• Korean Journal of Food Science and Technology
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• v.35 no.1
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• pp.155-158
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• 2003

Time-dependent flow properties of mustard pastes were measured at various total solid contents $(TS,\;18{\sim}30%)$ and shear rates $(15{\sim}25\;s^{-1})$ using a Haake concentric cylinderical viscometer. Experimental data of the stress decay with time of shearing were fitted to three mathematical models proposed by Weltman, Figoni and Shoemaker, and Hahn. Time-dependent flow behaviour of mustard paste increased with increase in TS, but was found to vary in the range of shear rate investigated. Time-dependent model of Weltman was found to be most applicable $(average\;R^2=0.96)$ for mustard paste. Shear stresses for structure breakdown increased with increase in TS, while the structure breakdown rate decreased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.5
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• pp.860-864
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• 2000

The steady and dynamic shear rheological properties of traditional kochujang fermented at three different temperatures (20${^circ}C$, 25${^circ}C$ and 30${^circ}C$) were studied. Flow of kochujang samples showed time dependence, which was quantitatively described by the Weltman model, Kochujang samples were highly shear thinning fluids (n=0.25~0.27) with large magnitudes of Casson yield stresses (1.09~1.21 kPa). Consistency index (K) and apparent viscosity (${\eta}_{a,20}$) increased with increase in fermentation temperature of kochujang. Storage (G') and loss (G") moduli increased with increase in frequency (ω), while complex viscosity (${\eta}^{\ast}$) decreased. Based on dynamic shear data, kochujang samples exhibit structural properties similar to weak gels. The complex and steady shear viscosities at different fermentation temperatures followed the Cox-Merz superposition rule with the application of the shift factor (a=0.011~0.016).

• Food Science and Biotechnology
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• v.14 no.3
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• pp.413-415
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• 2005

Time-dependent flow properties of commercial kochujang (hot pepper-soybean paste) were evaluated at various shear rates (5, 15, 25, and $35\;sec^{-1}$) and temperatures (5, 15, and $25^{\circ}C$). Flow properties of all samples showed thixotropic behaviors, which were qualitatively evaluated and quantitatively described by the Weltman, Hahn, and Figoni and Shoemaker models. Time-dependent flow properties of kochujang were found to vary over the range of the shear rate and temperature investigated. Time-dependent models of Weltman and Hahn were suitable ($R^2=0.923-0.987$) for commercial kochujang.

• Culinary science and hospitality research
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• v.8 no.3
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• pp.295-308
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• 2002

The effect of vinegar concentration (＋30%, 0% and -30%) on the emulsion stability of mayonnaise dressing was studied by the measurement of theological test and sensory evaluation. The emulsion stability of mayonnaise dressing increased with increase in vinegar concentration. The results of steady shear theological test indicated that C sample of the highest vinegar concentration (＋30%) exhibited higher emulsion stability than other samples. The dynamic shear datas were similar to steady shear theological data. The mayonnaise dressing samples showed time dependence, which was quantitatively described by the Weltman model. Parameters A and B indicated that the structure of C sample exhibited more stable than that of A (-30%) and B (0%) samples. The amount of oil separation was less than that of A and B samples. The results of sensory evaluation were similar to those of theological and emulsion tests.