| 1. |
- Corkery, Robert W., 1967-, et al.
(författare)
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A case for discotic liquid crystals in molten triglycerides
- 2007
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 23, s. 7241-7246
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Tidskriftsartikel (refereegranskat)abstract
- To date, essentially only two structural models have been proposed and debated in detail for explaining the liquid state order of triglycerides, and both invoke a form of thermotropic liquid crystalline order in triglyceride melts. These are the paralamellar model of Larsson et al. (J. Am. Oil Chem. Soc. 1992, 69, 835) and the nematic model of Cebula et al. (J. Am. Oil Chem Soc. 1992, 69, 130). An alternative discotic model is proposed here that adequately accounts for the broad small-angle X-ray diffraction peak often observed in the liquid state of fats and oils. In this alternative model, triglyceride molecules exist in the liquid state with fully splayed chains, approximating "Y"-shapes (Y-conformers). These are loosely bound within discs that stack into flexible, relatively short cylindrical rods of colloidal dimension, which in turn assemble into rod-packings with short-range order akin to disordered versions of thermotropic discotic liquid crystalline phases in other lipidic systems.
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| 2. |
- Rousseau, D, et al.
(författare)
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Microstructure of fat bloom development in plain and filled chocolate confections
- 2008
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Ingår i: Soft Matter. - 1744-683X .- 1744-6848. ; 4, s. 1706-1712
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Tidskriftsartikel (refereegranskat)abstract
- Temperature-controlled environmental scanning electron microscopy was used to examine the microstructural changes in plain solid chocolate and its counterpart stored against a tricaprylin-based filling cream. Sample storage at 26 C for 40 days led to significant changes in microstructure as a function of time. Surface imperfections (pores, pits, etc.) initially present on the filled confection disappeared within two days whereas those on the control did not throughout the storage period. Morphological changes on the surface of the control were dominated by the growth of needle-like crystals whereas spherulites appeared on the filled chocolate, with large crystals (upwards of 100 microns in length, in some cases) observed in both cases. From a microstructural perspective, both diffusion and capillarity appear to have a part in fat bloom initiation and propagation, though temperature and the presence of a filling fat strongly dictate which mechanism will dominate.
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