Microbiology of Bukuri and Cabbage-Shameta fermentation in ,East Wollega zone, Oromia region, Ethiopia

Abstract

Bukuri is a cereal based traditional fermented beverage prepared from locally available cereals (maize, barely, sorghum, millet, wheat, teff and malt flours: likewise, cabbage shameta is made from maize, barely and cabbage seeds (Brassica abissinicum) using traditional equipments in Nunu town, East Wollega zone. The objective of this study was to evaluate the microbiology of Bukuri and Cabbage-shameta fermentation. Seventy samples, comprising 35 each of Bukuri and cabbage-shameta, were collected from study area. Data related to the product description, raw materials and preparation techniques were collected using closed and open ended questionnaires. Samples were examined microbiologically for total aerobic mesophilic bacterial counts, lactic acid bacteria, Enterobacteriaceae, yeasts and moulds. Titratable acidity and pH of samples were also analyzed. Simple descriptive statistics and SPSS statistical soft ware (version 16) were employed for data analysis.The results revealed that Bukuri samples had total mean count of 6.84 , 6.69 , 6.72 and < 1 Log CFU/ml for Aerobic mesophilic bacteria, Lactic acid bacteria, Yeasts, Enterobacteriaceae and moulds respectively. The samples had a mean pH of 3.93 and TA of 3.23%. Similarly, cabbage-shameta samples had a total mean count of 6.66 , 6.67 , 0.53 , 5.74 and 0.75 Log CFU/ml for Aerobic mesophilic bacteria, Lactic acid bacteria,, Enterobacteriaceae, Yeasts and Moulds respectively and mean pH of 3.96 and Titratable acidity of 7.42%. But during laboratory Bukuri fermentation from 0 hr to 72 hrs and cabbage-shameta from initial day to 14 days fermentation, the result had shown that Aerobic mesophilic bacteria generally reduced, Lactic acid bacteria and Yeasts increased, Enterobacteriaceae and moulds appeared initially and reduced to undetectable level then after throughout fermentation in both samples. Moreover, the pH was reduced from 4.2 to 3.98, 5.21 to 3.92 and TA was increased from 2.5 to 4.3%, 3.9 to 8.02% during laboratory bukuri and cabbage shameta fermentation respectively.By the end of 7 days of bukuri fermentation and 20 days of cabbage shameta fermentation, the pH was dropped to 3.52 and 3.79, respectively, the time when both products became too sour and unfit for consumption due too over acidification by LAB. It could be concluded that both Bukuri and cabbage –shameta are low -alcoholic, acidic products of relatively short shelf-life.