In this work the introduction of a cellulase treatment prior to NCC isolation was assessed. NCC was produced
using sulfuric acid at two different concentrations (62 and 64% wt.). The effect of pore size for filtration
step was also assessed. The smaller acid dose leaded to yields up to 65–70% and average size up to
160 nm. It also produced crystals with reduced sulfur content (0.6–1%). Cellulase pretreatment influenced
NCC characteristics, as it increased overall yield a 12%, increased average particle size around
35 nm and reduced NCC sulfur content up to a 0.8%. We found that different conditions of enzymatic
treatments led to quantitative differences on their effects on NCC. Acetate buffer used for enzymatic
treatments was found to counteract effects of acid. The evidence presented in this work suggested that
pretreating fibers with this cellulase represents a very interesting option to partially replace chemicals
on NCC isolation.