Effect of levels of Bacillus subtilis and Bacillus licheniformis used singly or in combination as inoculum on pH and titratable acidity (TA) development during soybean fermentation for dawadawa production were investigated. Soybean seeds were processed and then fermented with 0.01%, 0.025%, 0.05%, 0.075% and 10% levels of B.subtilis and B. lichenformis inoculum in singles or in combination. The results showed that there was a significant increase (p<0.05) in titratable acidity values at all the levels of B. subtilis and B. lichenformis used singly or in combination as inoculum. Fermentation time and inoculum levels as titratable acidity changes resulted in significant increase in titratable acidity. Fermentation of soybean with B. licheniformis showed that inoculum levels (0.01%, 0.025%, 0.05%, 0.075%, 0.10%) used as titratable acidity changes were not significant (p<0.05). pH values increased significant (p<0.05) at all levels of Bacillus spp used singly or in combination. Fermentation time and inoculum levels (0.01%, 0.025%, 0.05%, 0.075%, 0.10%) used for B. subtilis were significant (p<0.05). There was no significant difference in the product quality attributes based on inoculum type and levels used as evaluated by sensory panelists. Therefore, dawadawa could be produced using either B. subtilis or B. licheniformis.
(Global Journal of Pure and Applied Sciences: 2003 9(2): 205-212)