Fermentation dynamics of spontaneously fermented Ethiopian honey wine, Tej

Spontaneously fermented Ethiopian honey wine, Tej, is a popular alcoholic beverage in Ethiopia. However, a detailed information which is needed to modernized the production process of this traditional beverage has not yet been conducted. Thus, this paper is aimed to reveal the physicochemical and microbial dynamics occurred during Tej fermentation processes. To address this objective, Tej samples was collected every 48 h from three households located at three different cities of Ethiopia. As fermentation progressed, pH, glucose, and fructose content decreased, whereas, titratable acidity and alcohol content increased. Likewise, antioxidant activity, especially 3-ethylbenzothiazoline-6-sulfonic acid diammonium salt (ABTS) assay, increased as the fermentation progressed to final stages. Moreover, the bacterial communities shifted to Lactobacillus dominancy as the fermentation progress to the end. Furthermore, during the whole fermentation period, fungal communities were practically dominated by Saccharomyces species. Due to these dominances microbial diversity decreased toward the end of fermentation. Besides, quantitative increases in both microbial communities were observed during Tej fermentation periods. However, fungal gene copy numbers were by half higher than bacterial gene copy numbers. In conclusion, Species of Lactobacillus and Saccharomyces could be taken as a potential mixed starter culture candidates for inoculated Tej fermentation systems.