Heat delivered with pressure makes the wetted substrate vulnerable to further breakdown, enabling a good saccharification process. The efficiency of HP pre-treatment was also proved in the studies of Arumugam and Manikandan (2011) and of Gabhane et al. (2011), where use of an autoclave was the most effective method for increased sugar yield. Moreover, Singh and Trivedi (2013) reported that autoclave treatment (at 121C for 30 min) coupled with acidification is an effective and cheap method, although it was observed that acid caused the formation of inhibitors.