Iranian Research Organization for Science and Technology (IROST) Innovative Food Technologies 2783-350X 3 2 2016 02 20 Investigation of the steady shear flow behavior of Iranian peach concentrate: influence of concentration and temperature Investigation of the steady shear flow behavior of Iranian peach concentrate: influence of concentration and temperature 11 22 282 10.22104/jift.2016.282 FA Ali Reza Yousefi 1Assistant Proffesor, Department of Chemical Engineering, University of Bonab, Bonab, Iran Fatemeh Shahi Former M.Sc. Student, Department of Food Science and Technology, Maragheh Branch, Islamic Azad University, Maragheh, Iran Hossein Sheikhloie Assistant Proffesor, Department of Chemistry and Food Science and Technology, Maragheh Branch, Islamic Azad University, Maragheh, Iran Journal Article 2015 11 03 Among the juice, peach juice has high popularity and in terms of nutrition also has been highly regarded. Iranian peach puree is one of the main sources of peach juice production in Iran. In this research, steady shear flow behavior of peach concentrate produced from this puree were investigated at the concentration of 5, 10, 15, 20 and 25 °Bx. and temperature of 5, 25, 45 and 65 °C. The shear stress-shear rate data obtained for the concentrates were fitted by different rheological models including Newtonian, Power law, Bingham and Herschel-Bulkley. In addition, the concentration dependency was investigated by power law and exponential models and the temperature dependency was evaluated by the Arrhenius-Eyring model. All the samples showed pseudoplastic behavior. Power law model (Ostwald-de Waele’s model) with high determination coefficient (R² = 0.934-0.999) and low root mean square errors (RMSE = 0.027-0.327) had the best fit to the experimental data. It was observed that increase in the temperature leads to an increase in the flow behavior index (<em>n</em>) and a decrease in the consistency coefficient (<em>k</em>). On the other hands, increasing the concentration decreased <em>n</em> and increased <em>k</em> values. Power-law model also predicted the concentration dependency of apparent viscosity (η₅₀) with a high precision. The concentration dependency of apparent viscosity (η₅₀) increased with the temperature increment. The combined Power-Arrhenius model had a high coincidence in order to show the influence of concentration-temperature on η₅₀ (R² = 0.997, RMSE = 0.040). It can be concluded that the rheological properties of Iranian peach concentrates are remarkably influenced by the temperature and concentration. Among the juice, peach juice has high popularity and in terms of nutrition also has been highly regarded. Iranian peach puree is one of the main sources of peach juice production in Iran. In this research, steady shear flow behavior of peach concentrate produced from this puree were investigated at the concentration of 5, 10, 15, 20 and 25 °Bx. and temperature of 5, 25, 45 and 65 °C. The shear stress-shear rate data obtained for the concentrates were fitted by different rheological models including Newtonian, Power law, Bingham and Herschel-Bulkley. In addition, the concentration dependency was investigated by power law and exponential models and the temperature dependency was evaluated by the Arrhenius-Eyring model. All the samples showed pseudoplastic behavior. Power law model (Ostwald-de Waele’s model) with high determination coefficient (R² = 0.934-0.999) and low root mean square errors (RMSE = 0.027-0.327) had the best fit to the experimental data. It was observed that increase in the temperature leads to an increase in the flow behavior index (<em>n</em>) and a decrease in the consistency coefficient (<em>k</em>). On the other hands, increasing the concentration decreased <em>n</em> and increased <em>k</em> values. Power-law model also predicted the concentration dependency of apparent viscosity (η₅₀) with a high precision. The concentration dependency of apparent viscosity (η₅₀) increased with the temperature increment. The combined Power-Arrhenius model had a high coincidence in order to show the influence of concentration-temperature on η₅₀ (R² = 0.997, RMSE = 0.040). It can be concluded that the rheological properties of Iranian peach concentrates are remarkably influenced by the temperature and concentration. https://jift.irost.ir/article_282_48ea558a910a19705d153e7917813a0a.pdf