Effect of the weight ratio of alginate-modified tapioca starch on the physicochemical properties and release kinetics of chlorogenic acid containing beads

Sodium alginate (SA)-modified tapioca starch (TS) solutions (RSA/TS) in different weight ratios (1/0, 0.75/0.25, 0.5/0.5 and 0.25/0.75), added with chlorogenic acid (CGA), were dripped into CaCl2 solution for obtaining calcium alginate (CA) hydrogel beads filled with TS containing chlorogenic acid (HBCA/TS). The beads size, morphology, encapsulation efficiency, textural and viscoelastic properties, CGA release in simulated gastrointestinal conditions, and the molecular interactions between beads components using DSC and FTIR were evaluated. The sphericity of the HBCA/TS filled with TS was lower than that made with only calcium alginate, but the diameter was larger. CGA release from the beads was due to a complex interplay between matrix porosity and tortuosity. Highest release % of CGA occurred for HB0.75/0.25 which showed the lowest Tan delta-strain %, hardness and cohesiveness values. The diffusion-relaxation model involving two mechanisms described better the CGA release experimental data. (C) 2015 Elsevier Ltd. All rights reserved.