title: Microwave-assisted organic acid extraction of lignin from bamboo: structure and antioxidant activity investigation.
abstract: Microwave-assisted extraction in organic acid aqueous solution (formic acid/acetic acid/water, 3/5/2, v/v/v) was applied to isolate lignin from bamboo. Additionally, the structural features of the extracted lignins were thoroughly investigated in terms of C₉ formula, molecular weight distribution, FT-IR, (1)H NMR and HSQC spectroscopy. It was found that with an increase in the severity of microwave-assisted extraction, there was an increase of phenolic hydroxyl content in the lignin. In addition, an increase of the severity resulted in a decrease of the bound carbohydrate content as well as molecular weight of the lignin. Antioxidant activity investigation indicated that the radical scavenging index of the extracted lignins (0.35-1.15) was higher than that of BHT (0.29) but lower than that of BHA (3.85). The results suggested that microwave-assisted organic acid extraction provides a promising way to prepare lignin from bamboo with good antioxidant activity for potential application in the food industry.
authors.affiliation: Institute of Biomass Chemistry and Technology, Beijing Forestry University, 100083 Beijing, China.
authors.forename: Ming-Fei
authors.initials: MF
authors.lastname: Li
authors.affiliation: Institute of Biomass Chemistry and Technology, Beijing Forestry University, 100083 Beijing, China.
authors.forename: Shao-Ni
authors.initials: SN
authors.lastname: Sun
authors.affiliation: Institute of Biomass Chemistry and Technology, Beijing Forestry University, 100083 Beijing, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Xu
authors.affiliation: Institute of Biomass Chemistry and Technology, Beijing Forestry University, 100083 Beijing, China; State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, 510640 Guangzhou, China.
authors.forename: Run-Cang
authors.initials: RC
authors.lastname: Sun
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D005591:Chemical Fractionation / Q000379:methods; D005561:Formates / Q000737:chemistry; D008031:Lignin / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D008872:Microwaves; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D006109:Poaceae / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000975:Antioxidants; D005561:Formates; D010936:Plant Extracts; C030544:formic acid; D008031:Lignin; D019342:Acetic Acid