, further study is needed to optimize the conditions of crossflow MF processing for this kind of milk.

**Author Contributions:** Conceptualization, E.M.; Data curation, G.P. and E.M.; Formal analysis, G.P. and C.P.; Methodology, E.M. and G.M.; Project administration, E.M.; Writing—review & editing, E.M. All authors have read and agreed to the published version of the manuscript.

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

**Acknowledgments:** This study is dedicated to the memory of I. Kandarakis who introduced the membrane technology in our lab. Moreover, the authors would like to thank T. Paschos for the technical support on microfiltration plant and the Dairy Industry DELTA S.A. for milk analyses on Milkoscan and Fossomatic.

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