Abstract

Fermenter Technology Modification Changes Microbiological and Physicochemical Parameters, Improves Sensory Characteristics in the ermentation of Tella: An Ethiopian Traditional Fermented Alcoholic Beverage

Belay Berza and Awraris Wolde

Tella is an indigenous, a home processed and commercially available traditional fermented alcoholic beverage in Ethiopia. It is a main source of income for low-income women in Ethiopia. Tella gets easily spoiled and causes economic loss, as result; brewed in small amount while there are many users. This study investigated effects of fermenter technology modification on microbiological, pshysicochemical parameters and sensory characteristic of tella brewed in modified and traditional fermenters. Experiments were conducted using modified and traditional fermenters. Microbiological analysis was done for the fermenting mashes at 12 h interval. The physicochemical parameters consisted of pH, TA, Mash and environmental temperatures, Total carbohydrate, reducing sugar and ethanol content were determined. Sensory evaluation was performed for tella brewed in modified and traditional fermenters using Sensory attributes such as appearance and color, aroma, taste, strength (alcoholic) and overall acceptability. The counts of lactobacillus, lactococcus, yeasts and aerobic mesophilic bacteria showed increment during the first two phases in both fermenters but gradually decreased at phase IV in both fermenters. The counts of Enterobacteriaceae were high at day zero and not detected at phase II in both fermenters. Acetic acid bacteria were detected at the beginning of phase II in traditional fermenter but at phase III in modified fermenter.Total carbohydrate was 26.4 mg/ ml and 25.7 mg/ml at day zero in modified and traditional fermenters respectively and reached 77 mg/ml at phase III in modified and 78.1 mg/ml in traditional fermenter and then has shown decrement in next phases. Ethanol was detected at phase II in both fermenters and showed gradual increment with fermentation period. Aroma, taste and alcoholic strength were superior for tella brewed in modified fermenter. Using appropriate fermenter technology is important to brew tella with preferable sensory attributes, to make its brewing continuous, and generate continuous income.