Assessment of microbiological changes during production of malted and fermented finger millet flour

Abstract

Finger millet is widely consumed as porridge though not commercially grown in Rwanda. Traditional techniques of malting and fermentation are found to enhance bioavailability of nutrients. Hence the study aimed to assess microbiological changes among non-malted, malted and malted and fermented flour. Grains were purchased from local market and subjected to malting and milled. A portion of the malted milled flour was subjected to fermentation by mixing with water in the ratio of 2:1; and then allowed to auto ferment at 30°C for 48 hours. The fermented dough was mechanically dried and then milled into flour. All three samples of flours were microbiologically studied using Total Plate Count (TPC), Lactic Acid Bacteria (LAB), yeasts and moulds count. Data were analyzed using Microsoft Office Excel and results were presented as Logarithm of colony forming unit per gram (log cfu/g). Analysis showed that LAB greatly increased from 4.66 log cfu/g, 6 log Cfu/g to 6.24 log cfu/g while TPC greatly decreased from 5.69 log cfu/g, 5 log cfu/g and to 4.84 log cfu/g in non-malted, malted and malted and fermented flour respectively. Yeasts count also varied from non-malted, malted flour and to malted and fermented flour with results of 3.3 log cfu/g, 4.66 log cfu/g and 3.9 log cfu/g respectively. Moulds were absent in non-malted and malted flour while they were found to be low in malted and fermented finger millet flour.

Keywords: Finger millet, Lactic Acid Bacteria (LAB), yeasts, moulds, malting, fermentation