Fermented Cassava Residue Lignin Prepared by Sequential Acid Steam-Explosion and Hot-Alkaline Treatment and Its Antioxidant Properties

摘要

Fermented cassava residue (FCR) is a solid waste generated in cassava-based ethanol production that constitutes a major environmental challenge and wastes a natural resource. In the present study, a process involving sequential acid steam-explosion and hot-alkaline treatment was developed to prepare an antioxidant lignin in high yield and purity from FCR. Two-dimensional NMR analysis indicates that FCR lignin belongs to a guaiacyl/syringyl/hydroxyphenyl (G/S/H) class of lignin. P-31 NMR analysis, after hydroxyl group phosphorylation, indicates that phenolic hydroxyl in FCR lignin attributable to mostly G-OH. One FCR lignin (No. 3) possessed the antioxidant activity similar to that of butylated hydroxytoluene. This FCR lignin may have potential applications as a food antioxidant or in other industrial processes as an antioxidant. Graphic The present study provided an efficient process of sequent acid steam-explosion and hot-alkaline treatment to improve the added value of fermented cassava residue (FCR). @@@ [GRAPHICS] @@@ .

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