Whey protein peptides as components of nanoemulsions: A review of emulsifying and biological functionalities

•Nanoemulsions are a nanotechnology with food applications.•Whey protein peptides are potential emulsifiers in food nanoemulsions.•Bioactive peptides may act as functional and nutraceuticals agents.•Peptides serve a dual-functional role in foods as emulsifiers and bioactive compounds when consumed.•Nanoemulsions are delivery vehicles for bioactive peptides and compounds.

Milk proteins are used to make emulsions, and may be used to make nanoemulsions. Nanoemulsions are a nanotechnology with food applications, and possess superior physicochemical and sensorial properties compared to macro- and microemulsions. They are also able to deliver bioactive compounds when consumed. In this review, three aspects of food nanoemulsions will be examined: (1) the production and properties of food nanoemulsions, (2) emulsifiers/surfactant (ionic, non-ionic, phospholipid, polysaccharide, and protein) used in nanoemulsions production. The suitability of proteins and protein hydrolysates as nanoemulsifiers is discussed, with a particular focus on whey protein, (3) the potential of whey protein derived peptides as both emulsifiers and bioactive compounds in nanoemulsion delivery systems. Lastly, the potential delivery of bioactive peptides and other bioactive compounds within nanoemulsion systems is also discussed.