Characterization Of Arabinoxylans Research Articles

Recycling of wheat gluten wastewater: separation, characterisation, and solution rheology of arabinoxylans

SummaryA significant volume of gluten production wastewater, containing arabinoxylan, is generated during wheat processing, presenting an underutilised resource. In this study, water‐extractable arabinoxylan (WEAX) was obtained from this wastewater through water extraction and alcohol precipitation, followed by purification, and its chemical and rheological properties were subsequently investigated. The analysis revealed a mean molecular weight of 4.57 × 104 Da for WEAX, with arabinose (38.08%) and xylose (43.77%) as the predominant monosaccharides. Notably, the sample exhibited characteristic structural properties of arabinoxylan, as confirmed by FT‐IR spectra. Scanning electron microscopy further revealed a heterogeneous solid morphology, comprising filamentous flake and spherical structures. Moreover, WEAX demonstrated favourable thermal stability and revealed shear‐thinning behaviour, as well as weak gelation, as evidenced by thermogravimetry, differential scanning calorimetry, and rheological analysis. This study not only presents a novel approach for the resource treatment of wheat gluten production wastewater but also contributes new insights into the characterisation of arabinoxylan.

Extraction and characterisation of arabinoxylan from brewers spent grain and investigation of microbiome modulation potential

PurposeBrewers’ spent grain (BSG) represents the largest by-product of the brewing industry. Its utilisation as an animal feed has become less practical today; however, its high fibre and protein content make it a promising untapped resource for human nutrition. BSG contains mainly insoluble fibre. This fibre, along with protein, is trapped with the complex lignocellulosic cell structure and must be solubilised to release components which may be beneficial to health through modulation of the gut microbiota.MethodsIn this study, the application of a simultaneous saccharification and fermentation process for the extraction and solubilisation of arabinoxylan from BSG is demonstrated.ResultsProcessing of the BSG was varied to modulate the physicochemical and molecular characteristic of the released arabinoxylan. The maximum level of arabinoxylan solubilisation achieved was approximately 21%, compared to the unprocessed BSG which contained no soluble arabinoxylan (AX). Concentration of the solubilised material produced a sample containing 99% soluble AX. Samples were investigated for their microbiome modulating capacity in in-vitro faecal fermentation trials. Many samples promoted increased Lactobacillus levels (approx. twofold). One sample that contained the highest level of soluble AX was shown to be bifidogenic, increasing the levels of this genus approx. 3.5-fold as well as acetate (p = 0.018) and propionate (p < 0.001) production.ConclusionThe findings indicate that AX extracted from BSG has prebiotic potential. The demonstration that BSG is a source of functional fibre is a promising step towards the application of this brewing side-stream as a functional food ingredient for human nutrition.

Preparation and characterisation of arabinoxylan and (1,3)(1,4)‐β‐glucan alternating multilayer edible films simulated those of wheat grain aleurone cell wall

SummaryVarious observations show a lamellar organisation of wheat aleurone cell walls, that likely acted as barriers to regulate the water diffusion rate in wheat grains. In this study, arabinoxylan (AX) and (1,3)(1,4)‐β‐glucan (BG) alternating multilayer films which mimic cell wall of aleurone structure were prepared. Twenty layers of alternating multilayer films of AX/BG were prepared with individual thicknesses of 20 µm. The water diffusion and water mobility of the films were determined using dynamic vapour sorption and time‐domain nuclear magnetic resonance spectroscopy. The AX/BG alternating multilayer films exhibited unique mechanical and hydration properties, which could be explained by their unique nanostructure and microporosity. The edible films with this structure were found to exhibit high ultimate stress and ultimate strain, and low rates of water diffusion.

Characterization of arabinoxylan degrading enzymes during wheat malting

In this paper the arabinoxylanase activities and the content of water-extractable arabinoxylans (WEAXs) including their degradation products in wheat Yannong 24 during the malting process were studied. The results showed that the endo-β-1,4-xylanase activity had a large increase during the steeping process, endo-β-1,4-xylanase and α-L-arabinofuranosidase achieved the highest activity on day 4 of germination. During malt kilning, endo-β-1,4-xylanase and α-L- arabinofuranosidase were not heat stable, and the activity decline rate were 65.88% and 69.58%; whereas malt β-D-xylosidase was resistant to heat and it’s activity decline rate was only 18.74%. It is during steeping and the first day of germination that the content of WEAXs and it’s degradation products (WEAXs+DP) dramatically increased, and this corresponded to the greater improvement of endo-β-1,4-xylanase activity in the same phase. The WEAXs+DP content has a very significant positive correlation with the endo-β-1,4-xylanase activity (0.892, p&lt;0.01). It can be indicated that endo-β-1,4-xylanase is the main degrading enzyme in the degradation of WUAXs and the increase of the WEAXs content during steeping and the first day of wheat germination.

Isolation and characterization of arabinoxylans from wheat bran and study of their contribution to wheat flour dough rheology

The study was aimed to evaluate the yield and sugar composition of water-extractable (WE) and alkali extractable (AE) Hemi-A, Hemi-B and oligosaccharides (Oligo) fractions isolated from bran of four wheat varieties and their relationship with dough rheology. Wheat bran from all varieties were rich in protein content (12.45–16.97%). The yield of WE-Hemi-A, WE-Hemi-B and WE-Oligo were lower than the yield of AE-Hemi-A, AE-Hemi-B and AE-Oligo, for all varieties. Sugar composition of fractions determined by high-performance anion exchange chromatography with pulsed amperometric detector (HPAEC-PAD), showed sugars: rhamnose, galactose, glucose, galacturonic acid and glucuronic acid, in addition to the typical arabinoxylan containing arabinose and xylose are present in all wheat bran varieties. HD-3086 and HD-2947 wheat varieties which yielded a viscoelastic dough with high G' and G" values (indicative of good dough-making characteristics), had a higher percent of AE-Hemi-B and both WE-Oligo and AE-Oligo than C-306 and HS-490 wheat varieties.

Phenolic compounds, antioxidant capacity and gelling properties of glucoarabinoxylans from three types of sorghum brans

Arabinose to xylose ratio (A/X), phenolics, antioxidant capacity and gelling properties were evaluated in glucoarabinoxylans (GAX) extracted from white (W-GAX), red (R-GAX) and high tannin (T-GAX) sorghum brans (SB). The characterization of arabinoxylans from corn fiber (CFAX) was used as benchmark. Sorghum GAX had higher branched structure (A/X 1.08–1.41) than CFAX (0.59). Nine 3-deoxyanthocyanins (3-DAs) were identified in SB and two glycosylated forms remained associated to the R-GAX and T-GAX extracts. T-GAX was the only that contained tannins (0.41 mg catechin equivalents (CE)/g dry basis (db)) and exerted the highest antioxidant capacity (81.75 mM Trolox equivalents (TE)/g db) followed by R-GAX (48.49 mM TE/g db), which contained the highest amount of 3-DAs (0.11 mg Luteolinidin equivalents (Lut eq)/g db), and W-GAX (35.45 mM TE/g db) that was not significantly different from the CFAX (25.83 mM TE/g db). Among sorghums, only the W-GAX gelled but it formed a weaker gel compared to CFAX likely due to its lower hydroxycinnamic acids (HCA) concentration. The presence of 3-DAs in the structure of R-GAX and T-GAX affected negatively their solubility and gelling properties. The different SB showed potential as sources of GAX with antioxidant capacity.