Coacervation technique as an encapsulation and delivery tool for hydrophobic biofunctional compounds

Coacervation between proteins and other polymers such as polyphosphates and polysaccharides is of interest for both research and industrial applications due to the increasing demands of the consumers for the food products prepared using natural ingredients. Consequently, coacervation technology has been investigated and used for the stabilization of susceptible biofunctional food ingredients against oxidation and/or degradation, with the benefit of masking undesired flavors and enhancing their controlled-release behavior. Compared with spray drying which is the most widely used microencapsulation technique, complex coacervation has advantages including high encapsulation efficiency (up to 99%), high loading of the "core" material (>50%) and significantly improved controlled-release characteristics. This chapter focuses on the utilization of coacervation techniques for encapsulating and stabilizing various oxidatively unstable biofunctional food ingredients. Discussion will center upon factors affecting the entire preparation of microencapsulation products, from the design of the delivery system, selection of the appropriate "shell" material to the crosslinking of the encapsulant. Characterization of the final microcapsules and applications of coacervation technology in the food industry will also be discussed.