Moisture dependant physical and uniaxial compression properties of black pepper

Abstract

The physical and uniaxial compression properties of black pepper (Piper nigrum L.) seed at different moisture contents (8–32%, dry weight basis) were determined. The physical properties such as size, roundness, sphericity, bulk density, angle of repose and flowability, and different uniaxial compression parameters (failure force, failure strain, linear strain limit, energy for failure and deformation modulus) were determined. The roundness and sphericity values were in the neighbourhood of 1.1 and 95%, respectively, indicating a near spherical shape of the seed. An increase in moisture content increased angle of repose but decreased flowability, particularly when the moisture content was above 14% (dry basis). The deformation modulus was also sensitive to moisture content of the seed, and decreased from 44.5 to 14.1 N/mm with an increase in moisture content.