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چکیده
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This work aimed to examine the impacts of ultrasonic treatments (40 kHz) at different intensities (0, 75, and 150 W) and time (0, 5, 10, 15, and 20 min) on the rheological properties of different concentrations (at 3 levels of 0.10, 0.15, and 0.20 %, w/v) of xanthan gum solution (XGS). The results confirmed that the apparent viscosity of XGS decreased from 68.75 to 30.38 mPa.s with increasing ultrasonic power from 0 to 150 W (shear rate = 61 s−1, 0.2 %, 20 min). In addition, the apparent viscosity of XGS decreased by enhancing the sonication time. Various rheological equations (power-law, Bingham, Herschel-Bulkley, Casson, and Vocadlo) were employed to fit the empirical values, and the results confirmed that the power-law equation was the best fit to describe the flow behaviour of XGSs. The consistency coefficient (CC) of XGS significantly decreased from 1222.7 to 635.1 mPa.sn (p < 0.05) while ultrasonic power enhanced from 0 to 150 W (0.2 %, 10 min). Furthermore, the CC of XGS decreased significantly (p < 0.05) while the duration of ultrasound treatment enhanced. The flow behaviour index (FBI) of various concentrations of XGS enhanced while the intensity and duration of ultrasound treatment enhanced.
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