Different response between woody core and bark of goat willow (Salix caprea L.) to concentrated phosphoric acid pretreatment followed by enzymatic saccharification

Parts of extractives and carbohydrates were removed by concentrated phosphoric acid pretreatment, and this trend was more obvious in bark than woody core. In bark, 60% of xylan and 30% of cellulose was removed by acid pretreatment but only 40% of xylan and 8.3% of cellulose in woody core. Removal of polysaccharides in cell wall and destruction of crystal structure (cellulose crystallinity reduction) in cellulose caused the more enzymatic saccharification by commercial cellulases cocktails. Bark showed three times higher cellulose to glucose conversion by cellulases but woody core was two times higher than those of untreated.