Isolation, Physicochemical Properties, and Structural Characteristics of Arabinoxylan from Hull-Less Barley.

Arabinoxylan (HBAX-60) was fractioned from alkaline-extracted arabinoxylan (HBAX) in the whole grain of hull-less barley (Hordeum vulgare L. var. nudum Hook. f. Poaceae) by 60% ethanol precipitation, which was studied for physicochemical properties and structure elucidation. Highly purified HBAX-60 mainly composed of arabinose (40.7%) and xylose (59.3%) was created. The methylation and NMR analysis of HBAX-60 indicated that a low-branched ß-(1→4)-linked xylan backbone possessed un-substituted (1,4-linked ß-Xylp, 36.2%), mono-substituted (ß-1,3,4-linked Xylp, 5.9%), and di-substituted (1,2,3,4-linked ß-Xylp, 12.1%) xylose units as the main chains, though other residues (α-Araf-(1→, ß-Xylp-(1→, α-Araf-(1→3)-α-Araf-(1→ or ß-Xylp-(1→3)-α-Araf-(1→) were also determined. Additionally, HBAX-60 exhibited random coil conformation in a 0.1 M NaNO3 solution. This work provides the properties and structural basis of the hull-less barley-derived arabinoxylan, which facilitates further research for exploring the structure-function relationship and application of arabinoxylan from hull-less barley.

Performance and structural comparison of hydrogels made from wheat bran arabinoxylan using enzymatic and coacervation methods as micro-and nano- encapsulation and delivery devices.

This study evaluated the structural and performance differences between arabinoglucuronoxylan micro-hydrogels that were enzymatically produced from alkaline-extracted wheat bran arabinoglucuronoxylans using recombinant α-L-arabinofuranosidase (AbfB) that selectively removes arabinose side chains, and chemically through coacervation process, as delivery devices for bioactive substances. The encapsulations of model bioactive substance, gallic acid (GA), in the hydrogels, were done either in-situ or ex-situ to identify the most effective encapsulation and delivery method. The hydrogels particle size distribution, polydispersity index, GA encapsulation efficiency, retention and release of functional GA (based on antioxidant activity) were assessed. The hydrogels formed in both coacervation and enzymatic processes had particle size ranges of 469-678 nm, which classify them as micro-hydrogels. However, the latter were monodispersed with polydispersity index (PdI) < 0.4 compared to the former with PdI > 0.7. In addition, enzymatically produced hydrogels attained higher zeta potential (-8.8 mV) and retained and released GA with higher anti-oxidant capacity (91%) than chemically formed micro-hydrogels (zeta potential = - 3.3 mV and antioxidant capacity = 80%). However, GA encapsulation efficiencies (72% in-situ and 68% ex-situ) were higher in chemically formed micro-hydrogels than enzymatically produced micro-hydrogels (59% in-situ and 52% ex-situ). The in-situ encapsulated GA experienced less initial burst during sustained release of 8 h compared to ex-situ encapsulation. Overall, enzymatic modification process and in-situ encapsulation were the most effective methods for production of arabinoglucuronoxylan micro-hydrogels delivery devices and for encapsulation of the GA, respectively, because of maintaining functional GA upon release and having the potential to customize the structural and functional properties of the micro-hydrogels.

Experimental and Theoretical Evaluation of the Solubility/Insolubility of Spruce Xylan (Arabino Glucuronoxylan).

The molecular solubility of softwood arabinoglucuronoxylan (AGX) has been thoroughly investigated, and it has been shown that the chemical and physical structures of the extracted hemicellulose are not significantly influenced by different purification steps, but a transient molecular solubility of AGX was observed in aqueous media at low concentrations (1 g/L) when the dissolved macromolecules had a hydrodynamic diameter of up to 10 nm. A phase separation was detected when the concentration was increased to 15 g/L leading to an association of the smaller molecules into fractal structures with a considerably larger diameter, even though the dispersions were still transparent to ocular inspection. Dynamic Light Scattering and Cryo-Transmission Electron Microscopy showed dimensions in the range of 1000 nm. The phase separation of the sample was further characterized by estimating the χ-interaction parameter of AGX in water using the Flory-Huggins theory, and the results supported that water is a poor solvent for AGX. This behavior is crucial when films and hydrogels based on these biopolymers are made, since the association will dramatically affect barrier and mechanical properties of films made from these materials.

