Flow properties of fruit fillings
2001
Wei, Y.P. | Wang, C.S. | Wu, J.S.B.
The flow properties of the fluid portion of fruit fillings were assessed to investigate the effects of gums. Results indicated that the shear rate-shear stress relations of the fluid portion of commercial fruit fillings and the model fillings made of waxy corn starch, fructose, citrate buffer, and a gum which could be guar gum, locust bean gum, CMC, xanthan gum or kappa-carrageenan, fit well into the Herschel-Bulkley equation for pseudoplastic fluids. The fluid portion of the commercial fruit fillings was characterized with a yield stress between 39-51 Pa, a consistency index between 52-104 Pa(.)s(n), and a flow index (n) around 0.4. In addition, the shear rate-shear stress relations could be fitted into a modified Herschel-Bulkley equation with a flow index fixed at 0.4. Addition of guar gum, locust bean gum and CMC increased while xanthan gum and kappa-carrageenan decreased the consistency and flow indices in the modified Herschel-Bulkley equation. The effect of gum addition on the apparent viscosity of model fillings varies with the type of gum, amount of addition, and shear rate.
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