The mannoprotein of Saccharomyces cerevisiae, baker's yeast, is an emulsifying agent which could be used in foods and cosmetics. This glycoprotein emulsifier can be extracted simply with very good yield by autoclaving yeast cells in neutral buffer. The spent yeast from the beer and wine industries is a suitable raw material for its production. Protein detected by binding of Coomassie blue dye was essential for emulsifying activity. Components of the heat extracted material with greatest emulsifying activity included a high molecular weight fraction ($>$200 kDa) which provided viscous and durable emulsions, and a low molecular weight fraction ($<$14 kDA) which was very surface active and readily generated nonviscous emulsions. Mannoprotein and the small molecule surfactants lecithin and cetyltrimethylammonium bromide interacted synergistically to increase emulsifying activity at a weight ratio of 100:1 mannoprotein to surfactant. A correction was made to the formula for the Emulsifying Activity Index (Pearce, K. N. and J. E. Kinsella. 1978. J. Agric. Food Chem. 26:716-723), a measure commonly used for comparing protein emulsifiers.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.41154 |
| Date | January 1992 |
| Creators | Cameron, David R. (David Robert) |
| Contributors | Neufeld, R. J. (advisor), Idziak, E. S. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Microbiology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001324023, proquestno: NN87941, Theses scanned by UMI/ProQuest. |
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