Modeling of particle size distribution and energy consumption of wet milled maize at varying soaking period and method in the production of Ogi

ABSTRACT

Energy consumptions and particles size distribution of soaked maize grains at varying time were studied and modeled. Rosin–Rammler–Bennet (RRB) model well fitted first milling size distribution with a high coefficient of determination (R²) and low root mean square error (RSME). The milling energy of maize grains decreased significantly (p < 0.05) with increase in soaking time. The milling energy decrease from 32 to 8.72 kWh/kg and 32.00 to 9.00 kWh/kg for maize variety E9W at 24th hour soaking conditions of 28 and 65°C, respectively. Similar observations for A4W, B2Y and C3Y at 24 h of soaking were recorded. The Work index, Kick’s and Rittinger’s constants decreased with increase in soaking time. There was significant difference (p < 0.05) in values obtained for Bond work index, Rittinger’s and Kick’s constants; these decreased with increase in soaking time. Predicted energy consumption followed similar trend. The interaction effect between energy consumption, Moisture content, and Milling time showed a high R² (0.8767–0.99349); while the regressed model for determining energy consumption from relationship between the mass, moisture content, milling time and the ratio of the geometric diameter mean and final size of the product were also established in this work with R² ranging from 0.9355 to 0.967.

KEYWORDS:

• Energy consumption
• milling
• moisture
• particle size distribution
• soaking