Parameters affecting calcium-alginate bead characteristics: Viscosity of hydrocolloids and water solubility of core material

Abstract

In this study, calcium-alginate beads were produced and characterized by ionic gelation technique using three different copolymers (gum arabic (GA), kappa-carrageenan (CG), guar gum (GG)), and seven different phenolic compounds (tannic acid, chlorogenic acid, gallic acid, p-coumaric acid, caffeic acid, naringin, and hesperidin). The effect of the viscosity of copolymer and water solubility of the phenolic compound on the size, shape, swelling, encapsulation efficiency (EE), loading capacity (LC), and production yield (PY) of the beads were investigated. In addition, the impact of the core material concentration in the calcium chloride solution on the EE was determined. The bead sizes increased by 6.8, 11.4, and 35.3 %, respectively, with the use of GA, CG, and GG. The EE of the beads ranged from 28.36 to 89.30 % and increased with increasing copolymer viscosity and decreasing water solubility of the phenolic compound. When the core material concentration difference between the alginate and calcium chloride solutions was reduced to zero, the EE of the gallic acid bead increased from 32.95 % to 89.05 %. The results of this study show that copolymer viscosity, the water solubility of core material, and the core material concentration difference between alginate and calcium solutions should be considered in ionic gelation applications.