Polymorphic crystal forms in food fats contribute to physical characteristics of the fats and consequently to their performance in fat based foods. In the present study the phase transitions associated with polymorphism behavior of common food fats were investigated. The polymorphism of butters, margarines, cocoa butter and cocoa butter products were determined and the effects of certain ingredients and conditions of temperature were studied. The following polymorphic forms were detected: sub-alpha, alpha, beta' , beta'3, beta' 2, beta, beta2, and beta1; however, not all forms were observed in all fats. Margarines contained beta' and beta forms depending on their fat constituents, while butter, cocoa butter, and fat blends consisted of alpha, beta' and beta; only the beta' form of butter showed a sharp melting point. Rapeseed oil exhibited alpha, beta1 and beta 2 forms, depending on the degree of hydrogenation. / DSC measurements of fat blends were correlated with viscosity index measurements from Universal Material Testing Machine (UMTM) using a single cycle, back extrusion technique. A correlation of R2 = 0.70 (p = 0.95) was obtained. Viscosity index decreased as temperature increased, suggesting a possible relationship between viscosity index and solid fat fraction. This suggests that viscosity index could be a potential indicator of food fat textural properties which are evaluated by DSC. (Abstract shortened by UMI.)
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.20613 |
| Date | January 1998 |
| Creators | Zamani, Younes. |
| Contributors | Alli, I. (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 | Master of Science (Department of Food Science and Agricultural Chemistry.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001610037, proquestno: MQ44324, Theses scanned by UMI/ProQuest. |
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