1 Effect of Moisture Content and Loading Orientation on the Mechanical Properties of Balanites Aegyptiaca Nuts

Abstract

Lack of an appropriate equipment to crack balanites aegyptica nuts to obtain the kernels, which are rich in oil and proteins, have limited their use and popularity. The manual method, which involves cracking with stone on top of another stone or metal, is slow and risky. In order to design appropriate processing equipment, sufficient knowledge of the mechanical properties of the different varieties is very important. The need to get sufficient information on the mechanical properties of balanites aegyptiaca nuts led to the study of the effect of moisture content and loading orientation on six mechanical properties of the one end tapered oblong and spheroidal accessions of balanites aegyptiaca (desert date) nuts. Four moisture levels and two compressive loading orientations (axial and longitudinal) were used to test the nuts of the two accessions in a universal-testing machine. The ranges of moisture content used were 4.7–26.4 % (d.b.) for the oblong accession and 4.7–24.2 % (d.b.) for the spheroidal accession. The six mechanical properties investigated were modulus of elasticity, bioyield point, bioyield stress, compressive strength, rupture strength and modulus of stiffness. Results obtained show that values of all the six properties decreased with increase in moisture