Construction of Bletilla striata polysaccharide-coconut oil gel-like Pickering emulsions driven by depletion...

To overcome the inherent emulsifying limitations of Bletilla striata polysaccharides while preserving their bioactive activity, we developed DBSP-5-based gel-like Pickering emulsions combining plant-derived carboxylated cellulose nanocrystals (cCNC) and coconut oil, stabilized without surfactants to enable eco-friendly applications in biomedical and cosmetic formulations. While cCNC stabilized coconut oil into gel-like emulsions, water precipitation occurred after 7 days. A dual-layer stabilization strategy employed degraded Bletilla striata polysaccharides (DBSP)-5, leveraging its depletion effect to enhance cCNC adsorption onto droplets, reinforcing the flocculating network. The addition of DBSP-5 in ratios of 1:5, 2:5, and 1:1, emulsion droplets aggregated into gel-like structures. Rheological analysis showed DBSP-5 improved emulsion stability via depletion effects, augmented the emulsion structures and ionic stability, and exhibited effectiveness against temperature changes. Furthermore, emulsions with 1:5 and 2:5 ratios exhibited strong elastic recovery, indicating a reinforced three-dimensional cCNC-coconut oil network. This dual-layer approach enhances polysaccharide delivery potential by optimizing emulsion stability and gelation.