Optimization of processing conditions of Ogi produced from maize using response surface methodology (RSM)

Effect of processing conditions involving soaking time (12–36 h) and sedimentation time (6–18 h) on pH, Total titirable acidity (TTA), Viscosity at 60 rpm and sensory evaluation ogi (pap) were evaluated and optimized by response surface modelling. A central composite rotatable experimental design with two factors and five levels (−1.414, −1, 0, 1 and 1.414) was used. The results revealed that the pH, TTA and viscosity at 60 rpm reduced with increase in soaking and sedimentation time. There was no significance difference (p > 0.05) in the value obtained for sensory evaluation, however, these ranged from 2.60–3.87 (Aroma), 2.47–3.87 (Taste), 2.60–4.67 (Colour) and 2.60–4.07 (Consistency), respectively. The predicted optimum soaking and sedimentation time were 16 and 8 h, respectively. The desirability value was 0.99. This research suggests ogi production with desired qualities, is achievable at total time of 24 h. Also, varying the soaking and sedimentation time have tendency to affect the quality of ogi.