Fermentable Sugar Production from the Peels of Two Durian ( Durio zibethinus Murr.) Cultivars by Phosphoric Acid Pretreatment

摘要

The potential of durian ( Durio zibethinus Murr.) peel as feedstock for the production of fermentable sugars was evaluated. Durian peel biomass from two cultivars, monthong ( Durio zibethinus Murr. cv. Monthong) and chanee ( Durio zibethinus Murr. cv. Chanee), were pretreated with different concentrations (70%, 75%, 80%, and 85%) of phosphoric acid (H 3 PO 4 ) at a moderate temperature of 60 °C for 60 min. The H 3 PO 4 -pretreated durian peel biomass was then subjected to enzymatic hydrolysis. Significantly higher glucan (44.74 ± 0.21%) content was observed in the monthong peel compared to the chanee peel (42.06 ± 0.28%). Phosphoric acid pretreatment caused the significant solubilization of the xylan and acid soluble lignin (ASL) contents. This enhanced the enzymatic hydrolysis process causing a significant increase in the hydrolysis efficiency and glucose concentration. The highest hydrolysis efficiency and glucose concentration were obtained after 72 h from the 75% H 3 PO 4 -pretreated peel biomass for both the monthong (90.33 ± 0.42% and 9.55 ± 0.11 g/L, respectively) and chanee (90.06 ± 0.40% and 8.56 ± 0.13 g/L, respectively) peels. Biomass to glucose recovery for monthong and chanee were improved by approximately 7- and 6-fold, respectively. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis showed destruction of the peel biomass structure and changes in the cellulose crystallinity index ( CrIs ).