Influence of Soaking on Moisture – Dependent Physical Properties of Some Selected Grains Essential to Design of Grain Drinks Processing Machine

Abstract

The influence of soaking on moisture - dependent physical properties of some selected grains essential to design of an automatic continuous grain drinks processing machine was studied. Three grain types were used for the study, they are white maize (Zea mays), white guinea corn (Sorghum bicolor) and large seeded soya beans (Glycine max). The white maize and sorghum were soaked for 36 hours while the soya beans was soaked for 12 hours in accordance to standard procedure. The result obtained showed that moisture content level of the grains increased with increased in soaking time from 12.4% to 20.5% W.b. for corn when soaked, 1 1.3% to 20.6% W.b. for sorghum and 10.9% to 20.5% W.b. for soya beans. The entire grains dimension increased with increase in moisture content. Soya beans had the highest increased in surface area with increase in moisture level (10.9% to 20.5%) from 76.6 mm3 to 167.81 mm3 (119.07% increase), while sorghum had the least increase in surface area with increase in moisture level (11.3% to 20.6%) from 40.08 mm3 to 55.75 mm3 (39.09% increase). Furthermore, soya beans had the highest decrease in bulk density from 780.44 kg/m3 to 667.32 kg/m3 while corn had least decrease of 768.44 kg/m3 to 762.21 kg/m3 with increase in moisture level. These properties of the grains were found to be important factors to be considered in the design of the hopper, delivery tube, blending chamber and the grain reservour. The result thus, obtained fully describes the influence of soaking of the grains on their moisture - dependent physical properties that are essential to the design of grain drinks processing machine.Therefore, the knowledge of the physical properties of the grains will provide a rational approach to the design of the machine.