Optimizing Xylose Yield from Coffee Cherry Processing Waste (CCPW) via PEG-Assisted Enzymatic Hydrolysis
DOI:
https://doi.org/10.25047/tefa.v3i3.7146Abstract
Coffee cherry processing waste is a lignocellulosic residue with considerable potential as a renewable feedstock for sugar production. This study investigated the effect of depectination and polyethylene glycol (PEG) 6000 supplementation on enzymatic sugar release from Robusta CCPW. CCPW was depectinated and subsequently pretreated with 3% NaOH at 80°C for 2.5 h to reduce lignin and pectin contents and improve hemicellulose accessibility. Enzymatic hydrolysis was performed using xylanase with PEG 6000 concentrations of 3, 5, 7, and 9 g/L under fed-batch conditions for 96 h at 40°C. We determined xylose- and glucose-equivalent reducing sugar concentrations using the DNS method with separate calibration curves and spectrophotometric measurements at 550 and 540 nm, respectively. Depectination reduced pectin content from 11.5% to approximately 1.4%; PEG 6000 supplementation significantly increased sugar release compared with the 0g/L control. The highest xylose-equivalent concentration and yield were obtained at 9 g/L, reaching 1.96 g/L and 78.76%, respectively, compared with 0.602 g/L and 24.18% in the control. The highest glucose-equivalent concentration and yield were obtained at 7 g/L PEGG 6000, reaching 2.77 g/L and 71.02%, respectively. The enhanced hydrolysis observed in PEG-Supplemented treatment may be associated with improved enzyme accessibility and reduced non-productive enzyme adsorption onto lignin, as proposed in previous studies. Unlike the authors' previous work focusing on downstream crystalline xylose production from CCPW, the present study specifically evaluates depectination and PEG 6000 supplementation as strategies to enhance enzymatic sugar release prior to purification and crystalization.
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Copyright (c) 2026 Silvia Oktavia Nur Yudiastuti, Wiwik Handayani, Aulia Brilliantina, Elok Kurnia Novita Sari, Rizza Wijaya, Ahmad Haris Hasanuddin Slamet, Remita Anggraini Permatasari
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