Optimization of the formulation for preparingLactobacillus caseiloaded whey protein-Ca-alginate microparticles using full-factorial design

This article presents specific approach for microencapsulation of Lactobacillus casei using emulsion method followed by additional coating with whey protein.Experimental design was employed using polynomial regression model at 2nd level with three independent variables, concentrations of alginate, whey protein and CaCl2. Physicochemical, biopharmaceutical and biological properties were investigated.In 11 series generated, negatively charged microparticles were obtained, with size 6.99-9.88 µm, Ca-content 0.29-0.47 mg per 10 mg microparticles, and viability of the probiotic 9.30-10.87 log10CFU/g. The viability after 24 hours in simulated gastrointestinal conditions was between 3.60 and 8.32 log10CFU/g.Optimal formulation of the microparticles that ensures survival of the probiotic and achieves controlled delivery was determined: 2.5% (w/w) alginate, 3% (w/w) CaCl2 and 3% (w/w) whey protein.The advantageous properties of the L. casei-loaded microparticles make them suitable for incorporation in functional food and/or pharmaceutical products.