2.2. Fermentation
Fermented dough was prepared in the traditional way. Natural fermentation was carried out by mixing sorghum flour with sterilized dionized water and other ingredients (onion, garlic, lemon juice and fenugreek) in a 1:0.8 (w/w) ratio (traditionally known as ajeen). The dough was incubated at 37 °C for 24 h in sterilized covered beaker. Two consecutive fermentations were carried out using 3% inocula (traditionally called shetiah) from a previous fermentation to start each subsequent batch. Each fermentation was performed in duplicate and sampled every 6 h during the fermentation period (24 h). Samples were dried in a vacuum oven at 50 °C (Heraucus LBS Co.) the dried samples were milled to fine powder using a coffee miller, then passed through a 60mm mesh and kept at 4 °C in polyethylene bags for analysis.