Isolated $ alpha sb{ rm s1}$-casein, $ alpha sb{ rm s2}$-casein, $ beta$-casein, $ kappa$-casein of different phenotypes, whole casein of different phenotype combinations of $ alpha sb{ rm s1}$-/$ beta$-/$ kappa$-casein, and $ beta$-lactoglobulin of different phenotypes were prepared and used in the study. Surface properties at the air-water interface, voluminosity and hydration, emulsifying capacity and emulsion stability, foaming and gelling properties were investigated to understand the relationship between the structure and functionalities of milk proteins. Phenotype CC of $ alpha sb{ rm s1}$-casein, A$ sp1$A$ sp1$ and A$ sp1$A$ sp2$ of $ beta$-casein, AB of $ kappa$-casein decreased surface tension at a faster rate than the other, phenotypes within the casein system under consideration. $ beta$-Casein, when compared to $ alpha sb{ rm s1}$-casein, $ alpha sb{ rm s2}$-casein and $ kappa$-casein, was the most surface active protein. The $ alpha sb{ rm s1}$-/$ beta$-/$ kappa$-casein haplotypes of BB/A$ sp2$A$ sp2$/AA and BB/A$ sp1$A$ sp1$/BB were found to be associated with higher surface activity than the other ten combinations of whole casein. $ alpha sb{ rm s-1}$-Casein BB, $ beta$-casein A$ sp2$A$ sp2$ and $ kappa$-casein AB had higher values for voluminosity and hydration than the other phenotypes of the corresponding individual casein. Within the four caseins, $ beta$-casein had the strongest ability to entrap water and the highest value for voluminosity, followed by $ alpha sb{ rm s1}$-casein, $ alpha sb{ rm s2}$-casein and $ kappa$-casein. Whole casein with the combination of BB/A$ sp2$B/BB had the highest value for voluminosity and hydration. Analysis of model emulsions suggested that the emulsifying properties of different sources of protein were dependent on the oil content. $alpha sb{ rm s1}$-Casein BB in 10% oil emulsion, $ beta$-casein A$ sp2$A$ sp2$ in 10% and $ beta$-casein A$ sp2$B in 40% oil emulsions were the best stabilizers. $ kappa$-Casein
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.42037 |
| Date | January 1997 |
| Creators | Gao, Hong, 1957- |
| Contributors | Ng-Kwai-Hang, K. F. (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 Animal Science.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001565585, proquestno: NQ29940, Theses scanned by UMI/ProQuest. |
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