Effect of Inoculum Size on Solid State Fermentation of Cassava (Manito esculenta Crantz)

The food value of cassava is limited because of the presence of cyanogenic glucosides (linamarin and lotaustralin), which when hydrolyzed by the endogenous enzyme linamarase, produce acetone cyanohydrin and hydrogen cyanide. This research is aimed to evaluate how inoculum size affects the solid-state fermentation of cassava by the fungus R. Oligosporus. The enzymatic activities and biochemical parameters were measured using spectrophotometer and the colorimetric approach. The supernatant of the R. Oligosporus was used as the crude extract or sample for the various assays that includes test for total amylase activity, glucose and total soluble proteins. The results for Amylase activity show that after 72 h, amylase activity increased significantly (p < 0.05) in the unfermented control (0%) at 20% inoculum size. Meanwhile, at different inoculum sizes, there was also a rise in amylase activity. Furthermore, the glucose analysis revealed that after 72 h of fermentation, the glucose concentration, which was low in the control, had considerably increased (P < 0.05). In addition, an increase in soluble proteins was also observed at all inoculum size fermented and both the unfermented control. The findings of the current research showed that solid state fermentation of cassava with the fungus R. Oligosporus increased nutritional value (proteins and glucose) and nutrient bioavailability at all inoculum sizes studied.