Chemical-free extraction and identification of sugar components from oil palm biomass through a hydrothermal process

Abstract

Purpose: The aims of this research were to extract sugar-based products from oil palm biomass, oil palm fronds (OPFs) and oil palm fruit pressed fibers (FPFs) via a hydrothermal process using accelerated solvent extraction and to identify the sugar content of the aqueous phase at different temperatures and reaction times. Methods: The liquid products obtained from accelerated solvent extraction were further analyzed for the total sugar content and number of sugar components using the phenol-sulfuric acid method and gas chromatography–mass spectrometry. Results: The highest sugar contents of the FPF and OPF samples were detected at 180 °C and at reaction times of 10 min and 30 min. Further extension of the reaction time at 180 °C showed that the optimal hydrolysis durations were 50 min for FPFs and 40 min for OPFs. These results may have been due to the physical structures and compositions of the samples. Analysis of the qualitative data indicated the presence of more sugar components in the FPF sample than in the OPF sample. This result was possibly due to the presence of unique and unidentified sugar components in the OPF sample. Conclusions: Hydrothermal processing via accelerated solvent extraction is a promising solution for the hydrolysis and fractionation of oil palm biomass to extract total sugars. Graphic Abstract: [Figure not available: see fulltext.].