Encapsulation of bitter peptides in diphasic gel double emulsions: Bitterness masking, sustained release and digestion stability

Bitter peptides (BP) have been reported to exhibit beneficial physiological activities, but their bitter taste and digestive sensitivity currently limits their application in foods. In this study, W1/O/W2 double emulsions were prepared with bitter peptides in the inner water phase. The effects of gelling the inner and/or outer water phases, as well as crystallizing the oil phase, were then investigated. Aqueous phase gelation reduced the particle size of the double emulsions, improved their physical stability, increased their encapsulation efficiency for the bitter peptides, and reduced the bitterness of the peptides. After simulated oral and gastric digestion, the bitter peptide-loaded W1/O droplets in the double emulsions retained their structure, thereby preventing release of the peptides in the mouth and stomach. Our results suggest that gelled double emulsions may have great potential to create more palatable functional foods containing bitter peptides.