Monitoring real-time enzymatic hydrolysis of Distillers Dried Grains with Solubles (DDGS) by dielectric spectroscopy following hydrothermal pre-treatment by steam explosion.

Dielectric spectroscopy (DS) has been used to monitor the simultaneous saccharification and fermentation of lignocellulosic biomass by measuring its dielectric state. However, it is unknown whether following steam explosion (SE) pre-treatment, lignocellulose would still maintain a dielectric state, and, if maintained, whether the dissipation during enzymatic hydrolysis could be monitored. Distillers Dried Grains with Solubles (DDGS), pre-treated by SE, was found to have a capacitance (C = 580 kHz) of approximately 24 pF cm(-1). Following addition of full-strength cellulolytic cocktail A (CC-A; R-2 = 0.97) and 1/3 strength cocktail B (CC-B; R-2 = 0.96), a natural logarithmic decay in capacitance was determined. Furthermore, the DS biomass probes quantified the initial linear rate of dissipation in capacitance during hydrolysis. The rate of CC-B was 34% that of CC-A. These data extend scope and utility of DS biomass probes for monitoring the enzymatic hydrolysis of SE-pre-treated lignocellulosic substrates in real-time. (C) 2012 Elsevier Ltd. All rights reserved.