Improved xylooligosaccharides production from xylan extracted using ultrasound-assisted alcoholic deep eutectic solvent pretreatment of pineapple leaf waste
Diksha Sharma, Vishal Sharma, Mei‐Ling Tsai, Aditya Yadav, Parushi Nargotra, Peipei Sun, Chiu‐Wen Chen, Cheng‐Di Dong
Abstract
The management of agricultural wastes from agro-food processing industries is critical for sustainability , with growing attention towards utilizing green bioconversion processes. Pineapple leaf (PL) waste, a rich source of hemicellulose , is a potential feedstock for industrial xylooligosaccharides (XOS) production for better health care. In the present work, a combined alcoholic deep eutectic solvent (DES) and ultrasound (50 % amplitude, 20 min) fractionation approach was applied to PL waste, resulting in improved xylan extraction (180 mg/g biomass) from the liquid fraction of the pretreated mixture. The DES (choline chloride/ethylene glycol, 1:2) was recycled for five cycles, maintaining 93 % extraction efficiency. Biorefining of XOS from xylan extracted by ethanol precipitation of pretreated PL liquid hydrolysate and dilute nitric acid (4 %) for 1 h at 100 ℃ hydrolysis gave a maximum XOS yield (66.6 mg/g biomass) with xylobiose (24.3 mg/g biomass) as the most significant XOS. Mass balance analysis of the bioprocess revealed the effective conversion of waste biomass into bioproducts , ensuring minimal waste and maximum resource utilization. The integrated DES-ultrasound pretreatment substantiates the potential for sustainable XOS production from pineapple waste with significant biological activity .