Optimization of alkali-catalyzed organosolv treatment of spent coffee grounds for obtaining polysaccharides
Year: 2024
Type: article
Abstract: The coffee industry is growing rapidly and generating increasing amounts of spent coffee grounds annually. Spent coffee grounds contain high levels of polysaccharide, which needs in-depth research to obtain and transform into value-added products. This study was carried out to optimize the alkali-catalyzed organosolv treatment of spent coffee grounds to enrich the polysaccharide content. A three-factor central composite design of the response surface model was used to optimize the treatment variables including reflux time, NaOH, and acetone concentration to yield the highest polysaccharide level. As a result, the maximum polysaccharide content was 73.13% obtained at a reflux time of 4.5 h, 62% acetone with 0.91% NaOH. The polysaccharide-rich material from spent coffee ground was composed of 39.37% mannan, 10.40% glucan, and 9.33% galactan. Partial removal of lignin and protein was observed during the treatment. Enzymatic hydrolysis of the spent coffee polysaccharides released the highest reducing sugars of 5583 mg/L using an enzyme cocktail containing 4% of cellulase and 1% of mannanase after 96 h. The enzymatic hydrolysate contained 3190 mg/L mannose and 1790 mg/L glucose, showing a feasible transformation of spent coffee polysaccharides.
Authors: Duong T. T. Nguyen, Sang V. Nguyen, Anh. T. V. Nguyen, Ly T. P. Trinh, Dong N. T. Le
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4405698487