The properties of genetic variants of $ alpha sb{ rm s1}$-casein (BB, AB), $ beta$-casein (A$ sp1$A$ sp1$, A$ sp2$A$ sp2$, A$ sp1$A$ sp2$, A$ sp1$A$ sp3$, A$ sp2$A$ sp3$, A$ sp1$B, A$ sp2$B, BB), $ kappa$-cn (AA, AB, BB) and $ beta$-lactoglobulin (AA, AB, BB) were compared. The caseins and $ beta$-lactoglobulin were purified by mass ion exchange chomatography. Model systems of $ alpha sb{ rm s1}$- and $ kappa$-caseins were compared with respect to their stability towards calcium ions and other major milk salts precipitation. $ beta$-Casein, $ alpha sb{ rm s1}$-casein BB + $ beta$-caseins and $ kappa$-casein were also compared in their ability to resist calcium ion precipitation. $ kappa$-casein AB was a better stabilizer of $ alpha sb{ rm s1}$-casein than the BB and AA variants. $ alpha sb{ rm s1}$-Casein BB resisted calcium ion precipitation more than the AB variant in presence of $ alpha$-lactose, citrate, chloride and magnesium ions. $ kappa$-Casein BB stabilized $ alpha sb{ rm s1}$-casein AB more than the BB variant in presence of calcium and phosphate ions. Solubility of $ kappa$-casein AA, however, was greater than that of $ kappa$-cn BB and $ kappa$-cn AB variants in calcium and phosphate solutions. As in $ alpha sb{ rm s1}$-casein, significant differences were also found among $ kappa$-casein variants in stabilizing $ beta$-casein against calcium ion precipitation. $ beta$-Caseins A$ sp1$A$ sp1$, A$ sp2$A$ sp2$ and A$ sp1$B produced the most stable micelles while those of A$ sp2$B and B variants the least at 0.03-0.25 $ kappa$-cn/$ beta$-casein ratios and 20 mM Ca$ sp{2+}$. However, stability of micelles formed from $ alpha sb{ rm s1}$-cn + $ beta$-cn A$ sp2$A$ sp3$, $ alpha sb{ rm s1}$-cn + $ beta$-cn A$ sp1$A$ sp3$, and $ alpha sb{ rm s1}$-cn + $ beta$-cn A$ sp2$A$ sp2$ caseins were higher than those of $ alpha sb{ rm s1}$-cn + $ beta$-cn A$ sp1$A$ sp2$, $ alpha sb{ rm s1}$-cn + $ beta$-cn A$ sp1$B and $ alpha sb{ rm s1}$-cn + $ beta$-cn A$ sp1$A$ sp1$.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.74578 |
| Date | January 1990 |
| Creators | Imafidon, Gilbert Idolo |
| 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: 001116706, proquestno: AAINN66520, Theses scanned by UMI/ProQuest. |
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