| Project/Area Number |
07660164
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
食品科学・栄養科学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
MATSUMURA Yasuki Kyoto University, Research Institute for Food Science, Associate Professor, 食料科学研究所, 助教授 (50181756)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1996: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1995: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | emulsion / micelle / lipid oxidation / unsaturated fatty acids / lipoxygenase / protein / surfactant / リポソーム |
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| Research Abstract |
Relation between conformation and oxidation of lipids at the oil-water interface in dispersed systems has been investigated. Analyzes of molecular orientation of triglycerides at the oil-water interface by DSC,FT-IR and surface pressure measurements revealed that unsaturated fatty acids were loosely packed at the interface. However, the addition of surface active crystals increased the molecular orientation of triglyceride molecules at the interfaces. The oxidation of various kinds of fatty acid esters induced by hydroxyl radical in emulsion systems was studied. The obtained results have shown that the degree of oxidation does not directly relate to the structure of fatty acid, but to the emulsifiers used for emulsification. The use of ionic surfactants increased the degree of oxidation of fatty acid esters as compared to the use of non ionic surfactants. The oxidation mechanism in emulsions stabilized by proteins were different from that in emulsions stabilized by surfactants. These r
… More
esults indicate that the important factor is not the conformation of lipids itself, but the interaction of lipid and emulsifiers at the interfaces in relation to the oxidation of lipids. In order to obtain the information on the physical states and interaction of emulsifiers at the interface, Iipoxygenase reaction in emulsions stabilized by various emulsifiers was investigated. The high oxygenation rates were observed in the emulsions stabilized by proteins, whereas the oxygenation rate was very low in the emulsion stabilized by surfactants. It is thought that adsorbed proteins form the two-dimensional network structure at the interfaces in which the lateral diffusion of protein molecule is highly restricted. Lipoxygenase may be able to draw the substrate lipid from the crevice in the two dimensional network at the interface. However, surfactants are easy to diffuse at the interface to move rapidly the place with high interfacial energy level and can fill the interface. It may be difficult for lipoxygenase to draw the substrate lipid from such an interface densely filled by surfactants. The results obtained through this research project may become fundamental findings for the construction of the safe and efficient antioxidant systems in real foods. Less
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