Investigation of rheological behavior of Kyrgyz traditional food Sary mai

Abstract

In this study, the rheological properties of shelf-stable and calorie-rich traditional product Sary mai, known as ghee were investigated at various temperatures for the first time. It was found that ghee at 20-30°C reacted as a non-Newtonian pseudoplastic fluid with yield stress value and flow curves fitted to the Herschel-Bulkley model. With increasing the temperature (40-50°C), ghee become more fluidly and Ostwald-De-Waele model was found as the most appropriate to fit the flow curves with correlation coefficient R2 = 0.9985‒0.9999. The effective viscosity of ghee decreased from 2.613 to 0.023 Pa·s with increasing temperature from 20 to 50°C. The Arrhenius relationship was employed to estimate the flow activation energy for the ghee samples and was found as Ea = 134.3 ± 0.5 kJ/mol with R2 = 0.9385. The amplitude-sweep was performed at 20°C for determining the yield point and the flow point. Obtained parameters provide useful information for the optimization of industrial processes and control of quality and authenticity of ghee.