Understanding the physiology of probiotic yeast cells under different formulation, processing and environmental conditions

Tanangteerapong, Duangkanok (2015). Understanding the physiology of probiotic yeast cells under different formulation, processing and environmental conditions. University of Birmingham. Ph.D.


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Probiotics are live microorganisms including yeast and bacteria used as food supplements to offer health benefits. Currently available forms of yeast probiotic products include powder and gelatine capsules. A new yeast probiotic product in tablet dosage form has been developed in order to prolong product shelf life and improve product stability. The aim of the present work was to study the physiological states of yeast cells in various formulation and conditions, and to develop a rigid tablet which contains the adequate number of active yeast cells. Yeast cells became injured and had lower culturability when they were exposed to a high shear force of homogenization and compaction pressure. Tablets containing freeze dried yeast resulted in low tensile strength and could not withstand handling. Encapsulation of yeast cells with pectin demonstrated better survival and showed desirable water activity. Furthermore, the material properties of calcium pectinate beads have been investigated. A compaction of CaP beads into tablets at 90 MPa created rigid tablets with the adequate number of viable cells. Overall, encapsulated cells in CaP beads were protected more from damage during compaction and show more resistance to stress during storage. The use of flow cytometry together with fluorescent dyes for the monitoring of cell physiological states has also been demonstrated.

Type of Work: Thesis (Doctorates > Ph.D.)
Award Type: Doctorates > Ph.D.
College/Faculty: Colleges (2008 onwards) > College of Engineering & Physical Sciences
School or Department: School of Chemical Engineering
Funders: Other
Other Funders: Government of Thailand
Subjects: T Technology > TP Chemical technology
URI: http://etheses.bham.ac.uk/id/eprint/5742


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