Thiolation of arabinoxylan and its application in the fabrication of pH-sensitive thiolated arabinoxylan grafted acrylic acid copolymer.

Current research work was conducted to synthesize Thiol modified arabinoxylan and its application in fabrication of hydrogel. Thioglycolic acid was esterified with arabinoxylan to prepare Thiolatedarabinoxylan. Appearance of peak at 2533.34 cm-1 in FTIR and thiol content showed successful thiolation. The pH-dependent Thiolatedarabinoxylan/acrylic acid (TAX/AA) hydrogels of perindopril erbumine were prepared via free-radical co-polymerization. Perindopril erbumine (PE) was employed as model drug. Different batches with different feed ratio of TAX, AA, and MBA were prepared and their influence on swelling, solvent penetration, and consequent drug release was investigated. Swelling coefficients increased with increase in pH. TAX/AA hydrogels were characterized by Fourier-transform infrared spectroscopy (FT-IR), Thermal Analysis (TA), X-Ray diffraction (XRD), and scanning electron microscope (SEM). Dissolution studies were performed at pH 1.2 and 7.4 in which drug release showed direct correlation with TAX and AA ratio. In vivo studies showed that Cmax of TAX-co-AA based hydrogel was 81.57 ± 0.35 ng/ml which was maintained for a longer time after its administration. All the results of in vivo studies were significant and TAX-co-AA based hydrogel enhances the bioavailability of perindopril erbumine.

Xylan from Pineapple Stem Waste: a Potential Biopolymer for Colonic Targeting of Anti-inflammatory Agent Mesalamine.

We have successfully conjugated mesalamine (5-aminosalicylic acid, 5-ASA) with xylan, a biopolymer isolated from pineapple stem waste, to form xylan-5-ASA conjugate. The biopolymer was used to provide colon-targeting properties for 5-ASA, a golden standard anti-inflammatory agent commonly used for ulcerative colitis treatment. A series of data from FTIR spectroscopy, UV-Vis spectrophotometry, and HPLC confirmed the xylan-5-ASA conjugate formation. To ensure successful colon targeting properties, in vitro and in vivo drug release studies after oral administration of xylan-5-ASA conjugate to Wistar rats were performed. Xylan-5-ASA conjugate was able to retain 5-ASA release in the upper gastrointestinal tract fluid simulation but rapidly released 5-ASA in the rat colon fluid simulation. In vivo release profile shows a very low peak plasma concentration, reached at 6 h after xylan-5-ASA conjugate administration. The delayed release and the lower bioavailability of 5-ASA from xylan-5-ASA conjugate administration compared to free 5-ASA administration confirmed the successful local colon delivery of 5-ASA using xylan-5-ASA conjugate. The administration of xylan-5-ASA conjugate also exhibited greater efficacy in recovering 2,4,6-trinitrobenzene sulfonic acid-induced colon ulcer compared to free 5-ASA administration. Taken together, xylan isolated from pineapple stem waste is promising to obtain colon targeting property for 5-ASA.

Constructing arabinofuranosidases for dual arabinoxylan debranching activity.

Enzymatic conversion of arabinoxylan requires α-L-arabinofuranosidases able to remove α-L-arabinofuranosyl residues (α-L-Araf) from both mono- and double-substituted D-xylopyranosyl residues (Xylp) in xylan (i.e., AXH-m and AXH-d activity). Herein, SthAbf62A (a family GH62 α-L-arabinofuranosidase with AXH-m activity) and BadAbf43A (a family GH43 α-L-arabinofuranosidase with AXH-d3 activity), were fused to create SthAbf62A_BadAbf43A and BadAbf43A_SthAbf62A. Both fusion enzymes displayed dual AXH-m,d and synergistic activity toward native, highly branched wheat arabinoxylan (WAX). When using a customized arabinoxylan substrate comprising mainly α-(1 → 3)-L-Araf and α-(1 → 2)-L-Araf substituents attached to disubstituted Xylp (d-2,3-WAX), the specific activity of the fusion enzymes was twice that of enzymes added as separate proteins. Moreover, the SthAbf62A_BadAbf43A fusion removed 83% of all α-L-Araf from WAX after a 20 hr treatment. 1 H NMR analyses further revealed differences in SthAbf62A_BadAbf43 rate of removal of specific α-L-Araf substituents from WAX, where 9.4 times higher activity was observed toward d-α-(1 → 3)-L-Araf compared to m-α-(1 → 3)-L-Araf positions.

