Comparison of Engineering Properties of Raw and Roasted Cereals and Millets

摘要

The Physico-chemical properties of various raw and roasted cereals (Wheat: WH-1021, Maize; PEHM5, Barley: Ratna, Oat: Kent) and millets (Pearl millet: 1CMV221, Sorghum: Sweta, Finger Millet: IE-28) were investigated. The physical properties (length, breadth, thickness, geometric mean diameter, aspect ratio, sphericity, surface area), gravimetric properties (bulk density, true density and porosity), frictional properties (angle of repose and static coefficient of friction), and optical properties (L,a*, b*, AE) were studied for some of the varieties of cereal grains and compared between roasted and unroasted grains. The engineering properties were determined in compliance with ASAE Standard 5352.1 (1984). Results obtained showed a bulk density ranging from 992.0 in wheat to 413.2 kgW in maize, both roasted and unroasted cereal grains. The relation between length, breadth, thickness, arithmetic mean, geometric mean, volume, sphericity, bulk and true density, porosity, surface and specific surface follow a strict pattern which enables the reliable correlation of geometrical dimensions to the unit mass. The correlations could be used for sorting, conveying and hopping. The engineering and mechanical properties of various cereals and millets vary considerably. The correlation found in this study is useflil for handling, sorting and conveying purpose.