Lactic acid and volatile (C2-C6) fatty acid production in the fermentation and baking of tef (Eragrostis tef)

Abstract

As practised domestically in Ethiopia, tef flour mixed with water was allowed to ferment by the action of the endogenous microflora to produce a sour dough prior to baking to produce injera, a pancake-like bread. Lactic and acetic acids were the major organic acids produced (90 %) with seven other volatile fatty acids (VFAs), propionic, isobutyric, n-butyric, isovaleric, n-valeric, isocaproic, n-caproic representing less than 5%. Baking reduced the proportion of acetic acid but not the other VFAs. Lactic and acetic acids are mainly responsible for the fall in pH during fermentation and for the sour taste of injera, whilst the VFAs are the main contributors to the characteristic flavour.