Optimization of the formulation for preparing Lactobacillus casei loaded whey protein-Ca-alginate microparticles using full-factorial design

Abstract

Context: This article presents specific approach for microencapsulation of Lactobacillus casei using emulsion method followed by additional coating with whey protein.

Methods: 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.

Results: 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.

Discussion: 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.

Conclusion: The advantageous properties of the L. casei-loaded microparticles make them suitable for incorporation in functional food and/or pharmaceutical products.

• Experimental design
• microencapsulation
• probiotic
• viability
• whey protein.

Acknowledgements

The authors would like to thank IMCD (UK) for the donation of sodium alginate (Protanal 10/60 LS, FMC Biopolymers, Philpadelphia, PA, USA). Gratitude is also expressed to the University Centre for Electron Microscopy at the Medical Faculty of the University of Niš, Serbia, for providing SEM images of the microparticles.