The awareness of sustainability approaches has focused attention on replacing synthetic emulsifiers with natural alternatives when formulating nanoemulsions. In this context, a comprehensive review of the different types of saponins being successfully used to form and stabilize nanoemulsions is presented, highlighting the most common natural sources and biosynthetic routes. Processes for their extraction and purification are also reviewed altogether with the recent advances for their characterization. Concerning the preparation of the nanoemulsions containing saponins, the focus has been initially given to screening methods, lipid phase used, and production procedures, but their characterization and delivery systems explored are also discussed. Most experimental outcomes showed that the saponins present high performance, but the challenges associated with the saponins’ broader application, mainly the standardization for industrial use, are identified. Future perspectives report, among others, the emerging biotechnological processes and the use of byproducts in a circular economy context.
This work was financially supported by Base Funding − UIDB/00690/2020 of CIMO − Centro de Investigação de Montanha funded by national funds through FCT/MCTES (PIDDAC), Funding UIDB/50020/2020 and UIDP/50020/2020 of LSRE-LCM funded by national funds through FCT/ MCTES (PIDDAC), and project AIProc-Mat@N2020 − NORTE-01-0145-FEDER 000006 supported by NORTE 2020 under the Portugal 2020 Partnership Agreement, through ERDF. T.B.S. thanks FCT and European Social Fund (ESF) for the Ph.D. grant (2020.05564.BD).
