Microencapsulation and controlled release of α-tocopherol by complex coacervation between pea protein and tragacanth gum: A comparative study with arabic and tara gums

Abstract

The ability of pea protein isolates (PPI) to form complex coacervates with tragacanth gum (TRAG) was used for the microencapsulation of α-tocopherol mixture with pH-dependent release properties. The microcapsules were compared to three other models: PPI alone, PPI and gum arabic (PPI-GAC, known to form microcapsules of complex coacervates), and PPI and tara gum (PPI-TARA, non-ionic polysaccharides). The behaviors of the complex coacervates and microcapsules were studied according to the protein/polysaccharide mixture and protein/polysaccharide ratio. The formation of complex coacervates from the PPI-TRAG and PPI-GAC mixtures impacted the particle size of the liquid suspensions and microcapsules, the efficiency of encapsulation and the active release profile. An interesting gastroprotective behavior was identified for the PPI-TRAG mixture at the 1:1 ratio in simulated digestion media. Overall, the results showed the ability of PPI associated with polysaccharides to form microcapsules with a pH-dependent release behavior, that is promising in the field of gastroprotective microencapsulation.