Abstract:

The technological parameters of emulsification/internal gelation for calcium alginate microbeads were optimized
by single factor and orthogonal array experiments. The influence of sodium alginate (NaAlg) concentration, Span 80
concentration, volumetric ratio of water to oil (liquid paraffin) and mass ratio of CaCO3 to NaAlg on the morphology, particle
size distribution and yield of the microbeads was studied. The results showed that the average particle size of microbeads
was increased at higher NaAlg concentrations, but decreased at higher Span 80 concentrations and water to oil ratios, and not
significantly affected by the mass ratio of CaCO3 to NaAlg. The optimized conditions for preparing microbeads at 300–600 μm
with good morphology, uniform distribution, and high yield were as follows: 2 g/L Span 80, 12 g/L NaAlg, a mass ratio of
CaCO3 to NaAlg of 1:4, and a volumetric ratio of water to oil of 1:3. In addition, further experiments showed that after tenth
repeated use of liquid paraffin, microbeads prepared with it remained a good morphology and a higher yield.

Key words: emulsification/internal gelation, calcium alginate microbeads, process parameter optimization