Food Structure
Changes in the Ultrastructure of Emulsions as a Result of Electron Microscopy Preparation Procedures
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Abstract
Various methods of preparing emulsions for electron microscopy were examined with peanut oil/protein and ice cream mix emulsions. For transmission electron microscopy {TEM) , fresh peanut oil/bovine serum albumin emulsions were mixed with 2% agar , fixed in phosphate-buffered (pH 7 . 0) 4% glutaraldehyde solution and postfixed in phosphate-buffered (pH ? . 0) 1% osmium tetroxide alternatively , the glutaraldehyde- fixed samples were briefly rinsed in acetone prior to postfixation . Both preparations yielded satisfactory fat globule preservation. Similar emulsions were prepared on loops and suspended over vapors of 25% gJ nt.RrBl r'lehyr'le Rnc'l 1% oRmi urn tetroxide . This preparation resulted in angular fat globules surrounded by a heavy protein precipitate.
Ice cream mix emulsions were prepared for TEM study by mixing with 4% agar , mixing with 2% agarose or using agar tubes. After fixation in phosphate- buffered 4% glutaraldehyde (pH 7 .0) solution , the samples were postfixed in either phosphate/imidazole buffe red (pH 7 . 0) or phosphate- buffered (pH 7 .0) 1% osmium tetroxide . ~lixing with 2% agarose and postfixing in imidazole/phosphate buffered osmium tetroxide yielded the best results . A clearly visible fat membrane and well-delineated fat crystals were observed.
Scanning electron microscope (SEM) studies o!' peanut oil/casein emulsions mixed with 4% agar yielded good results whereas in ice cream mix emul s i ons , the results were inconclusive.
Recommended Citation
Liboff, M.; Goff, H. D.; Haque, Z.; Jordan, W. K.; and Kinsella, J. E.
(1988)
"Changes in the Ultrastructure of Emulsions as a Result of Electron Microscopy Preparation Procedures,"
Food Structure: Vol. 7:
No.
1, Article 8.
Available at:
https://digitalcommons.usu.edu/foodmicrostructure/vol7/iss1/8