The effect of pentosanase on the solubilisation and degradation of arabinoxylan extracted from whole and refined wheat flour.

BACKGROUND: The quality improvement capability of pentosanase (Pn) for whole-wheat Chinese steamed bread (CSB) is not as efficient as that for refined CSB. However, the underlying mechanism remains to be elucidated. In this work, water-extractable arabinoxylan (WEAX) and water-unextractable solids (WUS) were extracted from whole and refined wheat flour, and then treated with Pn under the conditions similar to CSB-making. Solubilisation and degradation of arabinoxylan (AX) caused by Pn treatment were determined. RESULTS: WEAX from whole flour exhibited higher molecular weight than that from refined flour before and after the treatment with equivalent Pn. Compared with WUS from refined flour, WUS from whole flour had a much lower dissolution degree but the degradation of AX released from the WUS was more efficiently. Moreover, AX released from WUS for refined flour showed a higher Ara/Xyl ratio and the percentage of residual ferulic acid in WUS decreased more significantly. CONCLUSION: The difference in quality improvement degree for Pn in whole-wheat and refined CSB might be mainly explained by its effect on WUS. That is, Pn contributed much more to the solubilisation of WUS from refined flour but provoked degradation predominantly on AX solubilised from WUS isolated from whole flour. © 2016 Society of Chemical Industry.

Effect of Xylan Sulfates on Coagulation of Human Blood Plasma.

Sulfated derivatives of xylan (isolated from Bétula pubéscens wood) with average molecular weight ~34 kDa, sulfur content of 11.3-17.5%, a degree of substitution of 0.74-1.64 are anticoagulants of direct type of action. Antithrombin and antifactor Xa activities in three tested xylan samples did not differ and reached 30.8-31.8 and 13.5-14.3 U/mg, respectively.

Evolutionary Conservation of Xylan Biosynthetic Genes in Selaginella moellendorffii and Physcomitrella patens.

Xylan is a major cross-linking hemicellulose in secondary walls of vascular tissues, and the recruitment of xylan as a secondary wall component was suggested to be a pivotal event for the evolution of vascular tissues. To decipher the evolution of xylan structure and xylan biosynthetic genes, we analyzed xylan substitution patterns and characterized genes mediating methylation of glucuronic acid (GlcA) side chains in xylan of the model seedless vascular plant, Selaginella moellendorffii, and investigated GT43 genes from S. moellendorffii and the model non-vascular plant, Physcomitrella patens, for their roles in xylan biosynthesis. Using nuclear magentic resonance spectroscopy, we have demonstrated that S. moellendorffii xylan consists of ß-1,4-linked xylosyl residues subsituted solely with methylated GlcA residues and that xylans from both S. moellendorffii and P. patens are acetylated at O-2 and O-3. To investigate genes responsible for GlcA methylation of xylan, we identified two DUF579 genes in the S. moellendorffii genome and showed that one of them, SmGXM, encodes a glucuronoxylan methyltransferase capable of adding the methyl group onto the GlcA side chain of xylooligomers. Furthermore, we revealed that the two GT43 genes in S. moellendorffii, SmGT43A and SmGT43B, are functional orthologs of the Arabidopsis xylan backbone biosynthetic genes IRX9 and IRX14, respectively, indicating the evolutionary conservation of the involvement of two functionally non-redundant groups of GT43 genes in xylan backbone biosynthesis between seedless and seed vascular plants. Among the five GT43 genes in P. patens, PpGT43A was found to be a functional ortholog of Arabidopsis IRX9, suggesting that the recruitment of GT43 genes in xylan backbone biosynthesis occurred when non-vascular plants appeared on land.

Lignin-carbohydrate complexes from sisal (Agave sisalana) and abaca (Musa textilis): chemical composition and structural modifications during the isolation process.

