Physical properties of shelled and kernel walnuts as affected by the moisture content

Abstract

The variations in physical properties such as the size dimensions, unit mass, sphericity, projected area, bulk density, true density, volume, coefficient of friction on various surfaces, and terminal velocity of shelled and kernel walnuts as a function of the moisture content were determined. With an increase in the moisture content, the sphericity, projected area, bulk density, volume, and porosity of shelled and kernel walnuts increased, whereas the true density linearly decreased. Studies on rewetted walnuts showed that the terminal velocity increased from 14.17 m/s to 15.50 m/s, and from 12.60 m/s to 14.35 m/s, for shelled and kernel walnuts, respectively. The static and dynamic coefficients of friction of shelled and kernel walnuts on chipboard and plywood surfaces also increased linearly with an increase in the moisture content.