2018年
Experimental comparison of static rheological properties of non-newtonian food fluids with dynamic viscoelasticity
Nihon Reoroji Gakkaishi
- ,
- 巻
- 46
- 号
- 1
- 開始ページ
- 1
- 終了ページ
- 12
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1678/rheology.46.1
- 出版者・発行元
- Society of Rheology
Correlations between static rheological properties (G: shear modulus, μ: viscosity, μapp: apparent viscosity) of four food fluids (thickening agent solution, yoghurt, tomato puree and mayonnaise) measured employing a newly developed non-rotational concentric cylinder (NRCC) method and dynamic viscoelastic properties (|G*|: complex shear modulus, G': storage shear modulus, G": loss shear modulus, |η*|: complex viscosity, tand: loss tangent, μapph: apparent viscosity) measured by a conventional apparatus (HAAKE MARS III) were studied. μapp and μapph for each sample fluid agreed well. μapp≒|η*| obeying the Cox-Merz rule was obtained for the thickening agent solution, μapp <
|η*| for mayonnaise and μapp ≪ |η*| for tomato puree and yoghurt. μ was lower than μapp or μapph for all samples, and reached μapp with an increasing shear rate. Plotting G and |G*| against the shear rate and angular velocity respectively in the same figure revealed G <
|G*| for tomato puree, G≒|G*| for yoghurt and G >
|G*| for mayonnaise and thickening agent solution. The applicability of two-element models in analyzing the viscoelastic behavior of sample fluids was investigated by comparing two characteristic times τM = 1/(ωtanδ) and τK = tanδ/ω, corresponding to Maxwell and Kelvin-Voigt models respectively and evaluated from measurements of tanδ, with τ = μ/G and τapp = μapp /Gapp calculated from rheological properties measured by the NRCC method. Here Gapp (= G(μ/μapp) is an apparent shear modulus newly defined to evaluate the shear-rate dependency of the elasticity of Non-Newtonian fluids. Results show τK agreed well with τapp, suggesting the possibility of applying the Kelvin-Voigt model to the viscoelastic behavior of sample fluids.
|η*| for mayonnaise and μapp ≪ |η*| for tomato puree and yoghurt. μ was lower than μapp or μapph for all samples, and reached μapp with an increasing shear rate. Plotting G and |G*| against the shear rate and angular velocity respectively in the same figure revealed G <
|G*| for tomato puree, G≒|G*| for yoghurt and G >
|G*| for mayonnaise and thickening agent solution. The applicability of two-element models in analyzing the viscoelastic behavior of sample fluids was investigated by comparing two characteristic times τM = 1/(ωtanδ) and τK = tanδ/ω, corresponding to Maxwell and Kelvin-Voigt models respectively and evaluated from measurements of tanδ, with τ = μ/G and τapp = μapp /Gapp calculated from rheological properties measured by the NRCC method. Here Gapp (= G(μ/μapp) is an apparent shear modulus newly defined to evaluate the shear-rate dependency of the elasticity of Non-Newtonian fluids. Results show τK agreed well with τapp, suggesting the possibility of applying the Kelvin-Voigt model to the viscoelastic behavior of sample fluids.
- ID情報
-
- DOI : 10.1678/rheology.46.1
- ISSN : 0387-1533
- SCOPUS ID : 85045831903