Fabrication and characterization of phycocyanin-alginate-pregelatinized corn starch composite gel beads: Effects of carriers on kinetic stability of phycocyanin

Abstract

Composite gel beads using calcium alginate and different concentrations of pregelatinized corn starch (PCS) were produced to encapsulate phycocyanin (PC). Rheological properties of different sodium alginate/PCS/PC mixtures, structural and morphological properties of beads, and kinetic stability of encapsulated PC (upon heating at various time-temperature combinations) were then assessed. Rheological properties of the mixtures exhibited shear thinning behaviors. Aquagram revealed that the PC-containing beads had more water structure with weak‑hydrogen bonds. Morphological images represented less subsidence in the structures of composite gel beads, unlike PCS-free beads. Kinetic study showed that degradation rate constant values of PC encapsulated in composite gel beads (1.08–3.45 × 10−4, 3.38–4.43 × 10−4, and 5.57–15.32 × 10−4 s−1) were lower than those in PCS-free alginate gel beads (4.45 × 10−4, 9.20 × 10−4, and 18.04 × 10−4 s−1) at 40, 50, and 60 °C, respectively. This study suggests that the composite gel beads can improve PC stability.