Some Physical Properties of Amaranth Seeds

Several physical properties of amaranth seeds (Amaranthus cruentus) were evaluated as a function of moisture content. When moisture content changed from 7·7 to 43·9% d.b., true density decreased from 1390 to 1320 kg m−3, bulk density from 840 to 720 kg m−3, specific volume increased from 0·78 to 1·10×10−3 m3 kg−1 and porosity varied from 0·40 to 0·45. Shrinkage coefficient was found to be 1·25. By means of image analysis, relevant dimensions were measured as a function of moisture content. In the moisture content range of 9·5–43·6% d.b., the average length, width and thickness were 1·42, 1·29 and 0·87 mm, respectively. The geometric mean diameter of seed ranged from 1·10 to 1·24 mm, whereas mean sphericity was 0·82. The average pycnometric volume and area of one grain were 0·65 mm3 and 3·96 mm2, respectively.