Evaluation of Alginate-Starch Polymers for Preparation of Enzyme Microcapsules

Flavourzyme (a protease-peptidase complex) was microencapsulated with sodium alginate and Hi-MaizeTM starch in varying concentrations and proportions for maximising encapsulation efficiency (EE). Seventy two percent EE was achieved for immobilising Flavourzyme using 1.8% (w/v) sodium alginate and 1% Hi-Maize[TM] starch with 30 min hardening of capsules in 0.1M calcium chloride solution. Hi-MaizeTM starch as a filler material improved EE and reduced the enzyme release during capsular hardening in calcium chloride solution. Increasing the concentration of sodium alginate solution (1.2 to 1.8 %, w/v) and calcium chloride concentration (0.05M to 1.0M) increased the EE. The optimum hardening time for the microcapsules in calcium chloride solution was 30 min. Shrinkage of microcapsules during hardening in calcium chloride was less with higher concentration of alginate. More spherical capsules were produced with up to 1.8% (w/v) sodium alginate and 1% Hi-MaizeTM starch solutions.