Raman spectroscopy was used to study the protein structure in raw and
salted surimi from Pacific whiting, and in gels formed by setting (32°C),
cooking (86°C) or setting followed by cooking. The intensity of the peaks
assigned to disulfide bond stretching vibrations increased considerably in the
cooked and set-cooked gels. A smaller increase was found in the gels that
were subject to setting alone. Secondary structure estimation based on the
amide I band indicated a change from predominantly a-helical structure in raw
surimi to similar proportions of a-helical and anti-parallel p-sheet after setting.
A further increase in anti-parallel p-sheet and decrease in a-helix content
occurred during the kamaboko stage. The intensity of C-H stretching
vibrations of the aliphatic residues decreased after salting, setting and
cooking. The set and cooked gel had a better gel strength and fold score
than the cooked gel which, in turn, had better properties than the set gel.
Response surface methodology was used to determine the optimal setting
and cooking time and temperature conditions resulting in a maximized gel
strength, fold score and color, (whiteness index), and a minimized gel
expressible liquid. Cooking temperature was the variable that had the
strongest influence on the gel quality characteristics. Level set programming, a global optimization method, gave essentially the same results as a gradient
based optimization method. The results obtained by these two methods were
better than those generated by the Simplex technique.
Using a formulation composed of pink salmon surimi, salt, whey protein
concentrate and wheat starch, an optimal final product, kamaboko sausage,
was developed. In addition, when this formulation was applied to herring
surimi, the kamaboko obtained had similar gel strength and elasticity as a
commercial surimi-based product. The effects of frozen storage conditions of
roe herring on its gel making ability (GMA) were investigated. Frozen storage
at around -45°C maintained the GMA for seventy days while storage at -83°C
further increased the GMA period.
The viscous properties of a salmon surimi paste were studied using a
rotational viscometer. The paste behaved as a shear thinning fluid with a
yield stress that increased with temperature up to 21 °C. Viscosity also
increased with temperature up to 21 °C, possibly because of protein-protein
interactions. The Theological data were reasonably well represented by a
simple model which takes into consideration the effects of both shear rate and
temperature. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/6246 |
| Date | 05 1900 |
| Creators | Bouraoui, Moez Mohamed |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Format | 4492263 bytes, application/pdf |
| Rights | For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. |
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