Biochemical and microbiological analyses of Burukutu (native beer) and a brand of factory-based lager beer (STAR)

Consumption of Burukutu (native beer) among the people of the area of study is a norm. The techniques applied in its production are crude and non scientific. As a result, undesirable compounds, which may themselves be toxic, could be produced as components of the ‘brew’. Also, microbes present may be pathogenic. Ten samples were aseptically collected. A composite of 2 ml portions of each of nine (9) Burukutu samples was prepared for microbial count and identification. In the case of organic metabolites and alcohol content, individual samples were analysed. Spectrophotometry was applied to determine the alcohol content; mass spectrometry method was used to identify the metabolites generated. Nutrient agar and indole test were applied for aerobic plate count and microbial identification. The results obtained revealed three isolates in all the samples thus: Escherichia coli, Bacillus species and Saccharomyces cerevisiae. The alcohol content ranged between 2.0-2.6% (v/v). Metabolites generated in both Burukutu and factory-based lager beer included glycerine, 1-pentanol, methanol, 1-glyceraldehyde, trimethylene oxide, 1-butanol, toluene, benzene acetic acid Propanoic acid, 2-hydroxy ethyl ester, Heptafluorobutyric acid, n-Pentyl ester, 4-butoxy-5,7-dinitrobenzo[1,2,5] Thiadiazole, Benzene acetic acid, 2 butyl ester, ethyl alcohol. Both Burukutu contain undesirable metabolites which may synergise with alcohol making it toxic to the system. Personal and environmental hygiene will help reduce levels of contaminants in alcoholic beverages otherwise pathogenic microbes could grow in the liquor being consumed.