Hemicellulose from cane bagasse as assessed by OLIMP MALDI-TOF/MS (original) (raw)
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Carbohydrate Polymers, 2014
Developing optimum treatment and separation procedures for hemicellulose components of lignocellulosic biomass could be useful in ethanol fermentation processes and obtaining pure hemicelluloses as biopolymers. Sugarcane bagasse analyses indicate that xylose is the major hemicellulose component constituting 17.7% of dry bagasse weight. In this study the effects of treatment conditions such as time, temperature and pressure on the yields of extracted hemicelluloses were studied. The optimum conditions were achieved at 180 • C for 30 min and 1 MPa pressure, with the yield of xylose reaching to 85% and the concentrations of sugar degradation products such as HMF and furfural remaining minimal at 0.95 and 0.07 g/L, respectively. Further, isolation of hemicelluloses from extracted hemicelluloses solutions was performed using Alfa Laval M20 membrane filtration system in two steps: (1) concentration of high molar mass hemicelluloses by ultrafiltration; and (2) separation of low molar mass hemicelluloses and oligomeric sugars by nanofiltration. The isolated hemicelluloses with the optimum pretreatment conditions were characterized by FT-IR and 13 C NMR techniques, resulting in agreement with typical spectra of xylan-type hemicelluloses.
Efficient extraction of bagasse hemicelluloses and characterization of solid remainder.pdf
h i g h l i g h t s pH pre-corrected was studied and obtained high molecular weight of hemicellulose. Response surface model was established to optimize the extraction process. The yields of hemicellulose extracted increased from 33.77% to 43.38%. The species composition and purity (xylose 84.11%) of HE was analyzed by HPLC. The biggest balance between solid remainder and dissolved solid was obtained.
Comparative Study of Hemicelluloses Obtained by Graded Ethanol Precipitation from Sugarcane Bagasse
Journal of Agricultural and Food Chemistry, 2009
The sequential treatment of dewaxed sugarcane bagasse with H 2 O and 1 and 3% NaOH at a solid to liquid ratio of 1:25 (g mL -1 ) at 50°C for 3 h yielded 74.9% of the original hemicelluloses. Each of the hemicellulosic fractions was successively subfractionated by graded precipitation at ethanol concentrations of 15, 30, and 60% (v/v). Chemical composition, physicochemical properties, and structures of eight precipitated hemicellulosic fractions were elucidated by a combination of sugar analysis, nitrobenzene oxidation of bound lignin, molecular determination, Fourier transform infrared (FT-IR), 1 H and 13 C nuclear magnetic spectroscopies, and thermal analysis. The results showed that the sequential treatments and graded precipitations were very effective on the fractionation of hemicelluloses from bagasse. Comparison of these hemicelluloses indicated that the smaller sized and more branched hemicelluloses were extracted by the hot water treatment; they are rich in glucose, probably originating from R-glucan and pectic polysaccharides. The larger molecular size and more linear hemicelluloses were dissolved by the alkali treatment; they are rich in xylose, principally resulting from L-arabino-(4-O-methylglucurono)-D-xylans. In addition, noticeable differences in the chemical composition and molecular weights were observed among the graded hemicellulosic subfractions from the water-soluble and alkali-soluble hemicelluloses. The Ara/Xyl ratio increased with the increment of ethanol concentration from 15 to 60%, and the arabinoxylans with higher Ara/Xyl ratios had higher molecular weights. There were no significant differences in the structural features of the precipitated hemicellulosic subfractions, which are mainly constituted of L-arabino-(4-O-methyl-D-glucurono)xylan, whereas the difference may occur in the distribution of branches along the xylan backbone.
Fractionation and structural characterization of LiCl–DMSO soluble hemicelluloses from tomato
Carbohydrate Polymers, 2013
To prepare and explore the structure of native hemicellulose from tomato, extraction of the natively acetylated polysaccharides was achieved from partially depectinated cell walls by DMSO doped with LiCl. DEAE anion exchange chromatography of the LiCl-DMSO extract allowed the removal of residual acidic pectin and the isolation of acetylated glucuronoxylan. The hemicellulose neutral fraction from the anion exchanger was fractionated by size exclusion chromatography into xyloglucan (XyG) and galactoglucomannan (GgM) either as single major constituents or as mixtures of both. Residual hemicellulose in the cell wall was extracted by 4.0 M and not 1.0 M KOH. The fine structure of all LiCl-DMSO fractions and alkali extracts was assessed by coupling β-glucanase, β-mannanase and β-xylanase enzymatic degradations to the analysis of the resulting fragments by HPAEC and MALDI-TOF mass spectrometry. This approach revealed substitutions in part of the GgM fractions by pentose residues, presumably arabinose and/or xylose occurring in highly substituted block domains. It also demonstrated a different glucanase hydrolysis profile from 4.0 M KOH compared to LiCl-DMSO soluble fractions. The present extraction and purification scheme allow the recovery of several populations of acetylated hemicellulose families which emphasize the structural diversity and complexity of these polysaccharides.
