Evaluation of Microbial and Nutritional Quality of Fermented Dried Roasted Thick Porridge (Mkarango)

Abstract

Most of the products of maize flour fermentation in Kenya undergo wild fermentation in a natural process. One of these is locally roasted maize flour commonly known by its local name Mkarango which is popular in the Western region of Kenya where it is used in different ways. Mkarango is mostly made through wild fermentation which is known to pose health risks as it is unhygienic and time-consuming, with the quality of the resultant product being inconsistent. The aim of this study was to evaluate the population of lactic acid bacteria, and sensory characteristics of dried roasted thick porridge (mkarango). Six different mkarango products made with addition of Lactobacillus plantarum and Lactobacillus brevis in different ratios were studied for microbial quality, mineral element content and sensory characteristics. Titratable acidity and pH properties of the products were also determined. These were done following recommended standards. After 24 hours of fermentation, products with Yeast+ L. plantarum+ L. brevis (1:2) and Milk+ L. plantarum+ L. brevis (1:2) had the highest pH values (5.12) while products with Milk+ L. plantarum+ L. brevis (2:1) had the lowest pH values (4.8). Yeast, molds, and Lactic Acid Bacteria had the highest in all the samples tested while Enterobacteriaceae the least. The overall acceptability of the product of the product prepared from Milk + L. plantarum + L. brevis (2:1) had the final score of 4.7 on the 5-point hedonic scale. The results of the trace elements zinc and iron ranged from 2.7 mg/100 g to 3.9 mg/100 g and 2.7 mg/100 g to 16.9 mg/100 g on the product respectively. Fermentation creates an environment that is conducive for the population of lactic acid bacteria. This results in increased volume of lactic acid that is responsible for improved nutritional quality of Mkarango.