Abstract

Brewing and consumption of traditional beers have socio-economic importance in most African countries, including Rwanda. In this study, the microbiological quality (of selected microbes) of commercially produced traditional banana beer was investigated, using both traditional culture-dependent and culture-independent methods. Two brands of commercially produced traditional banana beer (brands A and B) were obtained from a local market in Kigali, Rwanda. Brands A and B recorded the total viable counts (TVC) were 5 and 124 cfu.ml^-1 respectively, whereas the mean count for lactic acid bacteria were found to be 30 and 80 cfu.ml^-1. Yeasts and moulds were 17 cfu.ml^-1 in brand A, and none detected in brand B Coliforms, Salmonella spp, and Staphylococcus spp were not detected in either brand of traditional banana beer, through the culture-dependent and culture-independent techniques. Denaturing gradient gel electrophoresis (DGGE) analysis of the 16S rRNA genes detected the presence of Lactobacillus farraginis,Lactobacillus diolivorans and Lactobacillus hilgardii as dominant organisms only in brand A. The absence of pathogenic micro-organisms suggests proper hygiene and sanitation, during processing and after production of the banana beer.

Key words: Traditional banana beer ‘urwagwa’, Rwanda, Lactobacillus, microbial quality, denaturing gradient gel electrophoresis (DGGE), food safety.