Microencapsulation of probiotic bacteria using thermo-sensitive sol-gel polymers for powdered infant formula

Abstract

In this study the application of thermo-sensitive sol-gel polymers in microencapsulation formulation of probiotic bacteria, Bifidobacterium animalis spp lactis, for powdered infant formula (PIF), which is reconstituted at 70 °C, has been assessed. A double-layered microcapsule containing hydroxypropyl methyl cellulose (HPMC) as an inner layer and an outer layer, as the smart coating layer, based on a combination of hydroxypropyl cellulose (HPC) and poloxamer was designed. Generally, this specific microencapsulation provided superior protection against the reconstitution temperature. A high molecular weight of HPC and a greater thickness of the smart coating layer resulted in a delayed release of the bacteria from the microcapsules especially in the PIF composition. However, this was compensated by a high stability of the bacteria at 70 °C. Both the surface texture and particle size distribution of microcapsules have been respectively characterised by scanning electron microscopy and particle size analysis.

• Bifidobacterium animalis spp lactis
• hydroxypropylmethyl cellulose
• hydroxypropyl cellulose
• lower critical solution temperature
• poloxamer
• smart polymer

Acknowledgements

The author wishes to acknowledge Dr. Herbert Huttlin, Mr. Thomas Kordic, Mr. Michele Pietrantuono, Mrs. Anita Ruetzler and Mr. Diter May, all from Innojet Company (Esteinen Germany), for providing the Innojet Ventilus machine and other facilities and for performing the micro-encapsulation process. Likewise, the author acknowledges Dr. Alex Schneider from iDrug (Berlin Germany) for the performance of the microbiological tests.

Declaration of interest

This study was carried out in the framework of the research and development department's activities of Degama Smart Ltd. The author is the Chief Science and Technology Officer of the company.