A Comparative Study on Microbiological and Physico-chemical Properties of Three Local Alcoholic Beverages Produced and Consumed in Mombasa County, Kenya
E. W. Mwakio
Department of Pure and Applied Science, Faculty of Applied and Health Sciences, Technical University of Mombasa (TUM), P.O.Box 90420-80100, Mombasa, Kenya.
M. L. Chimbevo *
School of Health Sciences, Kirinyaga University, P.O.Box 143-10300, Kerugoya, Kenya.
J. B. Malala
Directorate of Research, Grants and Endowments, Mt Kenya University, P.O.Box 342-001000, Thika, Kenya.
H. Makonde
Department of Pure and Applied Science, Faculty of Applied and Health Sciences, Technical University of Mombasa (TUM), P.O.Box 90420-80100, Mombasa, Kenya.
J. M. Kahindo
Department of Pure and Applied Science, Faculty of Applied and Health Sciences, Technical University of Mombasa (TUM), P.O.Box 90420-80100, Mombasa, Kenya.
M. M. Awadh
Department of Pure and Applied Science, Faculty of Applied and Health Sciences, Technical University of Mombasa (TUM), P.O.Box 90420-80100, Mombasa, Kenya.
J. B. Msanzu
Department of Pure and Applied Science, Faculty of Applied and Health Sciences, Technical University of Mombasa (TUM), P.O.Box 90420-80100, Mombasa, Kenya.
*Author to whom correspondence should be addressed.
Abstract
Physico-chemical properties and micobial contamination of three local brews (Mnazi, Mchuchula and M’bangara) consumed in Mombasa County were assessed. The bacteria concentration enumeration was determined by incubation of each sample for two days at 35°C to 37°C on plates containing colony forming units (CFUs) on Aerobic plate count (APC) agar and Lactic acid bacteria (LAB) on Rogosa agar plates. Growth on plates were positive for heterotrophic and LAB bacteria with high levels recorded in 10-2 aliquots of each sample. M’bagara recorded higher levels of LAB (201.0±24.79), with Mnazi and Mchuchula having slightly low levels of LAB of 182.0±26.96 and 129.0±5.20 respectively despite some of the plates not being used for enumeration since they had above 250 CFUs. Yeast detection and enumeration was also determined. Low numbers of yeast cells were recorded in M’bangara (30.0±5.72), with Mchuchula recording the highest number of yeast cells (66.30±3.07). Physico-chemical properties determined included colour, acidity, pH and alcohol in terms of volume i.e Alcohol by Volume (ABV). M’bangara recorded the highest titratable acidity (0.9±0.04), and lowest pH (2.7±0.07) whereas the highest ABV levels were recorded in M’bangara (4.6±0.12). Confirmatory results for total coliforms, feacal coliforms and E. coli indicate the absence of contamination from sewage material. There were significant variation (p>0.05) in terms of physico-chemical properties and microbial contamination in the three analyzed local brews. In this study, local brews consumed in Mombasa County contain non-miocrobial and microbial contaminants which may be related to effects of consumption of these brews.
Keywords: Local brews, physico-chemical properties, microbial contaminants.