Preparation of hyaluronic acid‐loaded liquid‐core hydrogel beads with acceptable mechanical properties and thermal stability

ABSTRACT Background Hyaluronic acid liquid‐core hydrogel beads (HA‐LHB) is a good way for oral intake of HA. However, HA may affect the reaction–diffusion of SA and Ca 2+ leading to poor mechanical properties, since HA is a polyanionic electrolyte having electrostatic effect and a certain spatial site‐blocking effect. Results In the present study, the mechanical properties of HA‐LHB were modified from bathing solution, core solution, secondary calcium bath time. The mechanical properties varied with the SA structure and concentration in bathing solution, where SA with high G (Guluronic acid) segment compounded with SA with high M segment (Mannuronic acid) at a mass ratio of 7:3 with a 11 g/kg concentration showed the best mechanical properties. The secondary calcium bath can highly improve the mechanical properties due to the tight network by bidirectional cross‐linking, and 15 min reaction reached the plateau if Ca 2+ is sufficient. And the mechanical properties were positively correlated with calcium lactate concentration only at <70 g/kg in core solution, but the diffusion of Ca 2+ was hindered by tight gel network at higher concentrations. Moreover, the mechanical properties can be maintained during heat treatment, due to the rearrangement of alginate network structure. Conclusion Our results suggested that the problem of poor mechanical properties of LHB in the presence of high HA concentration can be avoided by process control, which may broaden the development of HA and popping boba markets. This article is protected by copyright. All rights reserved.