Thermophysical properties of lemon juice as affected by temperature and water content

Abstract

To design equipment for food processing and estimate process times for refrigerating, freezing, heating, or drying of foods, the thermophysical properties must be known. Since the thermophysical properties of foods are strongly dependent upon chemical composition and temperature, composition and temperature based models provide a means of estimating these properties. In this work, the thermophysical properties of lemon juice were determined at a water mass fraction of (0.381 to 0.900) and a temperature of (273.45 to 353.75) K. Density and thermal conductivity varied from (962.3 to 1282.8) kg·m−3 and (0.344 to 0.624) W·m−2·K−1, respectively. Heat capacity and thermal diffusivity varied from (2446.5 to 4060.1) J·kg−1·K−1 and (0.1160·10−6 to 0.1785·10−6) m2·s−1, respectively. Simple polynomial functions were fitted to the experimental data, and good agreements were obtained. In the tested range, water content showed greater influence on the thermophysical properties.