Influence of Saccharomyces cerevisiae (Baker’s Yeast) on the Fermentation of Ogi-A Nigerian Fermented Food

Abstract

Ogi is a traditional fermented food produced from maize and serves as breakfast food for the majority of the population and is a good food choice for the sicks. Locally produced Ogi varies in its quality and shelf life because it is produced without any starter culture. In order to standardize ogi production there is need to use appropriate starter culture for ogi production. In this work influence of processing method and the use of Saccharomyces cerevisiae (S. cerevisiae) on quality attributes of ogi samples was investigated. Maize samples soaked in water for two days were allowed to germinate. The sprouted and unsprouted maize samples were wet milled and then inoculated with yeast S. cerevisiae. The samples were then fermented, and physico-chemical and microbiological changes was determined during fermentation. There was significant drop in the final pH values of the four preparation from changes 5.65 down to 3.51. Mean while, respective titratable acidity (TTA) increased on average from 0.175 up to 0.220 g/L. The total viable count of yeasts increases from 9.80 x 107 to 1.26 x 1014 cfu/mL. While, the fungal count increased within narrow ranges from 3.0 X 107 up to 3.2X1013 cfu/mL. The coliform counts were reduced steadily and completely disappeared after 48 hours of fermentation. The four ogi preparations were quite high in their moisture contents (7 0 - 76.5%). The crude protein contents fluctuated between 1.82 and 5.47% in the (4) ogi products. This work showed that ogi prepared from unsprouted maize grains and without yeast fermentation ranked highest with regard to highest protein content and sensory evaluation and received overall acceptability of 7.