Steady, Dynamic, Creep, and Recovery Analysis of Ice Cream Mixes Added with Different Concentrations of Xanthan Gum
文摘
Different xanthan gum concentrations (0鈥?.8聽%) were tested, and the rheological properties of ice cream mixes were characterized as linear viscoelastic solids. Ostwald de Waele was successfully used to fit the steady shear data of ice cream mixes exhibiting a pseudoplastic flow (R 2鈥?gt;鈥?.982). The samples with xanthan gum were characterized as strong gel-like macromolecular dispersions with G鈥?much greater than G鈥?but without a cross-point in the whole range of frequency applied. Cox鈥揗erz rule was not applicable to the ice cream mixes. Steady and dynamic rheology of the ice cream mixes changed with increasing xanthan gum concentration. Besides, the four-component Burger model consisted of the association in series of the Maxwell model and the Kelvin鈥揤oigt model was used to characterize the viscoelasticity. It was also found that the final percentage recovery parameters; J SM, J 鈭?/sub>, J KV, and %R (compliance of Maxwell spring and dashpot, Kelvin鈥揤oigt element and R, respectively) of the ice cream mixes were dramatically changed by the xanthan gum concentration, increasing the internal structure parameters G 0, G 1, 畏 0, and 畏 1 (elastic moduli of Maxwell and Kelvin鈥揤oigt springs and corresponding dashpot viscosities, respectively).