Improving Nutritive Value of Fermented Cereal Porridge ‘Ogi’ by Fortifying with Bambara Nut

Abstract

Ogi, a fermented cereal porridge made from maize (Zea mays), sorghum 
\n(Sorghum vulgare) or millet (Pennisetum typoideum), experiences nutritional 
\nloss during traditional method of production. Hence, this study was undertaken 
\nto improve the nutritive value of ‘Ogi’ by fortifying with Bambara nut, a 
\nnutritious legume rich in carbohydrate, moderate protein and low fat. 
\nFortification ratio of Bambara to the commonly known substrates (maize, millet 
\nand sorghum grains) was 2:3 while the control was constituted with equal 
\nquantity of substrate without Bambara. Traditional process including steeping, 
\ngrinding, sieving and souring was used. Microbiological and physicochemical 
\nanalysis were carried out on the resulting fortified and unfortified Ogi at 0, 24, 
\n48 and 72 hours during primary fermentation and at 0, 24 and 48 hours during 
\nsecondary fermentation. Bacteria isolated include Lactobacillus fermentum, L. 
\nplantarum, Bacillus subtilis, Flavobacterium rigense, Proteus vulgaris, 
\nFlavobacterium aquantile and Bacillus alvei and the fungi include Geotrichum 
\ncandidum, G. fermentum, Penicillium atrovene, Aspergillus niger, Rhizopus 
\noryzae, etc. Reduction in pH of the fermenting substrates was noticed as 
\nfermentation progressed and this was accompanied with increase in total 
\ntitratable acid (TTA) in all cases. Temperature was constant at 30 ± 2 °C. 
\nProximate analysis of the final products revealed that more than 100% nutrient 
\nimprovement in protein composition in fortified Ogi from sorghum and maize 
\nand 53.82% nutrient improvement in fortified Ogi from millet. There is also 
\nincrease in the fat content of the fortified Ogi from sorghum, maize and millet 
\nby 38%, 57% and 174% respectively. Fortifying these cereals with Bambara nut 
\nalso improved the ash content of sorghum and maize ‘ogi’ by 23.89% and 
\n15.33%. The organoleptic assessment designed to measure appearance, 
\nsourness, flavour, taste, aroma/smell, acceptability and comparability among 32 
\nuntrained panellists at overall acceptability at 5% confidence level revealed that 
\nfortified Ogi made from maize was the most acceptable.