Microbial flora and some chemical properties of ersho, a starter for teff (Eragrostis tef) fermentation

Abstract

Ersho is a clear, yellow liquid that accumulates on the surface of fermenting teff-flour batter and is collected to serve as an inoculum for the next fermentation. The pH of ersho samples was about 3.5 and titratable acidity ranged between 3.1% and 5.7%. The mean aerobic mesophilic counts from four households varied between 6.9×10(6) and 1.3×10(8) c.f.u./ml and the aerobic bacterial flora consisted of Bacillus spp. Mean yeast counts ranged between 5.2×10(5) and 1.8×10(6) c.f.u./ml and comprised, in order of abundance, Candida milleri, Rhodotorula mucilaginosa, Kluyveromyces marxianus, Pichia naganishii and Debaromyces hansenii. Candida milleri was the most dominant isolate in all samples. About 90% of the teff flour samples had aerobic mesophilic counts ≥10(5) c.f.u./g and Gram-positive bacteria constituted about 71% of the total isolates. About 80% of samples had Enterobacteriaceae counts of 10(4) c.f.u./g.