MAIN CONCLUSION: Two types of lignins occurred in different lignin-carbohydrate fractions, a lignin enriched in syringyl units, less condensed, preferentially associated with xylans, and a lignin with more guaiacyl units, more condensed, associated with glucans. Lignin-carbohydrate complexes (LCC) were isolated from the fibers of sisal (Agave sisalana) and abaca (Musa textilis) according to a plant biomass fractionation procedure recently developed and which was termed as "universally" applicable to any type of lignocellulosic material. Two LCC fractions, namely glucan-lignin (GL) and xylan-lignin (XL), were isolated and differed in the content and composition of carbohydrates and lignin. In both cases, GL fractions were enriched in glucans and comparatively depleted in lignin, whereas XL fractions were depleted in glucans, but enriched in xylans and lignin. Analysis by two-dimensional Nuclear Magnetic Resonance (2D-NMR) and Derivatization Followed by Reductive Cleavage (DFRC) indicated that the XL fractions were enriched in syringyl (S)-lignin units and ß-O-4' alkyl-aryl ether linkages, whereas GL fractions have more guaiacyl (G)-lignin units and less ß-O-4' alkyl-aryl ether linkages per lignin unit. The data suggest that the structural characteristics of the lignin polymers are not homogeneously distributed within the same plant and that two different lignin polymers with different composition and structure might be present. The analyses also suggested that acetates from hemicelluloses and the acyl groups (acetates and p-coumarates) attached to the γ-OH of the lignin side chains were extensively hydrolyzed and removed during the LCC fractionation process. Therefore, caution must be paid when using this fractionation approach for the structural characterization of plants with acylated hemicelluloses and lignins. Finally, several chemical linkages (phenylglycosides and benzyl ethers) could be observed to occur between lignin and xylans in these plants.

Cereal-derived arabinoxylans as biological response modifiers: extraction, molecular features, and immune-stimulating properties.

Arabinoxylans are of significant importance to human health due to their potential to modulate both the adaptive and innate immune systems. Arabinoxylans of various structures and sources have been shown to affect different immune cells to augment a wide range of immune responses in vitro and in vivo in animals and humans. This review article discusses current research on the immune-enhancing activities of arabinoxylans and other cereal polysaccharides in relation to their structural heterogeneity. There are inconsistencies in the literature regarding the relationships between the immunomodulatory effects and the structure and source of arabinoxylans. Possible mechanisms underlying these relationships which might explain the effects of such bioactive polysaccharides are proposed.

Acute toxicity studies of a novel excipient arabinoxylan isolated from Ispaghula (Plantago ovata) husk.

PURPOSE: The arabinoxylan from Ispaghula (Plantago ovata) husk has been proven scientifically as potential excipient. However, toxicity study of the arabinoxylan is still lacking. The present study was done to investigate the acute toxicity of arabinoxylan in two animal species. METHODS: The mice were exposed to (1 g/kg, 5 g/kg, 10 g/kg) and rabbits (2.5 g/kg, 5 g/kg) of arabinoxylan orally and observed for a period of 14 days. On day 15 hematology, serum biochemistry and necropsy was performed in mice relative organ weight calculated and histological examination was carried out. Primary dermal and eye irritation tests were carried out. Cardiac effects of isolated arabinoxylan were studied on frog heart. RESULTS: The acute administration of the arabinoxylan did not produce mortality or significant changes in, water and food consumption however body weights of mice and rabbits decreased initially with a gradual increase till day 14. Internal organs relative weights were found to be normal. Hematological biochemical and histopathological examination did not show any significant (p < 0.05) change. Primary dermal and eye irritation was not observed in treated rabbits. No change in heart rate and vascular contraction was observed in frog heart. CONCLUSION: This study has shown that acute administration of arabinoxylan may be safe.

Evaluation of the prebiotic potential of arabinoxylans from brewer's spent grain.

Arabinoxylans (AX) consumption has been related to the treatment and prevention of cardiovascular diseases, type II diabetes, colorectal cancer and obesity. The beneficial health effects are conferred through gut microbiota modulation, and therefore, they have been proposed as potential slowly fermentable prebiotic candidates. As the mechanisms are not yet well understood, the prebiotic potential of AX from brewer's spent grain (BSG) has been investigated. Two types of AX from BSG (AX1 and AX2) of different length and branching averages were fermented with human faecal inocula and compared to fermented cultures containing a commercial prebiotic (fructooligosaccharide (FOS)) and cultures with no added carbohydrate (control). Results demonstrated that the AX were extensively metabolised after 48 h of fermentation. The pH decreased along fermentation and the lowest value was achieved in AX1 cultures. The production of short chain fatty acids (SCFA) was higher in AX cultures than in cultures containing FOS and controls, with AX1 presenting the highest concentrations. The stimulatory effect of beneficial bacteria was higher in AX cultures, and AX2 presented the highest positive effect. Prebiotic potential of AX from BSG was confirmed by the production of SCFA and the modulation of gut microbiota, especially by the high increase in bifidobacteria populations.

