Bacteriological and Physicochemical Analyses of Ogi Fermented from Zea mays, Sorghum bicolor and Pennisetum glaucum Cereals

Abstract

The study assessed the bacteriological and physicochemical parameters during the fermentation of ogi from Zea mays, Sorghum bicolor and Pennisetum glaucum cereals. Ogi was produced from white Zea mays, yellow Zea mays, Sorghum bicolor and Pennisetum glaucum cereals and was allowed to ferment by steeping in distilled water for four (4) days at a temperature of 28 ºC. The effluents generated from the steeping water were collected daily for physicochemical (pH, total titratable acidity and temperature) and bacteriological (total heterotrophic bacterial count and total lactic acid bacterial count) analyses. After the fermentation process, the steeped grains were wet milled, sieved, allowed to sediment and decanted to produce the semi-solid ogi samples. The study revealed a decrease in pH from 6.83 to 4.40, an increase in total titratable acidity from 0.07 to 1.85g/L and an increase in temperature from 26.33 to 31.33ºC. There was an increase in the total heterotrophic bacterial count from 2.5×105 to 63.5×109 and in the total lactic acid bacterial count from 5.0×103 to 98.5×108 during fermentation. Bacteria belonging to the genera Enterobacter, Erysipelothrix, Pediococcus, Weisella, Veillonella, Proteus and Bacillus were present during the fermentation of ogi from white and yellow Zea mays, Sorghum bicolor and Pennisetum glaucum cereals. The study revealed high microbial populations, the presence of lactic acid bacteria and stable physicochemical conditions during the fermentation of white and yellow Zea mays, Sorghum bicolor and Pennisetum glaucum cereals to ogi.