1996 Fiscal Year Final Research Report Summary
Relationship between the physico-chemical Property of Xanthan and its Antioxidative Activity in Emulsion.
| Project/Area Number |
07680038
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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 |
家政学
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| Research Institution | Yamaguchi Prefectural University |
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Principal Investigator |
SHIMADA Kazuko Yamaguchi Prefectural University, Department of Food and Life Science, Professor, 家政学部, 教授 (70145936)
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| Project Period (FY) |
1995 – 1996
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| Keywords | Xanthan / Antioxidant / Chelation / Iron-binding property / Dissolved oxygen / Emulsion / Viscosity / Cellulase |
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| Research Abstract |
Xanthan have been considered as stabilizing an oil/water (O/W) emulsion by increasing the viscosity of the aqueous phase and inhibiting its coalescence. Xanthan chelated such as a metal ion as Fe^<2+> between two side chains with a pyruvate residue and thereby inhibited the oxidation of soybean oil in the emulsion. The effects of emulsion viscosity and oil-droplet size on the oxidation of soybean oil in O/W emulsions containing xanthan or other polysaccharides were investigated. The antioxidative effects were evaluated by measuring the Fe^<2+>-induced consumption of oxygen dissolved in the O/W emulsion. The degree of oxygen consumption was, from the lowest, in the order of xanthan<pectin<guar gum<Tragacanth gum, and was closely related to the Fe^<2+>-binding ability of the polysaccharides. The oxygen consumption was also affected by the viscosity of the aqueous solution in the emulsion, but not by the oil-droplet size.
The viscosities of xanthan and deacetylated xanthan solutions were decreased by the treatment of cellulase (Trichoderma viride). The deacetylated and cellulase-treated xanthan was smaller in molecular size. Both low-molecular-weight xanthans retained the pyruvate residue, Fe^<2+>-binding and chelating abilities (dissociation constant and number of binding sites), and showed strong antioxidative activity.
The antioxidative mechanism for xanthan can be accounted for primarily by its high metal-binding ability, and additionally by its viscous behavior.
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