Encapsulation of bitter peptides in water-in-oil high internal phase emulsions reduces their bitterness and improves gastrointestinal stability

Many peptides exhibit beneficial physiological functions, but their application in foods is limited because of their undesirable taste and their tendency to degrade when exposed to gastrointestinal conditions. In this study, water-in-oil high internal phase emulsions (W/O HIPEs) were used to encapsulate bitter peptides. A combination of confocal fluorescence and electron microscopy was used to confirm the formation of W/O HIPEs. The presence of high concentrations of bitter peptides increased the apparent shear viscosity, shear modulus and sedimentation stability. They also improved the oxidative stability of the HIPEs. Electronic-tongue and sensory analysis showed that encapsulated peptides within the HIPEs substantially reduced their bitterness. Moreover, a simulated gastrointestinal study showed that W/O HIPEs protected peptides from being released in the stomach. Our results show that W/O HIPEs can be used to mask the bitterness and improve the gastrointestinal stability of peptides, which may increase their utilization as bioactive ingredients in foods.