FT-IR Investigation of Cell Wall Polysaccharides from Cereal Grains. Arabinoxylan Infrared Assignment

Abstract

The FT-IR fingerprint of wheat endosperm arabinoxylan (AX) was investigated using a set of polysaccharides exhibiting variation of their degree of substitution and xylo-oligosaccharides comprising xylose units mono- or disubstituted by arabinose residues. Substitution of the xylose backbone by arabinose side units was more particularly studied in the 1000-800 cm(-1) spectral region, by taking advantage of second-derivative enhancement. The 920-1020 cm(-1) spectral region revealed two absorption bands at 984 and 958 cm(-1), the intensities of which varied according to the degree of substitution. Whereas the intensity of the band at 958 cm(-1) increased with the degree of substitution, that at 984 cm(-1) decreased. The second-derivative spectral data of xylo-oligosaccharides indicated that these changes could be attributed to substitution of the xylan backbone by arabinose residues, and the band at 958 cm(-1) was ascribed to the presence of disubstituted xylose residues. Principal component analysis of FT-IR spectra of model mixtures of AX, beta-glucans, and arabinogalactans suggested that it is possible to evaluate the relative proportions of the polymers and degree of substitution of AX in complex mixtures such as the cell wall of cereal grains.

Composite Films of Arabinoxylan and Fibrous Sepiolite: Morphological, Mechanical, and Barrier Properties

“…The spectrum of neat RAX ( Figure 6) shows a strong absorption band at 1042 cm −1 , which is due to C-OH bending. 35,36 A weak absorption band at 900 cm −1 is characteristic of β-(1→4) glycosidic linkages between the xylose units in the RAX structure. A low intensity amide I absorption band appears at approximately 1651 cm −1 , which is consistent with a low level of protein contamination.…”

Qualitative and quantitative analysis of lignocellulosic biomass using infrared techniques: A mini-review

“…Similar to the data analysis in NIR study, Tamaki and Mazza [89] employed FTIR-PLS to investigate carbohydrate content and lignin as well as extractives, and the results showed good or excellent predictive ability [90]. Along with PCA, FTIR was used for investigating the fine structural features of arabinoxylan in wheat, although the removal of starch was necessary because of its overlapped bands with arabinoxylan [91]. Allison et al [92] suggested that nitrogen content and alkali index in energy grass could be predicted accurately with FTIR-PLS.…”

Eletroflotação De Partículas Finas De Hematita Em Célula Modificada De Partridge Smith Usando Rhodococcus Opacus Como Biorreagente

“…A partir desta técnica consegue-se identificar diferentes grupos funcionais presentes nos microrganismos. Vários estudos foram realizados sobre a caracterização da composição de diferentes microrganismos (Robert et al, 2005;Garip et al, 2009;Ammanann e Brandl, 2011;Ramos-Escobedo et al, 2016). Bueno et al (2011) caracterizaram a composição da bactéria R. opacus (Tabela 9).…”

“…(Banyay et al, 2003;Bueno et al, 2008;Garip et al, 2009). Também é possível observar as bandas de menor intensidade de 2924 e 2853 cm -1 pertencentes às vibrações assimétricas e simétricas dos radicais CH 2 que estão presentes nos lipídeos, proteínas, carboidratos e ácidos nucléicos (Melin et al, 2004;Robert et al, 2005;Bueno et al, 2008). Por outro lado, a banda de absorção próxima a 1746 cm -1 corresponde à vibração do estiramento do grupo funcional C=O encontrado em lipídeos e triglicerídeos (Garip et al, 2009).…”

“…A banda de absorção 1464 cm -1 pertence à vibração simétrica dos radicais PO presentes nos fosfolipídios e ácidos nucléicos (Helm e Naumann, 1995;Robert et al, 2005;Bueno et al, 2008;Garip et al, 2009 PO (Koroleva et al, 2012). O oleato de sódio é um coletor orgânico convencional muito usado na flotação de minérios de ferro (Yin, et al, 2011;Rath et al, 2014: Sahoo et al, 2016Abaka-Wood et al, 2016) …”