Impact of Starter Culture Fermentation on the Nutritive Quality of Multigrain Ogi Enriched with Tigernut Flour

Abstract

'Ogi', is a product of the fermentation of cereal(s), either maize (Zea mays), sorghum (Sorghum vulgare), or millet (Pennisetum glaucum), or combination of cereals. There is nutrient loss during traditional methods of production, resulting in low protein content. The addition of protein-rich foods such as Tigernut (Cryperus esculentus), can improve the nutrients. This study focused on ameliorating nutrient loss observed during the fermentation process of ogi, with the addition of protein-rich tigernut. Eight samples were prepared from multigrain and tigernut flours (100:0; 70:30; 60:40; and 50:50). One batch was spontaneously fermented (SPF) while starter culture fermented (SCF) was included in the second batch. Lactobacillus bulgaricus, Streptococcus thermophilus and Lactobacillus acidophilus microorganisms in yoghurt starter culture was used to ferment the cereals. Physicochemical properties, nutritional, sensory, and microbial content were determined. The pH of samples ranged from (1.9 to 3.5). During sensory evaluation, panelists preferred 100:0 and 70:30 spontaneously fermented (SPF) and starter culture fermented (SCF) ogi’ samples and were selected for further analyses. Moisture (%) range was (2.47±0.01 to 2.68±0.04), protein (28.4±0.3 to 31.66±0.2), ash (4.88±0.09 to 5.79±0.04), fibre (5.95±0.6 to 8.53±0.3), fat (6.7±1.1 to 8.3±0.2). Calcium ranged from (126.9±0.5 to 151.4±0.1), potassium (148.7±0.3 to 172.5±0.5), magnesium (54.1±0.6 to 91.5±0.1), phosphorous (75.2±0.1 to 89.7±0.1) and lead (0.03±0.0 to 1.1±0.01) (mg/kg). The total viable count, Enterobacteriaceae and fungal counts ranged from (7.9×107 to 2.9×108 CFU/mL), (1.6×104 to 1.9×105 CFU/mL), and (1.5×107 to1.5×108 CFU/mL) respectively. Nutrient composition of ogi was improved upon by the addition of tigernut and fermented with starter culture.