The fermentability of lignocellulose hydrolyzates have been predicted from
the responses of a combination of chemical gas sensors. The hydrolyzates we
re prepared by dilute-acid hydrolysis of wood from pine, aspen, birch, and
spruce. The volatile emission from the hydrolyzates before fermentation was
measured, and the sensor array response pattern was compared with the obse
rved fermentability of the hydrolyzates, i.e. with the final ethanol concen
tration after fermentation and the maximum specific ethanol production rate
. Two concentration parameters in the hydrolyzates, furfural and the sum of
furfural and 5-(hydroxymethyl)furfural (HMF), were also predicted from the
responses. The sensors used were metal oxide semiconductor field effect tr
ansistors (MOSFET), tin oxide semiconductor devices, and conductive polymer
sensors configured in two sensor arrays. The sensor array response pattern
was analyzed by principal component analysis and artificial neural network
s. Predictions from artificial neural networks deviated from measured value
s with less than 15%.