To achieve enzymatic degradation in the production of ethanol
by enzymatic hydrolysis, a pretreatment process is necessary. For
the concentrated phosphoric acid pretreatment process, one gram
of dry lignocellulosic feedstock was placed in a 50 mL plastic centrifuge
tube, and then mixed with 10 mL of pre-calibrated concentrated
phosphoric acid (e.g., 83.0–85.9%) using a glass rod.