Encapsulation of stevia rebaudiana Bertoni aqueous crude extracts by ionic gelation – Effects of alginate blends and gelling solutions on the polyphenolic profile

[Display omitted] •Encapsulation of stevia crude extract within two alginate blends by ionic gelation has been assessed.•High encapsulation efficiency of polyphenols was achieved for all stevia-loaded beads.•Size of beads decreased as encapsulation efficiency increased for both the blends.•Metabolomics profiling identified 479 free and encapsulated polyphenolic compounds.•Crosslinking conditions impacted on phenolic profile providing a selective uptake. We formulated and characterised two alginate blends for the encapsulation of stevia extract (SE) via ionic gelation through an extrusion technique. Calcium chloride in SE and calcium chloride solutions were assessed as crosslinkers to overcome phenolic losses by diffusion and increase encapsulation efficiency (EE). Regardless of the blend, all stevia-loaded beads exhibited high EE (62.7–101.0%). The size of the beads decreased as EE increased. Fourier transform infrared analysis showed increased hydrogen bonding between SE and alginates, confirming the successful incorporation of SE within the matrix. Untargeted metabolomics profiling identified 479 free and encapsulated polyphenolic compounds. Flavonoids (catechin and luteolin equivalents) were predominant in SE whereas tyrosols and 5-pentadecylresorcinol equivalents were predominant in all bead formulations. Three-common discriminant compounds were exclusive to each blend and were inversely affected by the crosslinking conditions. Both alginate blends have been shown to be feasible as carrier systems of stevia extracts independent of crosslinking conditions.