Derived insoluble matter distribution
Cellulose, hemicelluloses and lignin are the major 
polymers in the plant cell walls, and any change in or 
removal of these components would be expected to 
consequently affect enzymatic digestibility. However, 
experimental results have been rather inconsistent. 
Grohmann et al. and others showed direct relationships 
between hemicellulose removal and glucose yields from 
cellulose [111,145–150], but other reports do not support 
a role for hemicellulose removal in changing cellulose 
digestibility [151–154]. Similarly, conflicting conclu-
sions have been reached on the importance of lignin 
removal in enhancing cellulose conversion [102,155–157]. 
All plant cell wall constituents are modified to different 
extents by pretreatments, depending on the technolo-
gies and conditions applied, making it challenging to 
deduce whether altering cellulose microfibrils, removing 
hemicelluloses, modifying or relocating lignin, or other 
effects on the substrate are responsible for improving 
enzyme effectiveness.