Effect of Different Fermentation Times on the Nutritional Value and Microbial Load of Cassava (Manihot esculenta) Flour

Abstract

Fermentation is used as a process to reduce the level of hydrogen cyanide from cassava roots. This study aimed at evaluating the effect of different fermentation times on the nutritional value of cassava flour, Manihot esculenta. Cassava tubers were bought from Bokkos Main Market, processed at the National Veterinary Research Institute Vom, into flour using standard methods, and analyzed for microbial load, nutrient composition and hydrogen cyanide level at different fermentation times (0hours, 24 hours, 48 hours, and 72 hours). The results showed that fermentation time significantly reduced the hydrogen cyanide levels from 0.024mgHCN/10g at 0hours of fermentation to about 0.004mgHCN/10g by 72hours and that increased fermentation time impacted microbial succession with decreased pH from 7.4 to about 4.3 with bacterial and fungal counts peaking at 48 hours and decreasing by 72 hours. Nutritional analysis demonstrated improved nutrient profiles with prolonged fermentation, indicated by an increase in crude protein, crude fibre, and lipids with reductions in anti-nutritional factors which enhanced safety of the final product. Optimal fermentation was identified at 72 hours for balancing nutritional value with microbial safety and establishing that increased fermentation time significantly improved the nutrients profile of the fermented cassava flour.