Distinct actions by Paenibacillus sp. strain E18 α-L-arabinofuranosidases and xylanase in xylan degradation.

We cloned a Paenibacillus sp. strain E18 5.3-kb xylanolytic gene cluster that contains three open reading frames encoding two family 43 α-L-arabinofuranosidases (Abf43A and Abf43B) and one family 10 xylanase (XynBE18). The deduced amino acid sequences of Abf43A and Abf43B were at most 68% and 63% identical to those of two putative family 43 proteins from Clostridium sp. strain DL-VIII (EHI98634.1 and EHI98635.1), respectively, but were only 11% identical to each other. Recombinant Abf43A and Abf43B had similar activities at 45°C and pH 6.0 but varied in thermostabilities and substrate specificities. Abf43B was active against only 4-nitrophenyl α-L-arabinofuranoside, whereas Abf43A acted on 4-nitrophenyl α-L-arabinofuranoside, wheat arabinoxylan, 4-nitrophenyl α-D-xylopyranoside, and sugar beet arabinan. The sequential and combined effects on xylan degradation by XynBE18, Abf43A, and Abf43B were characterized. For beechwood, birchwood, and oat spelt xylans as the substrates, synergistic effects were found when XynBE18 and Abf43A or Abf43B were incubated together and when the substrates were first incubated with Abf43A or Abf43B and then with XynBE18. Further high-performance liquid chromatography (HPLC) analysis showed that the amounts of xylobiose and xylose increased sharply in the aforementioned reactions. For water-soluble wheat arabinoxylan as the substrate, Abf43A not only released arabinose but also had a synergistic effect with XynBE18. Synergy may arise as the result of removal of arabinose residues from xylans by α-L-arabinofuranosidases, which eliminates steric hindrance caused by the arabinose side chains and which allows xylanases to then degrade the xylan backbone, producing short xylooligosaccharides.

Turning hardwood dissolving pulp polysaccharide residual material into barrier packaging.

Birch chips were subjected to pilot-scale pre-hydrolysis under various sets of conditions to mimic a pre-hydrolysis step in a dissolving pulp process. The process generates residual process liquor, a wood hydrolysate, and the treated chips may be directly utilized in a dissolving process. The wood hydrolysates were rich in xylan and utilized in the production of fully renewable films that provide very good oxygen barrier function and mechanical integrity also at high relative humidity. Membrane filtration had an effect in enriching higher molecular weight fractions from the hydrolysates, but noteworthy, a hydrolysate used in the crude state without any membrane filtration performed just as well as upgraded fractions in forming films providing acceptable tensile properties and a good barrier against oxygen permeation.

Understanding pulp delignification by laccase-mediator systems through isolation and characterization of lignin-carbohydrate complexes.

The effects and mechanism of pulp delignification by laccases in the presence of redox mediators have been investigated on unbleached eucalyptus kraft pulp treated with laccases from Pycnoporus cinnabarinus (PcL) and Myceliophthora thermophila (MtL) and 1-hydroxybenzotriazole (HBT) and methyl syringate (MeS) as mediators, respectively. Determination of the corrected κ number in eucalyptus pulps after the enzymatic treatments revealed that the PcL-HBT system exhibited a more remarkable delignification effect than the MtL-MeS system. To obtain further insight, lignin-carbohydrate complexes were fractionated and subsequently characterized by nuclear magnetic resonance, thioacidolysis (followed by gas chromatography and size exclusion chromatography), and pyrolysis-gas chromatography-mass spectrometry (pyrolysis-GC-MS) analyses before and after the enzymatic treatments and their controls. We can conclude that the laccase-mediator treatments altered the lignin structures in such a way that more lignin was recovered in the xylan-lignin fractions, as shown by Klason lignin estimation, with smaller amounts of both syringyl (S) and guaiacyl (G) uncondensed units, as shown by thioacidolysis and gas chromatography, especially after the PcL-HBT treatment. The laccase-mediator treatment produced oxidation at Cα and cleavage of Cα and Cß bonds in pulp lignin, as shown by pyrolysis-GC-MS. The general mechanism of residual lignin degradation in the pulp by laccase-mediator treatments is discussed in light of the results obtained.

