Development of mixed starter culture for the fermentation of Ethiopian honey wine, Tej.

Ethiopian honey wine is one of the country's most popular spontaneously fermented traditional alcoholic beverages. However, the final product of this natural fermentation system is frequently of poor and inconsistent quality. Furthermore, it makes the process difficult to predict, control, and correct. Thus, the main aim of this study was to develop a direct fermentation system for Ethiopian honey wine, Tej. After isolating fermentative microbial strains from Tej samples, they were subjected to intensive screening to fit to its purpose. Later, phenotypic and genotypic characterization, and inoculation of isolates to honey-must were performed sequentially. Finally, microbial interaction and physicochemical analysis, including volatile compounds profiling, were done for the inoculated samples. The identified isolates were strains of Saccharomycetaceae and Lactobacillaceae families. These strains showed a good ability to tolerate osmotic stress and a lower pH environment. Tej sample produced by mixed culture inoculation of Saccharomyces and Lactobacillus species showed similar physicochemical, volatile compounds, and sensory attributes values with that of the control sample. Thus, a mixture of Saccharomyces and Lactobacillus strains could be used as a starter culture to produce Ethiopian honey, Tej, without scarifying of its major quality attributes.

Microbiome dataset of spontaneously fermented Ethiopian honey wine, Tej.

This dataset contains raw and analyzed microbial data for the samples of spontaneously fermented Ethiopian honey wine, Tej, collected from three locations of Ethiopia. It was generated using culture independent amplicon sequencing technique. To gain a better understanding of microbial community variance and similarity across Tej samples from the same and different locations, the raw sequenced data obtained from the Illumina Miseq sequencer was subjected to a bioinformatics analysis. Lower diversity and richness of both bacterial and fungal communities were observed for all of the Tej samples. Besides, samples collected from Debre Markos area showed a significant discriminating tax for both bacterial and fungal communities. In nutshell, this amplicon sequencing dataset provides a useful collection of data for modernizing this spontaneous fermentation into a directed inoculated fermentation. Detail discussion on microbiome of Tej samples is given in [1].

Physicochemical properties, antioxidant activities and microbial communities of Ethiopian honey wine, Tej.

Ethiopian honey wine, Tej, is spontaneously fermented traditional alcoholic beverage, usually made from honey and "gesho" (Rhamnus prinoides). Till now, limited amount of information is available on the characterization of Tej. Thus, the aim of this paper is to reveal the microbiological diversity and physicochemical properties of Tej samples collected from different areas of Ethiopia. High-throughput sequencing, electrochemical and chromatographic techniques, and spectrophotometric methods were used to achieve these objectives. Although there was a statistical difference in the exact values of physicochemical properties between the collected Tej samples, the pH and titratable acidity values of the samples ranged from 2.8 to 3.8 and from 1.81 to 8.65 g/L, respectively. Similarly, the alcohol and sugar contents of the samples were in the range of 6.36-11.34 g/100 mL and from 0.37 to 31.6 g/L, respectively. Moreover, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 3-ethylbenzothiazoline-6-sulfonic acid diammonium salt (ABTS) values of the samples were in the range of 37.9-81.0% and 27.4-73.1%, respectively. Furthermore, microbial community structure was predominated by a few fermentative microorganisms. Specifically, the bacterial community structure was dominated by the genera of Lactobacillus (53.15%) and Zymomonas (38.41%). Whereas, the fungal community structure was exclusively dominated by genus of Saccharomyces (99.66%). Additionally, Lactobacillus, Zymomonas and Saccharomyces were the detected core microbiome for the collected Tej samples. Both bacterial and fungal communities had shown no statistically significant differences in alpha diversity analysis based on the area of sample collection. However, the bacterial communities had a statically significant difference in Unweighted Unifrac beta diversity analysis. Generally, the observed shared physicochemical characteristic features and the dominance by certain group of microorganisms might be seen as a boon for the development of direct fermentation system to this traditional alcoholic beverage.

Cereal- and Fruit-Based Ethiopian Traditional Fermented Alcoholic Beverages.

Traditional fermented alcoholic beverages are drinks produced locally using indigenous knowledge, and consumed near the vicinity of production. In Ethiopia, preparation and consumption of cereal- and fruit-based traditional fermented alcoholic beverages is very common. Tella, Borde, Shamita, Korefe, Cheka, Tej, Ogol, Booka, and Keribo are among the popular alcoholic beverages in the country. These beverages have equal market share with commercially produced alcoholic beverages. Fermentation of Ethiopian alcoholic beverages is spontaneous, natural and uncontrolled. Consequently, achieving consistent quality in the final product is the major challenge. Yeasts and lactic acid bacteria are the predominate microorganisms encountered during the fermentation of these traditional alcoholic beverages. In this paper, we undertake a review in order to elucidate the physicochemical properties, indigenous processing methods, nutritional values, functional properties, fermenting microorganisms and fermentation microbial dynamics of Ethiopian traditional alcoholic beverages. Further research will be needed in order to move these traditional beverages into large-scale production.