Comprehensive Evaluation of Physicochemical Properties and Microbial Dynamics of Cheka: Traditional Fermented Beverage in Southern Ethiopia.

Cheka is a grain- and vegetable-based traditionally fermented beverage usually consumed in southwest Ethiopia, mainly in Konso and Derashe. Conventionally, it is made by spontaneous fermentation and therefore mostly relies on the actions of autochthonous microorganisms. Due to the lack of scientifically documented information on the microbiology of the Cheka fermentation process, we undertook this study to explore the microbial profiles and physicochemical properties involved in Cheka fermentation. Cheka is traditionally prepared in the laboratory using aseptic procedures with locally sourced ingredients from Arba Minch. The physicochemical properties and dominant and spoilage organisms at various stages of fermentation and in the final products were analyzed. The pH reduced from 4.10 to 2.88, while the titratable acidity changed from 0.06% to 1.60% lactic acid during 0 to 48 h of fermentation. Protein content increased from 1.57 ± 0.04 to 3.62 ± 0.09 and from 1.67 ± 0.08 to 3.91 ± 0.06 at 0 h and 48 h for Cheka and Madhota. A significant increase in carbohydrate content was observed in Cheka and Madhota from 21.14 ± 1.95 to 51.51 ± 3.00 g/100 g and from 12.11 ± 1.95 to 51.58 ± 2.95 g/100 g, respectively. The analysis of microbial counts in Cheka showed that the total viable count (TVC) increased from 8.72 to 9.4 log during 0-48 h of fermentation. Yeast and mold counts increased from 6.71 to 8.80 log (CFU/mL). Clostridium was removed within 48 h of fermentation, and Enterobacteriaceae showed a significant (p < 0.05) reduction from 4.90 to 1.77 ± 0.20 and from 4.60 ± 0.30 to 1.34 log (CFU/mL) in both Cheka and Madhota products. The alcohol content of Cheka increased from 3.00% to 16.00% (v/v) between 0 and 48 h of fermentation. The findings of this study provide a comprehensive understanding of the relationship between physicochemical parameters and the microbial characteristics of Cheka during fermentation. This understanding will aid in ensuring the safe production and enhancing the quality of Cheka and similar products in the future.