Immunolocalization of hemicelluloses in Arabidopsis thaliana stem. Part I: temporal and spatial distribution of xylans.

We investigated the microdistribution of xylans in different cell types of Arabidopsis stem using immunolocalization methods with LM10 and LM11 antibodies. Xylan labeling in xylary fibers (fibers) was initially detected at the cell corner of the S(1) layer and increased gradually during fiber maturation, showing correlation between xylan labeling and general secondary cell wall formation processes in fibers. Metaxylem vessels (vessels) showed earlier development of secondary cell walls than fibers, but revealed almost identical labeling patterns to fibers during maturation. No difference in labeling patterns and intensity was detected in the cell wall of fibers, vessels and protoxylem vessels (proto-vessels) between LM10 and LM11, indicating that vascular bundle cells may be chemically composed of a highly homogeneous xylan type. Interestingly, interfascicular fibers (If-fibers) showed different labeling patterns between the two antibodies and also between different developmental stages. LM10 showed no labeling in primary cell walls and intercellular layers of If-fibers at the S(1) formation stage, but some labeling was detected in middle lamella cell corner regions at the S(2) formation stage. In contrast, LM11 revealed uniform labeling across the If-fiber cell wall during all developmental stages. These results suggest that If-fibers have different xylan deposition processes and patterns from vascular bundle cells. The presence of xylan was also confirmed in parenchyma cells following pectinase treatment. Together our results indicate that there are temporal and spatial differences in xylan labeling between cell types in Arabidopsis stem. Differences in xylan labeling between Arabidopsis stem and poplar are also discussed.

Glucuronoarabinoxylan extracted by treatment with endoxylanase from different zones of growing maize root.

Glucuronoarabinoxylan is a key tethering glucan in the primary cell wall of cereals. Glucuronoarabinoxylan was extracted from different zones of maize (Zea mays L.) roots using endoxylanase that specifically cleaves ß-(1,4)-glycoside bond between two consequent unsubstituted xylose residues. Changes in polysaccharide structure during elongation growth were characterized. Glucuronoarabinoxylan extractable after the endoxylanase treatment consisted of high molecular weight (30-400 kDa) and low molecular weight (<10 kDa) fractions. The presence of high molecular weight derivatives indicated that part of the natural glucuronoarabinoxylan is not digestible by the endoxylanase. This could be due to the revealed peculiar structural features, such as high level of substitution of xylose, absence of unsubstituted xylose residues existing in sequence, and significant degree of acetylation. In maize root meristem the indigestible fraction was 98% of the total extracted glucuronoarabinoxylan. This portion decreases to 47% during elongation. Also, the average molecular weight of indigestible glucuronoarabinoxylan reduced twofold. These changes in the ratio of glucuronoarabinoxylan fragments with different structure during root cell growth could reflect a transition of polysaccharide from its separating (highly substituted indigestible glucuronoarabinoxylan) form to that binding to cellulose microfibrils or other glucuronoarabinoxylan molecules and, hence, retarding growth.

Induction of apoptosis in MCF-7 cells by ß-1,3-xylooligosaccharides prepared from Caulerpa lentillifera.

ß-1,3-Xylan was prepared from the green alga, Caulerpa lentillifera, and hydrolyzed to oligosaccharides by a mild acid treatment. The average degree of polymerization was about 5. The oligosaccharides reduced the number of viable human breast cancer MCF-7 cells in a dose-dependent manner, and induced chromatin condensation and degradation of poly ADP-ribose polymerase, indicating that they induced apoptosis in MCF-7 cells.

Enzymatic cross-linking of alkali extracted arabinoxylans: gel rheological and structural characteristics.

Ferulated arabinoxylans were alkali-extracted from wheat bran at different incubation times (0.0, 0.5, 1.0, 1.5 and 2.0 h). Wheat bran ferulated arabinoxylans (WBAX) arabinose-to-xylose ratio, ferulic acid content, intrinsic viscosity and viscosimetric molecular weight values decreased as the incubation time of extraction increased. WBAX enzymatic cross-linking capability was affected by incubation time while an increase in WBAX concentration from 5 to 6% (w/v) favored gelation. The WBAX gels formed presented a macroporous structure with mesh size ranging from 40 to 119 nm and hardness values varying from 1.7 to 5 N.