Covalent lignin-carbohydrate linkages between lignin and carbohydrates have been suggested to be a major obstacle to complete delignification of biomass feedstocks during chemical processing, e.g. pulping or enzymatic hydrolysis of the biomass to release sugars for ethanol production. The current study is aimed at developing an understanding of the structural composition and the behaviour of lignin carbohydrate complexes (LCCs) in sugarcane bagasse, a potential raw material for bio-ethanol production. Hemicelluloses were pre-extracted prior to soda AQ pulping with the aim of preserving it for further use instead of losing it in the black liquor (Value Prior Pulping or VPP). LCCs from the hemicelluloses pre-extracted soda AQ pulps as well, as non-extracted materials i.e. controls, were isolated and quantified. Mainly, two types of LCCs were identified: the xylan-lignin and glucan-lignin-xylan complexes. FTIR and GPC analyses of LCC fractions confirmed that the ester bonds of LCCs wer...
Preparation and Characterization of Hemicellulose Films from Sugarcane Bagasse
Materials
Hemicellulose is one of the most common polysaccharides found in nature. Its use as a green and sustainable raw material for industries is desirable. In this work, an alkaline-alcoholic method was used to extract hemicelluloses from sugarcane bagasse. After extraction, films with 2%, 3% and 4% (w/v) hemicellulose were produced. The films’ morphology, thickness, water solubility, tensile properties and thermal stability were evaluated. The Fourier Transform Infrared Spectroscopy (FTIR) results reveal that the method used removes the hemicellulose from bagasse with a low concentration of lignin. The films presented a compact and dense structure with uniformity in thickness associated with higher solubility in water. The increase in hemicellulose content increased tensile strength, but reduced the tensile strain of the films. Thermogravimetric analysis indicated that the increase in hemicellulose content reduced the films’ thermal stability. Thus, these films may act as useful, biodegr...
Covalent lignin-carbohydrate linkages between lignin and carbohydrates have been suggested to be a major obstacle to complete delignification of biomass feedstocks during chemical processing, e.g. pulping or enzymatic hydrolysis of the biomass to release sugars for ethanol production. The current study is aimed at developing an understanding of the structural composition and the behaviour of lignin carbohydrate complexes (LCCs) in sugarcane bagasse, a potential raw material for bio-ethanol production. Hemicelluloses were pre-extracted prior to soda AQ pulping with the aim of preserving it for further use instead of losing it in the black liquor (Value Prior Pulping or VPP). LCCs from the hemicelluloses pre-extracted soda AQ pulps as well, as non-extracted materials i.e. controls, were isolated and quantified. Mainly, two types of LCCs were identified: the xylan-lignin and glucan-lignin-xylan complexes. FTIR and GPC analyses of LCC fractions confirmed that the ester bonds of LCCs were degraded through hemicelluloses pre-extraction, leading to a significant change in their structure. This in turn resulted in more cellulose being more accessible to pulping and enzymatic hydrolysis respectively. The study showed that alkaline pre-extracted biomass materials have a more amenable structure to processing, as a result of the disruption of the unreactive LCCs in the residual lignin. Further, alkaline hemicelluloses pre-extraction in combination with soda AQ holds more promise for VPP due to reduced LCCs. This could have a positive impact in downstream processes such as bleaching.
Proceedings of the International Society of Sugar Cane Technologists 30 : 661-664. (2019), 2019
Knowledge of cell-wall composition in sugarcane hybrids could be used for the selection of cultivars with high bagasse digestibility in order to improve sugar release in 2G ethanol production. Cell-wall components of 76 hybrids of a sugarcane cross, their parents and two highfibre genotypes were analyzed. The Van Soest method was used to determine cellulose, hemicellulose and acid detergent lignin contents (ADL). Spectroscopic acetyl bromide lignin (ABS) was also determined. A correlation analysis was performed with major cell-wall polymers and agronomic traits. Despite the minor differences observed between parental lines' cell-wall composition, genotypes with high cellulose and low lignin content were identified in the progeny. Differences among them depended on the method used for lignin measurement. The ADL mean was 43% lower than the ABS mean, in agreement with lignin losses during acid detergent treatment previously reported. There was no correlation between ADL and ABS assays. Bagasse of genotypes with higher stalk weights was associated with higher cellulose content and lower ADL content. Saccharification studies are needed to validate lignin assessment methodologies to be used as bioenergy cultivar selection tools.
Characteristics of the Water-and Alkali-Soluble Hemicelluloses Fractionated by Sequential.pdf
Sweet maize stems were treated with hot water and potassium hydroxide to fractionate hemicellulosic polymers. The results showed that the water-soluble hemicelluloses were mainly composed of glucose (27.83%), xylose (27.32%), and galactose (16.81%). In comparison, alkali-soluble hemicelluloses fractionated by acidification and a graded ethanol solution (10%, 20%, 35%, 50%, 65%, and 80%) were mainly composed of xylose (69.73 to 88.62%) and arabinose (5.41 to 16.20%). More highly branched hemicelluloses tended to be precipitated in a higher concentration of ethanol solution, as revealed by the decreasing xylose to arabinose ratio from 16.43 to 4.21. Structural characterizations indicated that alkali-soluble hemicelluloses fractionated from sweet maize stems were mainly arabinoxylans. The results provided fundamental information on hemicelluloses composition and structure and their potential utilization in the fields of biofuels, biochemicals, and biomaterials.