High pressure processing (HPP) is an emerging technology of food preservation which has not been used as pretreatment of lignocellulosic material such as sugarcane bagasse (SCB). In this work the effect of high pressure processing combined with sodium hydroxide (NaOH) was evaluated on the enzymatic hydrolysis of three different types of sugar cane bagasse: milled bagasse (MB), whole bagasse (WB) and previously hydrolized bagasse (PHB). A 25 g sample of each biomass were suspended in NaOH solutions (0, 3, 6 and 10% w/v) by keeping a liquid:solid ratioequal to 6:1 and placed inside bags sealed to vacuum. Samples were then submitted to 350, 400 and 450 MPa at 50�C during 10 min. Results showed that lignocellulosic fractions obtained from all baggases and treated under the three pressure levels were similar; however the cellulose fraction decreased with increments on the applied pressure. Regarding the hemicellulose fraction, this was more susceptible to NaOH concentration than pressure and pre-hydrolysis removed up to 70%, while lignin was more drastically removed in WB at 450 MPa and 3% NaOH. Otherwise, the complete and compact structure of the raw bagasse suffered microscopic alterations (i.e. cracks, tiny holes and fragments flaked off from the surface) after undergoing the pretreatment with HPP and NaOH, which were clearly observed at the highest pressure tested (450 MPa). A maximum glucose yield of 48.22g/L was obtained after treating baggase delignified with 3% NaOH at 72 h and submitted to enzymatic hydrolysis under optimized conditions, i.e. celluclast 1.5 (42.7 EGU/gbagazo-1) plus novozyme 188 (22.71 CBU/gbagazo), 240 rpm, and 50 �C. This hydrolysate might be a suitable substrate to produce bioethanol using sugarcane bagasse.

Effect of combining high pressure processing with sodium hydroxide on sugarcane bagasse as a new alternative pretreatment for ethanol production

247th National Meeting (2014)

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