Microbial and chemical processes associated with burukutu, a Ghanaian fermented alcoholic beverage

Abstract

To identify and enumerate the different microorganisms involved in the fermentation of Burukutu, a traditional fermented sorghum beverage and the chemical changes associated with the fermentation. Information on the different methods used in its production were also assessed and documented amongst the processes through a questionnaire survey and personal interviews. At each stage of the production process, microorganisms involved were enumerated, isolated and identified and also the chemical changes associated with the process. The keeping quality of Burutuku was also studied. Results showed that there were no differences in the processing procedures amongst the Burukutu producers within the Greater Accra region. Types of microorganisms involved in the fermentation were predominantly lactic acid bacteria; Lactobacillus fermentum, L. plantarum, L. acidophilus, Lactococcus lactis subsp.lactis and Lactobacillus brevis, which were mainly associated with the acidification process and the yeasts; Saccharomyces cerevisiae and Candida krusei that brought about the alcoholic fermentation. Of the LAB isolates, Lactobacillus fermentum, L. plantarum and Lactococcus lactis subsp.lactis showed amylolytic properties. LAB isolates had antimicrobial activities against Staphylococcus aureus, Escherichia coli and Salmonella typhimurium. During the fermentation, Burukutu microbial numbers (log10 CFU/ml) varied between 6.66 to 8.14 for lactic acid bacteria and 6.82 to 8.18 for yeast. Similarly, pH, titratable acid, soluble solids and alcohol level of Burukutu during the fermentation varied between 3.36 to 2.88, 0.54 to 0.82; 7.5 to 3.33 and 0.99 to 4.47, respectively. Burutuku keeps best for up to twelve weeks if glass bottled, pasteurized and stored in a climatic chamber. This being the first major study of Burukutu in Ghana, it could be used to improve and upgrade the traditional production process