Physical properties of acerola and blueberry 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 353 K, varies between 0.97 and 1.03 kg m⁻³; for blueberry it ranged between 0.98 and 1.05 kg m⁻³. Electrical conductivity was between 1.69 and 8.48 mS cm⁻¹ for acerola pulp and between 0.79 and 3.86 mS cm⁻¹ for blueberry. Specific heat, thermal diffusivity and thermal conductivity of acerola pulp at approximately 313 K showed values of 4172.49 J kg⁻¹ K⁻¹, 1.53 × 10⁻⁷ m² s and 0.65 W m⁻¹ K⁻¹, respectively. For blueberry, these values were 4050.39 J kg⁻¹ K⁻¹, 1.51 × 10⁻⁷ m² s and 0.64 W m⁻¹ K⁻¹.