## 4 Conclusions  
This study explored the application of high-pressure homogenization (HPH) on the protein recovery from _A. pyrenoidosa_, protein modification, and emulsion homogenization. It was demonstrated that HPH treatment significantly increased the protein recovery yield while inducing modifications to the protein secondary structure by exposing the hydrophobic protein core. Structural changes caused by HPH led to protein concentrates (APPCs) with improved oil-holding capacity. Surface and interfacial tension values of APPCs were satisfactory for nanoemulsion preparation, comparable to conventional emulsifiers. Additionally, the use of HPH on emulsion homogenization led to emulsions with significantly lower mean droplet size (MDD) and polydispersity index (PDI) compared to those homogenized solely by high-speed homogenization. The developed emulsions presented great resistance to centrifugation and heating-cooling cycles. After 30 d of storage, a thin cream layer was observed on emulsion surfaces. The creaming index (CI) was significantly lower at 25 \({}^{\circ}\)C compared to 4 \({}^{\circ}\)C, and emulsions prepared with APPCs from HPH-treated biomass exhibited a lower CI than those made with APPCs from untreated biomass. Overall, HPH treatment proved to be an effective technology for all the steps of this study, including protein recovery, improvement in protein functional properties, and emulsion homogenization, establishing a concrete base for the scale up of this process due to follow. The future perspectives of this work include the application of APPCs in developing delivery systems for the encapsulation of sensitive food ingredients, such as carotenoids, with the goal of significantly reducing their deterioration rate during storage.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app15010131/s1](https://www.mdpi.com/article/10.3390/app15010131/s1)]([https://www.mdpi.com/article/10.3390/app15010131/s1](https://www.mdpi.com/article/10.3390/app15010131/s1)), Table S1: Images of nanoemulsions with proteins from untreated (CNT) and HPH-treated (600 bar for 1 pass (600/1) and 800 bar for 4 passes (800/1)) biomass for different oil content (2, 4, and 6% \(w/w\)) after 1, 4, and 6 centrifugation cycles, 1, 4, and 6 heating-cooling cycles, 1, 2, and 4 freeze-thaw cycles, and at time zero (0 d) and after 30 d of storage at 4, 12, and 25 \({}^{\circ}\)C.  
Conceptualization, A.K. and M.K.; methodology, A.K., M.K. and N.S.; validation, A.K., M.K. and N.S.; formal analysis, A.K., M.K. and N.S.; investigation, A.K., M.K. and N.S.; resources, P.T. and M.C.G.; data curation, A.K. and M.K.; writing--original draft preparation, A.K. and M.K.; writing--review and editing, M.C.G. and P.T.; visualization, A.K. and M.K.; supervision, M.C.G. and P.T.; project administration, P.T.; funding acquisition, P.T. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.  
The authors declare no conflicts of interest.