Investigation of the Effect of Different Factors on the Thermal Properties of Barberry Puree

Abstract

For a precise design of thermal processes, the determination of the thermal properties of foods is necessary. In this study, the thermal properties of barberry puree with five moisture content (25, 30, 35, 40 and 45%), different temperature (25, 35, 45, 50 and 55ºC), salt content (0, 0.5, 1, 1.5 and 2%), and sugar content (0, 10, 15, 20 and 25%) are measured. Results showed that all factors have a significant effect on the specific heat and thermal conductivity of barberry puree. Observations showed that the increase of temperature and the increase of the moisture content resulted in increasing the special heat of barberry puree. Data showed an inverse relationship between the salt percentage and the sugar content of the barberry puree and the specific heat of this product. According to this study, the thermal conductivity of barberry purée is affected by the salt and sugar percentage added to the formulation. The higher the percentage of added salt or sugar resulted in the reduction of the thermal conductivity of barberry puree. For the prediction of the effect of moisture, temperature, salt, and sugar content on specific heat and thermal conductivity, regression models are chosen. The Coefficient of Determination (R2) of the specific heat for temperature, moisture content, salt content, and sugar content were 0.908, 0.909, 0.988, and 0.821, respectively. The Coefficient of Determination (R2) of the thermal conductivity for temperature, moisture content, salt content, and sugar content were 0.789, 0.938, 0.969, and 0.830, respectively. According to the results, the increase of temperature and moisture content resulted in increasing the magnitude of specific heat and thermal conductivity. Inversely, increasing salt content and sugar content in barberry puree formulation caused decreasing specific heat and thermal conductivity.