Synergistic microwave and acidic deep eutectic solvent-based pretreatment of Theobroma cacao pod husk biomass for xylooligosaccharides production

Aditya Yadav; Vishal Sharma; Mei-Ling Tsai; Diksha Sharma; Parushi Nargotra; Chiu-Wen Chen; Pei-Pei Sun; Cheng-Di Dong

doi:10.1016/j.biortech.2024.130702

Synergistic microwave and acidic deep eutectic solvent-based pretreatment of Theobroma cacao pod husk biomass for xylooligosaccharides production

Bioresour Technol. 2024 Apr 13:400:130702. doi: 10.1016/j.biortech.2024.130702. Online ahead of print.

Authors

Aditya Yadav¹, Vishal Sharma¹, Mei-Ling Tsai², Diksha Sharma¹, Parushi Nargotra², Chiu-Wen Chen³, Pei-Pei Sun², Cheng-Di Dong⁴

Affiliations

¹ Department of Seafood Science, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan; Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan.
² Department of Seafood Science, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan.
³ Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan; Institute of Aquatic Science and Technology, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan.
⁴ Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan; Institute of Aquatic Science and Technology, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan. Electronic address: cddong@nkust.edu.tw.

PMID: 38615968
DOI: 10.1016/j.biortech.2024.130702

Abstract

The bioconversion of lignocellulosic biomass into novel bioproducts is crucial for sustainable biorefineries, providing an integrated solution for circular economy objectives. The current study investigated a novel microwave-assisted acidic deep eutectic solvent (DES) pretreatment of waste cocoa pod husk (CPH) biomass to extract xylooligosaccharides (XOS). The sequential DES (choline chloride/citric acid, molar ratio 1:1) and microwave (450W) pretreatment of CPH biomass was effective in 67.3% xylan removal with a 52% XOS yield from total xylan. Among different XOS of varying degrees of polymerization, a higher xylobiose content corresponding to 69.3% of the total XOS (68.22 mg/g CPH) from liquid fraction was observed. Enzymatic hydrolysis of residual xylan from pretreated CPH biomass with low commercial xylanase (10 IU/g) concentration yielded 24.2% XOS. The MW-ChCl/citric acid synergistic pretreatment approach holds great promise for developing a cost-effective and environmentally friendly method contributing to the sustainable production of XOS from agricultural waste streams.

Keywords: Acidic DES pretreatment; Circular economy; Cocoa pod husk; Enzymatic hydrolysis; Xylooligosaccharides.