Natural emulsifiers — Biosurfactants, phospholipids, biopolymers, and colloidal particles: Molecular and physicochemical basis of functional performance

• Published in: Advances in colloid and interface science 2016-08, Vol.234, p.3-26
• Main Authors: McClements, David Julian, Gumus, Cansu Ekin
• Format: Article
• Language: English
• Subjects: Biological Products - chemistry; Biological Products - isolation & purification; Biopolymers - chemistry; Biosurfactants; Colloids; Cosmetics - chemistry; Emulsifiers; Emulsifying Agents - chemistry; Emulsions; Hydrogen-Ion Concentration; Nanoparticles - chemistry; Natural proteins; Osmolar Concentration; Particle Size; Phospholipids; Phospholipids - chemistry; Pickering stabilization; Polysaccharides; Polysaccharides - chemistry; Proteins - chemistry; Surface-Active Agents - chemistry; Temperature
• ISSN: 0001-8686; 1873-3727
• DOI: 10.1016/j.cis.2016.03.002

There is increasing consumer pressure for commercial products that are more natural, sustainable, and environmentally friendly, including foods, cosmetics, detergents, and personal care products. Industry has responded by trying to identify natural alternatives to synthetic functional ingredients within these products. The focus of this review article is on the replacement of synthetic surfactants with natural emulsifiers, such as amphiphilic proteins, polysaccharides, biosurfactants, phospholipids, and bioparticles. In particular, the physicochemical basis of emulsion formation and stabilization by natural emulsifiers is discussed, and the benefits and limitations of different natural emulsifiers are compared. Surface-active polysaccharides typically have to be used at relatively high levels to produce small droplets, but the droplets formed are highly resistant to environmental changes. Conversely, surface-active proteins are typically utilized at low levels, but the droplets formed are highly sensitive to changes in pH, ionic strength, and temperature. Certain phospholipids are capable of producing small oil droplets during homogenization, but again the droplets formed are highly sensitive to changes in environmental conditions. Biosurfactants (saponins) can be utilized at low levels to form fine oil droplets that remain stable over a range of environmental conditions. Some nature-derived nanoparticles (e.g., cellulose, chitosan, and starch) are effective at stabilizing emulsions containing relatively large oil droplets. Future research is encouraged to identify, isolate, purify, and characterize new types of natural emulsifier, and to test their efficacy in food, cosmetic, detergent, personal care, and other products. [Display omitted]