An Overview on Pretreatments for the Production of Cassava Peels-based Xyloligosaccharides: State of Art And Challenges

• Published in: Waste and biomass valorization Vol. 14; no. 7; pp. 2115 - 2131
• Main Authors: Rogoski, William, Pereira, Gabriela N., Cesca, Karina, de Oliveira, Débora, de Andrade, Cristiano José
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-07-2023; Springer Nature B.V
• Subjects: Agricultural wastes; Bioconversion; Biomass; Biorefineries; Cassava; Cellulose; Chemical bonds; Engineering; Environment; Environmental Engineering/Biotechnology; Hemicellulose; Industrial Pollution Prevention; Industrial wastes; Ionic liquids; Lignin; Lignocellulose; Pretreatment; Renewable and Green Energy; Review; Steam explosions; Thermal plasmas; Waste Management/Waste Technology; Xylan; Pretreatments; Enzymatic hydrolysis; Cassava peel; Biorrefinery; Xylooligosaccharides
• ISSN: 1877-2641; 1877-265X
• DOI: 10.1007/s12649-023-02044-4

The valorization of agroindustrial wastes has drawn attention, since there is an increasing demand for energy aligned with obtaining bioproducts with higher added-value. In this regard, the residues generated during cassava processing are practically unexplored materials with enormous potential for bioconversion. Cassava peel is a lignocellulosic material that can be treated to remove components such as lignin and starch in order to produce hemicellulosic-based compounds. Different classical pretreatments can be used on cassava peel, in particular alkaline, acidic and hydrothermal, and modern ones such as ultrasonic, microwave and steam explosion. In addition, environmentally friendly techniques such as non-thermal plasma and ionic liquids are promising pretreatments. In general, pretreatments are used to modify the lignocellulosic chemical structure of wood biomass, i.e., physical, chemical, and biological pretreatments change the structure of lignin by breaking its chemical bonds, exposing the internal content (cellulose and hemicellulose), making it possible to obtain hemicellulosic-based bioproducts such as xylooligosaccharides (XOS). XOS are prebiotics that can be obtained from xylan-rich sources such as cassava peels and other biomasses. In this context, this review aims to critically discussed the current production of XOS based on cassava peels, including the most promising and efficient pretreatments applied on lignocellulosic wastes to obtain higher value-added bioproducts. In addition, it addresses the challenges on the change of lignocellulosic chemical structures of different biomass. Regarding traditional alkaline pretreatments, there are some advantages, such as high yield in XOS production, low by-product formation, high lignin removal yield and milder operating conditions. Thus, the use of agro-industrial wastes is a promising strategy that encompasses biorefinery concepts, such as the bioconversion of cassava peels to XOS.
Graphical Abstract