Studies on the microbiology of "nmada" a malted maize beverage

Abstract

The main ingredionts used in the production of "Nmada" were examined to test their microbiological. quality and to determine the source of microbial load in the finished produot. The moulds found on the raw and malted maize grains were Penicillium spp,, Aspergillus spp. and Rhizopus spp. Bacterial types isolated include Bacillus spp., a few Gram-positive cocci and Gram-negative rods. Six out of the total number of 10 maize malt samples had total bacterial counts over 100,000 per g. The remaining 4 sanples had counts under 50,000 per g. Total bacterial counts for sugar samples ranged from 12 to 46 per 10g. Salt samples h~d counts of ~,200 to 2,300 per 10g. Two samples of malt flour prepared in the laboratory showed a better microbiological quality as compared to the sample from the two producers. Total bacterial counts wore 510 per g and 720 per g respectively. Yeast and moulds counts were of tho order 1,260 per g and 1,460 per. g. Analysis of fresh samples of 'Nmada' made from maize malt prepared in the laboratory gave no counts for both bacteria and yeasts and moulds. The fresh sampIes of 'Nmada' from the two producers had total baoterial counts ranging from 80 to 860 per ml and yeast and moulds counts of 5 to 780 per millilitre. Five major groups of organisms which were identified as Bacillus spp. were found to dominate the microflora of the spoilt beverage. It was also observed that using a malt with 1ow microbial load resulted in a beverage of better microbiological quality