Influence of Different Processing Methods on Aflatoxin Level in <i>Ogi</i> Slurry Produced from Millet (<i>Pennisetum typhoideum</i>)

Abstract

The global shortage of cereal foods arising from improper processing and preservation methods adopted in some of our industries could be the sources of contamination of various food products which could lead to devastating health disorder. From this study, millet grains were subjected to different processing methods such as fermentation, alkaline boiling, oven drying and sun drying. The microorganisms associated with the processed samples were isolated and identified using standard microbiological and biochemical methods. The extraction, detection and quantification of aflatoxin from ogi slurry were quantified using thin layer chromatography. The sample fermented with ethanol and water showed higher fungal count 37.33cfu/ml while the sample fermented in sodium hypochloride shown no growth of Aspergillus flavus with fermentation time at initial inoculation. The milled fermented oven dry sample showed higher colony counts 14.50 cfu/g when compared to milled sun-dry and alkaline boiling fermented samples. The aflatoxin level of the ogi slurry ranged from 0.00ppb to 0.02ppb. Samples fermented with water and ethanol showed high effect in removal of aflatoxin B and G produced by toxigenic Aspergillus flavus while the alkaline boiling showed less effect on aflatoxin B1 and B2. Aflatoxin G1 and G2 were completely removed/destroyed from the sample fermented with ordinary water with aflatoxin level 0.00ppb. The sample subjected to oven dry and sun-dry showed complete removal/reduction in aflatoxin B1 and G1. The reduction in aflatoxin level of ogi slurry produced from millet using different processing methods showed its permissible level below the standard as recommended by National Agency for Food Drug Administration and Control (NAFDAC) and European Union which could be promising prior to this methods in controlling the level of contaminant in our food products for human use.