Estimating flow behavior of microwave-treated Wild sage seed gum dispersions using various flow behavior models

This study aimed to analyze the influence of microwave treatment (MT) at various time intervals on the viscosity and flow behavior of Wild sage seed gum (WSSG) dispersion (0.2%, w/v). The flow behavior of WSSG dispersions were calculated from the resulting flow curves using four flow behavior models (Power law (PL), Bingham, Herschel-Bulkley (HB), and Casson). The fit quality of the selected models was evaluated using correlation coefficient (r), sum of squared error (SSE), and root mean square error (RMSE). It was observed that the apparent viscosity of WSSG dispersion reduced from 68 mPa.s to 19 mPa.s as the shear rate (SR) increased from 12.2 s-1 to 171.2 s-1. Additionally, the apparent viscosity of the samples reduced from 34 mPa.s to 28 mPa.s as the MT time increased from 0 to 3 min (SR=49 s-1). The HB model, which is a combination of Bingham and PL models, fitted the data very well with an overall r of more than 0.9990 and, SSE and RMSE values of lower than 0.0123, and, 0.0310, respectively, therefore, used to describe the shear stress (SS) and apparent viscosity of WSSG dispersions. The consistency coefficient of WSSG dispersion decreased significantly from 0.185 Pa.sn to 0.155 Pa.sn (p<0.05) with increasing MT time from 0 to 3 min. Also, the flow behavior index (PL and HB models) of dispersions increased as the MT time increased.