A comparative study of physical properties of selected rice varieties in Nigeria

Abstract

Rice is now the main food for about 35 million people in Nigeria, and consumption is increasing faster than that of any other food crop in many countries in Africa. This study provided essential engineering data on the physical properties of selected varieties of local rice in Nigeria. Some selected physical properties of Igbemo, Ofa- da and Abakaliki rice varieties at harvest, market, and storage conditions were evaluated as a function of moisture content. The latter ranged from 12.38 to 25.69% (dry base). We also determined the physical properties of the rice samples, such as moisture content, linear dimensions, geometric mean diameter, arithmetic mean diameter, surface area, aspect ratio, sphericity, bulk density, and hundred kernel weights. A result of the linear dimensions for the major diameter was 8.4–10.3 mm, 6.4–6.55 mm, and 5.9–7.4 mm for harvested, marketed, and stored rice, respec- tively. The minor diameter ranged from 2.70 to 3.29 mm, 2.49 to 2.63 mm, and 2.56 to 2.74 mm, and the intermedi- ate diameter of the rice varieties at harvest, market, and storage conditions was 1.92–2.29 mm, 1.90–2.02 mm, and 1.87–1.99 mm, respectively. Depending on the conditions and varieties, the bulk density, true density, and porosity, was observed to be between 0.59 to 0.90 g/cm3, 2.28 to 5.57 g/cm3 and 70.38 to 85.35% respectively.