PREDICTION OF MOISTURE CONTENT OF GRAINS DURING RE-WETTING PROCESS FOR MILLING

Abstract

The main objectives of the present research work were to study the effects of moisture content on some characteristics of grains, the method could be used by grain industry to sequence be have moisture content during re-wetting processing and to predict moisture content by calibration of electric resistance of grains to increase grain quality in order to minimize grain.Corn variety 10, Wheat variety Giza 168 and Rice variety Sakha 103 grains were used in the experiments as re-wetting process and measurements.Grains were with the initial moisture content of about 12.5% , 12% and 11% (b.d) for corn, wheat and rice grains.The grains were milled using hammer mill. The following most tmprtant results conclusions were found, 1) The suitable moisture content was 16, 15.5 and 16.5 % of corn, wheat and rice grains, respectively at about 1.5 h of re-wetting time. Which lead to increase weight of 1000 grains was 470, 43 and 26 g , and water absorbed of grains were 0.0279, 0.0023 and 0.0017g. Meanwhile, the electric resistance of grains was decreased, which were 35.95, 35.1 and 32.2 Omme and terminal velocity was 70.5, 45.9 and 28.9 m/s, and hardness of grains was decreased, which was 189, 37.5 and 24 N of corn, wheat and rice grains, respectively 2) By increasing the moisture content of corn, wheat and rice grains during re-wetting process. The weight and water absorbed were increased. Meanwhile, the hardness and electric resistance were decreased. 3) The correlation factor between the moisture content and electric resistancewas 0.98, 0.97 and 0.97 for corn, wheat and paddy rice grains during re-wetting process, respectively. That is mean the correlation factorwas ranged between r = 0.97 – 0.98 which is considered that the correlation relationship between the moisture content and electric resistance more significant and high. 4)Re-wetting process before the grinding lead to reduction percentage of consumption energy about 20 % of grains and 5) re-wetting of grains can be important for the milling process and softens the endosperm to increase flour extraction and reduces the power consumption during the milling process.