EUBCE 2026 - Rudolfs BERZINS - Birch Outer Bark-Derived Betulin Hydrogels as Sustainable Feedstock for Pickering Emulsions

Birch Outer Bark-Derived Betulin Hydrogels as Sustainable Feedstock for Pickering Emulsions

Short Introductive summary

In this study, particles derived from birch outer bark extractives were used to formulate Pickering emulsions as a potential ecological cosmetic cream base. Two types of extractive particles were evaluated – purified (99.4 wt% triterpenes) and unpurified (72 wt% triterpenes, 1.4 wt% polyphenols). Using a hydrogel-based-sizereduction method, the average particle size was decreased from 1373 to 205.4 nm for unpurified and from 1080 to 230.9 nm for purified particles. Both particle types were polydisperse (polydispersity index was 0.2-0.25) and negatively charged, indicating their suitability for stabilizing water-in-oil emulsion. Emulsion performance was assessed through storage modulus (G’) in the linear viscoelastic region and thermal stability after 3 days at 50 oC. The highest G’ values were obtained for emulsions containing 60% water and 2.2 wt% unpurified (G’ = 11.5 kPa) and purified (G’ = 23.1 kPa) particles. Additionally, optical microscopy results indicated that slow coalescence does occur in all systems. As an additional benefit, emulsions stabilized with unpurified particles exhibited a threefold increase in oil?phase oxidative stability due to the presence of polyphenols.

R. Berzins, Latvian State Institute of Wood Chemistry, Riga, LATVIA
S. Vitolina, Latvian StatLatvian State Institute of Wood Chemistrye Institute of Wood Chemistry, Riga, LATVIA
A. Paze, Latvian State Institute of Wood Chemistry, Riga, LATVIA
D. Godina, Latvian State Institute of Wood Chemistry, Riga, LATVIA
J. Rizikovs, Latvian State Institute of Wood Chemistry, Riga, LATVIA
L. Brunina, SIA Labrains, Riga, LATVIA
A.R. Feldmanis, AS Latvijas Finieris, Riga, LATVIA
L.K. Berzina, AS Latvijas Finieris, Riga, LATVIA