This study evaluated the thermo-physical and rheological properties of Ogi produced from varieties of sorghum with different soaking period (12, 24 and 36 hrs.). Sorghum grain steeped for 12, 24 and 36 hrs. was processed into Ogi making use of the traditional method and subsequently dried at 55oC. The Ogi powder obtained was analyzed for functional, thermo-physical, rheological properties and the consumer acceptability was also carried out. The results showed that the bulk density ranged from 0.80 – 0.90g/ml, respectively from all the steeping periods and varieties. Water absorption capacity and Oil absorption capacity (198.33 - 251.00 g/ml) and (112.33-146 g/ml), respectively. Swelling power and solubility ranged from 7.88 - 9.97g/g and 5.76 - 21.83%. Amylose and moisture content 12.59 - 23.92 % and 8.00-12.05% respectively. Results revealed that a significant difference (P<0.05) in all the functional properties .The viscosity results at 90oC and rpm 3.0, 6.0, 12.0, 30.0, 60.0 are (1379.4 -1725.9), (772.9 -1110.9 Mpa), (449.2-623.3 Mpa), (230.4 -306.4 Mpa) and (96.6-152.7 Mpa), respectively. At 80oC and rpm 3.0, 6.0, 12.0, 30.0, 60.0 are (1277.0 - 1647.6 Mpa), (720.1 - 928.7 Mpa), (412.4 - 538), (223.5 - 277.8 Mpa) and (94.5 - 158.5 Mpa), respectively. At 70oC and rpm 3.0, 6.0, 12.0, 30.0, 60.0 are (1310.0 - 1645.8 Mpa), (713.0 - 887.8 Mpa), (412.8 - 516.8 Mpa), (211.2-270.8 Mpa) and (84.7-165.5 Mpa), respectively while the red sorghum Ogi had the highest viscosity value. The density, specific heat capacity, thermal conductivity, thermal diffusivity was evaluated the result are (1.20- 2.00), (5.357 and 9.643), (1.192 - 2.0695wm/k) and (0.671 and 1.970 m2/s ) respectively. The research showed that thermo-physical properties are affected by moisture content of sorghum Ogi. The Ogi porridge was evaluated for taste, colour, texture, aroma and overall acceptability by a 10 member panelist and analyzing the data using ANOVA. No significant difference (P>0.05) was found among the samples for overall acceptability. Data collected from all experiments were in triplicate, and subjected to statistical analysis, using analysis of variance (ANOVA).
