Solid state fermentation of finger millets: Experimental investigation and modeling of pressure drop and gas holdup of finger millets bed

Abstract

The solid state fermentation was carried out on the finger millet bed using Aspergillus oryzea (MTCC 3107) at various bed thicknesses of 0.075, 0.15 and 0.225 m. The air was continuously supplied to the finger millet bed at three velocities of 0.12, 0.24 and 0.36 m/s. The pressure drop and gas holdup of finger millet bed were measured during solid state fermentation. Both the pressure drop and gas holdup was found rising up to 60 h of fermentation and thereafter started declining as increase in the air velocity and bed thickness. A correlation models were developed to predict the pressure drop and gas holdup of the finger millet bed during fermentation using dimensional analysis. The developed models were effective in predicting the parameters within the experimental domain (higher R2 (>0.97) and lower SE values (