Size reduction methods (e.g., ball milling and disk
refining) decrystallize cellulose and reduce crystallinity, but they
also reduce the particle size of cellulosic biomass (Yoshida et al.,
2008; Zhang et al., 2007). Since decreasing crystallinity and reducing
particle size happen simultaneously, their effects on sugar yield
of hydrolysis substrates are confounded. It is difficult to determine
the increase in sugar yield of the substrates produced by size
reduction is primarily attributed to having a low crystallinity or a
small particle size.