Untreated elephant grass exhibited a protein content of 5.55% but, after pretreatment, unwashed substrates had higher protein contents than water-washed samples. The highest protein content (8.74%) was derived from pretreatment at 200 C for 6 min (unwashed sample), whereas the lowest (1.63%) was produced at
190 C for 8 min (water-washed sample). The presence of higher protein contents in substrates produced at higher pretreatment temperatures is probably due to protein denaturation, which causes their precipitation and/or adsorption onto the lignocellulosic fibers (Jaenicke, 1991).