Response of chemical profile and enzymatic digestibility to size reduction of woody biomass

•Redistribution of chemical compositions occurs during the process of size classification.•Glucan conversion is affected synthetically by the augment of surface area, lignin enrichment, and cellulose decrystallization that accompany with the process of size reduction.•Diversity of woody recalcitrance in bioconversion is reflected by the distinguishing responses of enzymatic digestibility to size reduction.

Size reduction is a prerequisite step for enzymatic saccharification of woody biomass. The existing controversies on its effectiveness reflect the complexity thereof. The present study focused on the dependence of enzymatic digestibility on substrate size among wood species. The results showed that the size reduction not only resulted in the augment of surface area, but also lignin enrichment and cellulose decrystallization. However, the changes in surface area, chemical profile, and crystallinity were different among wood species, which confirmed the diversity of woody biomass in bioconversion, and could be used to interpret the various responses of glucan conversion to size reduction.