ABSTRACT

This research was aimed at designing an industrial process for fermentations of maize to produce ogi by inoculating lactic acid bacteria. Changes in pH, temperature and titratable acidity (ITA), as well as the diversity of lactic acid bacteria species were investigated during both fermentations. Lactic acid bacteria strains involved in the fermentation processes were isolated at 24 hour intervals, characterized and identified using phenotypic and biochemical methods. A rapid decrease in pH, 5.4 to 4.3 were observed with temperature increasing from 29°C to 31°C. Most of the lactic acid bacteria strains isolated were homo-fermentative and hetero-fermentative Lactobacillus plantarum, Lacto bacillus brevis and Lactococcus. lactis were dominant in maize fermentation. The dominant strains can serve as potential starter cultures in ogi production. Lactic acid bacteria counts varied during the fermentation of the cereals while the titratable acidity (TTA) increased with reduction in pH. The potential of the isolates as starter cultures was determined by inoculating pure culture of lactic acid bacteria on sterilized cereals. The pH of the inoculated sterilized cereals dropped steadily while the total viable counts of the lactic acid bacteria especially L. plantarum increased. This study showed potentials of L. plantarum as a starter culture for industrial fermentation of maize for 'Ogi' production. The assessment of the performance of each of the species under controlled fermentation will enable selection of the best strains that can serve as potential starter culture for the production of microbiologically stable and predictable end products