Liquid-core hydrocolloid capsules

Production and modification of the mechanical and slow-release properties of liquid-core hydrocolloid capsules are described. Proteins with molecular weights of 2500-205 000 Da were entrapped within liquid-core alginate, alginate-chitosan or alginate-polylysine capsules. The ratio R(t) between protein concentration of a certain protein in the external fluid into which capsules were immersed, at a given time, and the equilibrium evaluated concentration of that same protein in the external fluid was calculated and plotted against time. These diffusion results were compared to diffusion from 'whole' alginate bends. Better slow-release properties were achieved when polylysine or chitosan were used to change the permeability of the alginate membrane. These chemical treatments also strengthened the membrane and affected its brittleness.