Spontaneous co-assembly of proteins for encapsulation of a hydrophilic vitamin

Encapsulation of bioactive compounds such as vitamins and micronutrients is a great challenge to develop new functional foods. There is a growing demand from consumers for food products offering health benefits such as products enriched with vitamins. At the same time, consumers tend to favor natural food or products with minimal amount of additives. The encapsulation of bioactives usually resorts to extraneous components that are not natural constituents of the targeted food product. It could therefore be relevant to seek to encapsulate bioactive molecules by means of intraneous components that are natural constituents of the targeted food product. Among food constituents, food proteins are biopolymers that appear suitable for the transport and protection of several bioactives. Recent studies have reported the ability of two oppositely charged milk proteins, beta-lactoglobulin (BLG) and lactoferrin (LF), to spontaneously co-assemble to form heteroprotein complexes called “coacervates” (Anema et al., 2014; Tavares et al., 2015). Complex coacervation is a well-known phase separation between two oppositely charged macromolecules, into a concentrated phase of coacervates and dilute phase. It can be used as an encapsulation technique. In the literature, two general procedures can be found to encapsulate a compound by the complex coacervation of two biopolymers. The objective of this work is to investigate the potentialities of coacervates entirely made from food proteins to encapsulate a bioactive compound according to these procedures. We investigated the potentiality of BLG-LF coacervates to encapsulate the hydrophilic vitamin B9