Microbiological study of lyophilized dairy kefir

Area of Science:

• Microbiology
• Food Science
• Biotechnology

Background:

• Dairy kefir is a fermented milk product with significant probiotic properties.
• Lyophilization (freeze-drying) is a common method for preserving microorganisms but can impact their viability and functionality.
• Maintaining the intrinsic inhibitory power of kefir post-lyophilization is crucial for its therapeutic and commercial applications.

Purpose of the Study:

• To evaluate the effectiveness of different cryoprotective agents and regeneration media for preserving the inhibitory power of dairy kefir after lyophilization.
• To identify optimal conditions for post-lyophilization kefir regeneration to ensure microbial viability and functional activity.

Main Methods:

• Lyophilization of dairy kefir using various cryoprotectors: ribitol, sodium glutamate, and glycerol.
• Regeneration of lyophilized kefir pellets in different media: water and milk.
• Assessment of the intrinsic inhibitory power of the regenerated kefir.

Main Results:

• Glycerol demonstrated superior cryoprotective efficacy compared to ribitol and sodium glutamate.
• Sodium glutamate was found to be an unsatisfactory cryoprotector for kefir lyophilization.
• Regeneration in milk or water showed varying effects, with glycerol-yielding best results.

Conclusions:

• Glycerol is a highly efficient and cost-effective cryoprotector for preserving the inhibitory power of dairy kefir post-lyophilization.
• The choice of cryoprotector significantly impacts the survival and functional capacity of kefir microorganisms after freeze-drying.
• Optimized lyophilization and regeneration protocols are essential for maintaining the probiotic potential of dairy kefir.