PRODUCTION OF ALGINATE BEADS BY EMULSIFICATION INTERNAL GELATION .2. PHYSICOCHEMISTRY

Alginate microspheres were produced by emulsification/internal gelatio n of alginate sol dispersed within vegetable oil, Gelification was ini tiated within the alginate sol by a reduction in pH (7.5 to 6.5), rele asing calcium from an insoluble complex. Smooth, spherical beads with the narrowest size dispersion were obtained when using low-guluronic-a cid and low-viscosity alginate and a carbonate complex as the calcium vector. A more finely dispersed form of the complexed calcium within t he alginate sol promotes a more homogeneous gelification. Microsphere mean diameters ranging from 50 mu m to 1000 mu m were obtained with st andard deviations ranging from 35% to 45% of the mean.