Microencapsulation of a whey protein hydrolysate within micro-hydrogels: Impact on gastrointestinal stability and potential for functional yoghurt development

Gelatin and chitosan micro-hydrogels containing a potentially bioactive whey protein hydrolysate were developed through spray drying and the impact of microencapsulation on protection during digestion and peptide stability against lactic acid fermentation during yoghurt manufacturing was assessed. The results showed that the protection exerted by the encapsulation structures during milk fermentation was sequence- and matrix-dependent, being chitosan more effective than gelatin in stabilising the peptides. However, only 5 out of the 21 fermentation-susceptible peptides identified could be protected through encapsulation within chitosan (1 of which was also protected by gelatin). Moreover, the encapsulation within chitosan microparticles did not substantially affect the peptide profile of the digested hydrolysate, and therefore, the peptide bioaccessibility was not expected to be compromised.