2001 Fiscal Year Final Research Report Summary
Mechanism of damages of polysaccharide gels and related foods caused by freezing-thawing cycle
| Project/Area Number |
12680136
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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 |
食生活
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| Research Institution | Osaka Prefecture University (2001)
Kyoto Prefectural University (2000) |
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Principal Investigator |
KITAMURA Shinichi Osaka Prefecture University, Graduate Schools of Agriculture and Biological Sciences, Professor, 大学院・農学生命科学研究科, 教授 (60117869)
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| Project Period (FY) |
2000 – 2001
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| Keywords | gel / freezing-thawing cycle / differential scanning calorimetry / small angle X-ray scattering / cooked rice rice / immunohistochemistry / antibody |
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| Research Abstract |
Structural changes in curdlan gel caused by a freezing-thawing cycle have been studied by differential scanning calorimetry (DSC) and small angle X-ray scattering (SAXS). The amount of eroded water from curdlan gel was estimated to be 32 and 40 %, depending on the freezing rate,for 0.5 K/min and 0.05 K/min, respectively. A network structure constructed by triple helical and random coil structures was not changed in a molecular level drastically, but a change in sub micrometer-order was suggested from SAXS profiles. Damages in cooked rice by a freezing- thawing cycle and keeping at 5 ℃ was comparatively studied using DSC. The keeping at 5 ℃ caused worse change in texture compared with the freezing-thawing treatment. The change is ascribed to the retrogradation of starch in cooked rice at 5 ℃. Immunohistochemical staining using an anti-curdlan rabbit antibody for starch-curdlan mixture gels discriminated the curdlan domains from the starch domains, and thus the local changes in curdlan domains by a freezing-thawing cycle could be clarified. Anti-arabinoxylan rabbit antibody was useful for staining arabinoxylan gel in cell wall of bamboo shoot. This will enable to identify the change the arabinoxylan gel in the cell wall by a freezing-thawing cycle.
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