MICROBIOLOGY OF THE FERMENTATION OF SHAMITA, A TRADITIONAL ETHIOPIAN FERMENTED BEVERAGE

Abstract

Shamita is a low-alcohol traditional beverage made by overnight fermentation of mainly roasted barley flour and consumed as meal-replacement. The microbiology of shamita was studied using several general, selective and differential media. All ingredients and the clay jar rinse water had large numbers (> 104 colony forming units (cfu) per gram or millilitre) of aerobic mesophilic bacteria (AMB) made up mostly of Bacillus spp. and micrococci. Barley malt
contributed most of the lactic acid bacteria (LAB) and yeasts which were most important to the fermentation and dominated the fermentation flora reaching final counts of 109 and 101 Cfu(mlyl, respectively. Heterofermentative and homofermentative Lactobacillus spp. were the major groups of LAB isolated from the fermenting shamita. The pH dropped from an initial value of 5.80 to 4.03 over the 24 h period of fermentation. Coliforms and other members of Enterobacteriaceae
as well as moulds were eliminated after 16 h fermentation. Laboratory prepared shamita had comparable microbial counts with samples
collected from local shamita brewers in Addis Ababa.