Effect of Fermentation on Aflatoxin Content of Ogi Produced from MouldyMaize ( Zea mays )

Abstract

Mycotoxins are toxins produced naturally by fungi. They are carcinogenic and can affect food quality and safety. Effect of fermentation on aflatoxin content of ogi produced from moldy maize was investigated in this study. Moldy and non-moldy maize grains were fermented and proximate, microbial and aflatoxin content analyses were carried on the samples for 72 hr fermentation periods at 24 hr intervals. Ogi was produced using the standard method of production and dried to give Ogi flour. Results of the proximate analysis show decrease in protein, crude fiber, ash and carbohydrate contents during the fermentation periods. The fat content of steeped non-moldy maize increased (4.32%-4.36%) compared to that of moldy maize (3.94%-4.01%), but they are not significantly different. Microbial analysis showed a reduction in yeast and mold counts, with values ranging from 7.0-0.50 CFU /g × 104 in non-moldy maize and 11.45-2.45 CFU/g × 104 for moldy maize at the end of 72 hr fermentation. Increased values of Lactic acid bacteria counts were observed at 48hr fermentation for both samples. During fermentation, aflatoxin contents in the moldy grains reduced from initial concentration of 58.00 μg/kg in the raw maize sample to 3.13 μg/kg at 72 hr fermentation period. This study has shown that aflatoxins content in moldy maize can be reduced by natural fermentation processes.