Use of whey proteins for encapsulation and controlled delivery applications

Whey proteins can be used as hydrogels and nanoparticle systems for encapsulation and controlled delivery of bioactive compounds. Whey protein concentrate (WPC) hydrogels exhibited pH-sensitive swelling behavior with minimum swelling ratio near the isoelectric point (pI) of whey proteins (∼5.1). The controlled drug release behavior of WPC hydrogels was studied using caffeine as a model drug. Consistent with the swelling behavior, the release of encapsulated model drug from the hydrogels was slower when the pH was below pI than it was at pH above pI. The swelling and release behavior of the WPC hydrogels can be changed easily with different layers of alginate coating. Nanoparticles of about 60 nm average particle size were prepared with beta-lactoglobulin (BLG) using a desolvation method by preheating the BLG solution to 60 °C. The stability of the particles was investigated by degradation experiments at neutral and acidic conditions with and without proteolytic enzyme.