Quality evaluation of powdered ogi produced from maize-sorghum and soybean flour blends in Nigeria

Abstract

Ogi is a fermented cereal porridge usually made from single cereals such as maize (Zea mays). In traditional production, it is sometimes combined with other cereals such as sorghum or millet. It is usually in semi-solid form after production and has low shelf stability. This study was carried out to produce and evaluate the quality of ogi powder from mixtures of selected cereals (maize and sorghum), with soybean inclusion as advancement for improving the nutritive value of the product. Ogi flour was obtained from grains of maize and sorghum by weighing, sorting, soaking (for 72 hours), wet milling, sieving, dewatering, oven-drying, pulverizing and sieving through muslin cloth with maximum pore size of 20 mm. Optimal blend (70:30) for maize - sorghum ogi cumulating to 100% maize - sorghum mixture was obtained from a preliminary study; and fortified with soybean in the ratios of 90:10, 80:20, 70:30, 60:40, 50:50, and 100:0. The samples were analyzed for functional, proximate and micronutrient properties using standard methods. Results of water absorption and swelling capacity showed significant (p<0.05) differences among the samples. Proximate composition results showed significant (p<0.05) differences in all samples and ranged as follows: moisture (5.39 - 7.72%), protein (6.22 - 21. 46%), ash (2.66 - 3.64%), crude fibre (2.22 - 2.65%), crude fat (4.22 - 10.22%) and carbohydrate (51.31 - 79.14%). The micronutrient levels were improved and ranged from 166 - 360 mg/100g calcium, 1.15 - 3.22 mg/100g iron, 24.3 - 47.6 IU ß-carotene and 0.59 - 0.89 mg/100g thiamine. Soybean addition generally improved the quality of the samples. Protein increase was observed from 20% inclusion of soybean. The maximum inclusion level of 50% increased the protein content of the sample to 21.5%. Despite adding value and variety to ogi meal due to its powdered form, fortifying maize-sorghum ogi with soybean would reduce the problem of malnutrition especially among children who are usually fed ogi as infant formulae in developing countries.