Effect of soaking time and drying temperature on the quality of Ogi powder produced from biofortified maize

Ogi is a traditional fermented cereal-based weaning food or adult gruel produced from cereals like maize. Ogi produced from biofortified maize contains significant amounts of β-carotene, a precursor for vitamin A, which will help to tackle vitamin A deficiency. This research aimed to evaluate the effect of soaking time and drying temperature on the quality parameters of biofortified Ogi flour. Soaking was done at different times (24, 48 and 72 h) while drying was done using two drying methods, sun drying and oven drying (40°C, 50°C, and 60°C). Proximate composition, carotene, total titratable acidity and pH values were determined, functional properties like bulk density, swelling index, oil and water absorption capacities and dispersibility were determined. The moisture, ash, protein, fat and carbohydrate contents were in the range of 8.55–11.53%, 1.44–6.92%, 6.15–7.06%, 3.50–16.83%, and 63.06–74.57%, respectively. The carotene, TTA, and pH ranged from 13.57 to 33.75 µg/100 g, 0.33–0.93%, and 3.57–4.90 respectively. The loose and bulk density values ranged from 0.28 to 0.39 g/mL and 0.44–0.67 g/mL, respectively. Swelling index ranged from 1.30 to 1.70 g/g, oil absorption index from 0.85 to 1.12 g/g, water absorption index from 0.37 to 1.08 g/g, and dispersibility from 56.00 to 65.00. Swelling power and solubility index increased with increasing temperature, showing typical starch behavior. Sensory scores for appearance, texture, flavor, taste and the overall acceptability were ranged from 4.38 to 8.07, 5.13–7.00, 5.00–7.13, 4.88–6.94, 5.21–7.00. The sample soaked for 48 h and dried at 60°C (oven drying) exhibited the highest carotene retention (33.75 µg/100 g) and the highest overall sensory acceptability. Therefore, biofortified Ogi flour should be promoted as a means of achieving food and nutritional security.