Interest of Pickering Emulsions for Sustainable Micro/Nanocellulose in Food and Cosmetic Applications

Abstract

In the present review, natural and non-toxic particles made of micro/nanocellulose were specifically targeted as stabilizers of emulsions located at dispersed and continuous phases interfaces (called Pickering Emulsions, PEs). PEs are biphasic systems stabilized by solid particles with a recent interest in food and cosmetic domains. PEs have been more and more studied in the last ten years due to their advantages compared to conventional emulsions with surfactants. PEs have already been stabilized with various types of particles and particularly cellulose. Even if some studies showed that PEs were more stable when cellulose was chemically modified, numerous other recent studies showed that unmodified micro/nanocellulose is also promising biomaterial to stabilize PEs. Micro/nanocelluloses can be extracted by various green processes from numerous agricultural wastes and co-products, as banana peels, corncob, ginkgo seed shells, lime residues, mangosteen rind, oil palm empty fruit bunches, pistachio shells, as well as wheat straw. Main green processes used to treat cellulose are grinding, high pressure homogenization, microfluidization, enzymatic hydrolysis, subcritical water, extrusion, electron beam irradiation, cryocrushing, microwaves or sonication. PEs formulated with cellulose clearly participate to a global sustainable development but, additional studies will be necessary to better understand PEs stability and improve properties.

Pickering Emulsions: A Novel Tool for Cosmetic Formulators

“…Thus, by tuning the volume fractions of the two liquids, it is possible to switch emulsions stabilized with hydrophilic particles from O/W emulsions to W/O one. A similar transition can occur for hydrophobic particles (in this case, the transition occurs from W/O emulsions to O/W emulsions) [32].…”

Progress in the Application of Food-Grade Emulsions

“…In addition, they have been applied to enhance the stabilization and paper sizing performance of various materials [ 351 ], to prepare self-healing composite coatings [ 352 ], and to limit the influx of metal ions [ 353 ]. Additionally, they can be used in cosmetic applications [ 354 ], such as in the case of a nanoemulgel that employs Argania spinosa microfibrillated cellulose and natural emulsifiers [ 355 ]. In further works, the application of emulsions in cosmetics should focus on formulation to ensure the desired level of skin penetration and the corresponding risk assessments [ 356 ].…”

Review of High-Frequency Ultrasounds Emulsification Methods and Oil/Water Interfacial Organization in Absence of any Kind of Stabilizer

“…Limiting stabilizers’ use or replacing chemical stabilizers by green and natural biomolecules, such as glycolipids, lipopeptides, as well as phospholipids, is challenging because it is difficult to obtain them at the industrial scale [ 12 ]. Pickering emulsions formulation with natural particles [ 16 , 17 , 18 ], as well as emulsifier-free emulsion formulation [ 2 ], i.e., emulsions formulated in absence of any stabilizers, such as proteins, polysaccharides, lipid-derived molecules, particles [ 6 , 8 ] represent other alternatives.…”