Selection, use and the influence of starter cultures in the nutrition and processing improvement of ogi
Author(s): Olakunle David Teniola, Wilhelm H Holzapfel, Sunday Ayodele Odunfa
The selection criteria of starter cultures (SCS) used for ogi production were reported. These SCS were used with the aim of improving processing technique, and lysine and methionine levels of ogi, a lactic acid fermented weaning food limiting in these two amino acids. Lactobacillus brevis XO43 and Saccharomyces cerevisiae OY4 were used as SCS in a pilot plant study. Fermentation with SCS showed a constant final pH level of 3.35 in modified substrates after fermentation unlike spontaneously fermented; and significantly higher acidity (%TTA) indicative of faster fermentation. The addition of sugar (2% w/w) and soybean flour (1% w/w) also increased the acid levels during fermentation. Fermentation of dehulled maize (DM) grains fortified with glucose (2%w/w) alone by SCS shows the best quality in all the parameters considered except the available niacin yield. The lysine is 24% higher than oven-dried ogi flour from the traditionally fermented (TF) and 11% higher than unprocessed whole maize grains (WMG). The methionine is 92% and 77% higher than the TF ogi and WMG, respectively. The total amino acids level of the sample was 32% more than the TF ogi flour and 55% more than WMG. Although, the soluble protein level was 23% lesser than the unfermented WMG, it was 12% more than the DM substrate and ogi from TF. Fermentation of corn into ogi led to losses in the initial quantity of niacin. SCS significantly improve the nutrients such as lysine, methionine, total amino acids, soluble protein and niacin more than spontaneous fermentation. Dehulling of grains, dewatering and oven drying significantly reduce nutrients. Ogi fermentation process with the use of SCS and DM guarantee organoleptic qualities, improve ogi production by eliminating wet-sieving, limiting water usage, and creating better nutritional products.