The rheological, color, micro-structural, and electrical properties of surimi
seafood gels were investigated. Various starches and protein additives at different
ratios were evaluated with Alaska pollock surimi under ohmic heating at different
heating rates to determine their functional properties and further to compare these
properties with those of conventionally cooked gels.
Native starches at low concentration were able to enhance rheological
properties due to their gelatinization during heating. Pregelatinized starch
decreased texture properties; however, it could suppress the undesirable appearance
of the final product because its granules could absorb the surrounding water during
chopping and perform a higher degree of retrogradation when cooling. A mixture
of native and pregelatinized starches showed a positive trend at high concentration.
The more starch added, the lower the L* and b* values of the gels. Protein additives improved textural properties, but negatively affected gel colors. Lower
moisture content of the final products showed higher strength in texture, but lower
lightness values.
Gels cooked under ohmic heating with a slow heating rate mostly exhibited
better texture properties than conventionally cooked gels. Electrical conductivities
increased when temperature increased, resulting in a linear relationship. Electrical
conductivity also significantly increased with moisture content, and slightly
increased with applied frequency and voltage. There were some changes in the
magnitude of electrical conductivity of surimi-starch paste when temperature
increased, most obviously seen at a high concentration of native starch with slow
ohmic heating. This indicated that starch gelatinization affected the electrical
conductivity of surimi-starch paste while heating. / Graduation date: 2003
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/27080 |
| Date | 04 September 2002 |
| Creators | Pongviratchai, Panida |
| Contributors | Park, Jae W. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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