Physical properties of acerola and blueberry pulps

• Published in: Journal of food engineering Vol. 106; no. 4; pp. 283 - 289
• Main Authors: Mercali, Giovana Domeneghini, Sarkis, Júlia Ribeiro, Jaeschke, Débora Pez, Tessaro, Isabel Cristina, Marczak, Ligia Damasceno Ferreira
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-10-2011; Elsevier
• Subjects: Biological and medical sciences; Blueberries; Density; Electrical conductivity; Electrical resistivity; Food engineering; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; General aspects; Mathematical analysis; Physical properties; Resistivity; Specific heat; Thermal conductivity; Thermal diffusivity; Specific heat; Thermal diffusivity; Thermal conductivity; Electrical conductivity; Density; Fruit; Berry; Physical properties; Pulp; Vaccinium; Dicotyledones; Blueberry; Angiospermae; Spermatophyta; Ericaceae
• ISSN: 0260-8774; 1873-5770
• DOI: 10.1016/j.jfoodeng.2011.05.010

► Knowledge of thermophysical properties of food is required for a wide variety of research and engineering applications. ► Some physical properties of acerola and blueberry pulps were determined. ► The results obtained are close to the thermophysical properties of water due to the high moisture content of the samples. ► These data can be used for modeling, simulation and optimization of food-processing operations involving fruit pulps.
In this work, some physical properties of acerola and blueberry pulps were determined. The density was determined by the pycnometer method; the electrical conductivity using a conductivimeter; the thermal diffusivity by a method based on the analytical solution of heat diffusion equation; the specific heat capacity by a modified method of mixtures; and the thermal conductivity from the knowledge of other properties. Results showed that the density of acerola pulp, in the temperature range between 303 and 353K, varies between 0.97 and 1.03kgm−3; for blueberry it ranged between 0.98 and 1.05kgm−3. Electrical conductivity was between 1.69 and 8.48mScm−1 for acerola pulp and between 0.79 and 3.86mScm−1 for blueberry. Specific heat, thermal diffusivity and thermal conductivity of acerola pulp at approximately 313K showed values of 4172.49Jkg−1K−1, 1.53×10−7m2s and 0.65Wm−1K−1, respectively. For blueberry, these values were 4050.39Jkg−1K−1, 1.51×10−7m2s and 0.64Wm−1K−1.