Effect of natural fermentation on nutritional and antinutritional factors of tef (Eragrostis tef)

Abstract

Abstract: Tef flour mixed with water in a 1:1.6 (w/v) ratio was allowed to ferment at 220 C for 96 hrs by the action of endogenous microflora in the batter. After 96 hrs total protein content in tef dough decreased by 12% whereas the NPN, free amino acids, free amino acid nitrogen, soluble protein and fat acidity increased 7.4-, 7.0-, 6.6-, 7.7- and 10.7- fold, respectively. Fermentation also resulted in significant drop in pH and sharp rise in titratable acidity of the 96 hrs fermented dough. Iron, phosphorus and calcium decreased by 43%, 35% and 41%, respectively, in the dough fermented for 96 hrs. Phytic acid, tannins and trypsin inhibitor contents were reduced by 72%, 55% and 69%, respectively. In ersho, the liquid portion drained off from the fermented dough, total protein, NPN, free amino acids, iron, calcium and phosphorus increased significantly whereas total and reducing sugars decreased during the two days of fermentation. The pH of ersho dropped slightly but the titratable acidity increased by 35%. These results could provide useful indices for the improved evaluation of tef fermentation. [Ethiop. J. Health Dev. 1997;11(1):61-66]