Functional properties of Lactobacillus casei C24 improved by microencapsulation using multilayer double emulsion.

Area of Science:

• Microbiology
• Biotechnology
• Food Science

Background:

• Probiotics require viability, adherence, and colonization to exert health effects.
• Maintaining probiotic properties during gastrointestinal transit is a significant challenge.
• Lactobacillus casei is a widely studied probiotic with potential health benefits.

Purpose of the Study:

• To encapsulate Lactobacillus casei using a layer-by-layer electrostatic deposition technique with alginate and chitosan.
• To evaluate the survival rate and functional properties of encapsulated L. casei after freeze-drying and simulated gastrointestinal digestion.
• To determine the protective effect of alginate-chitosan multilayer coatings on probiotic properties.

Main Methods:

• Double emulsion encapsulation of L. casei.
• Layer-by-layer electrostatic deposition of alginate and chitosan.
• Evaluation of cell count, cholesterol assimilation, surface hydrophobicity, auto-aggregation, and co-aggregation.
• Simulated in vitro gastrointestinal digestion (salivary, gastric, intestinal).

Main Results:

• Reservoir-type multilayer microcapsules with small particle size (6.2-12.2 μm) were successfully produced.
• Freeze-dried microcapsules retained the initial cell count (9.4 log UFC/g) and functional properties.
• Alginate-chitosan coating significantly improved L. casei resistance to simulated digestion.
• Encapsulation preserved cholesterol assimilation, hydrophobicity, and aggregation properties after in vitro digestion.

Conclusions:

• Alginate-chitosan multilayer encapsulation effectively protects Lactobacillus casei during freeze-drying and gastrointestinal transit.
• The enhanced microcapsules ensure probiotic viability and preserve essential functional properties.
• This encapsulation strategy guarantees probiotic presence and efficacy in the gastrointestinal tract.