The use of hydrocolloids-based microparticles in the field of bioactives microencapsulation is an area of great interest and research. However, their industrial scale production and their application in food products holds many technological challenges. The objective of this study was to investigate the microencapsulation of tryptophan, used as model active, into alginate microparticles obtained using the fluid gel route, as an easy industrial method for their production. Several alginate fluid gels, loaded with different amounts of tryptophan, were produced and characterized by particle size, rheological properties and encapsulation efficiency, then in vitro release kinetics using a dialysis approach were studied. Although the produced materials were unable to highlight a correlation between operating parameters and release kinetics, alginate fluid gels showed the ability to slow down the release of the drug compared to a water solution of tryptophan. Obtained microspheres showed very small sizes, which makes them suitable for the enrichment and delivery of actives in food products.
Keywords: Fluid gel, rheological properties, encapsulation, industrial process, release kinetic.