18In this work the introduction of a cellulase treatment prior to NCC isolation was 19 assessed. NCC was produced using sulfuric acid at two different concentrations (62 and 20 64% wt.). The effect of pore size for filtration step was also assessed. The smaller acid 21 dose leaded to yields up to 65-70% and average size up to 160 nm. It also produced

21NCC preparation using sulfuric acid hydrolysis from cellulase pretreated fibers was optimized in 22 order to obtain the highest possible yield with 62% and 65% wt. sulfuric acid throughout two 23 statistical plans. At optimal conditions (10U/g odp cellulase, 25 min hydrolysis, 47 ºC and 62 % 24 wt. H 2 SO 4 ) high yields were obtained (≥80%) including an increase produced by enzyme of ~9 %. 25Optimal conditions produced nanosized particles of around ~200 nm with a reduced surface 26 charge and sulfur content. The performed optimization allowed reducing the hydrolysis time in a 27 44%, and also increasing yield in more than 10% compared to results exposed in previous works.

In this work, conditions for an enzymatic pretreatment prior to NCC isolation from cotton linter were assessed. Different cellulase doses and reaction times were studied within an experimental design and NCC were obtained. At optimal enzymatic conditions (20U, 2 h), a total yield greater than 80% was achieved and the necessary enzymatic treatment time was reduced 90%. Different intensities of enzymatic treatments led to proportional decreases in fiber length and viscosity and also were inversely proportional to the amount of released oligosaccharides. These differences within fibers lead to quantitative differences in NCC: increase in acid hydrolysis yield, reduction of NCC surface charge and crystallinity increase. Benefits produced by enzymatic treatments did not have influence over other NCC characteristics such as their sulfur content (≈1%), size (≈200 nm), zeta potential (≈-50 mV) or degree of polymerization (≈200). Evidence presented in this work would reduce the use of harsh sulfuric acid generating a cleaner stream of profitable oligosaccharides.

18In this work, treatments with a xylanase (X) and carbohydrases mixture (Cx) were 19 applied on a TCF bleached sisal pulp in order to obtain high-cellulose content fibers 20 applicable on a wide range of uses. A limit of ≈12% w/w final content in hemicelluloses 21 was found regardless of the enzymatic treatment assessed. An extraction with 4% and 22 9% w/v NaOH was performed for further hemicelluloses removal. We found that NaOH