Isolation of Hemicellulose from Corn Fiber by Alkaline Hydrogen Peroxide Extraction

For the first time, alkaline hydrogen peroxide (AHP) extraction conditions were used to isolate hemicellulose (arabinoxylan) from destarched corn fiber. Yields of the water-soluble hemicellulose B ranged from 35% (24 hr extraction at 25°C) to 42% (2 hr extraction at 60°C). The hemicellulose B resulting from the 2 hr extraction (pH 11.5) was off-white in color, and a very low proportion (1.7%) of water-insoluble hemicellulose A was extracted. AHP treatment caused delignification and facilitated the alkaline extraction of hemicellulose from the lignocellulosic fiber matrix. In the absence of H₂O₂, yields were reduced by more than one-third when using otherwise identical extraction conditions of time, temperature and pH. In the standard protocol, corn fiber, NaOH solution, and H₂O₂ were mixed in a 1:25:0.25 (w/v/w) ratio. Extractions were conducted at pH 11.5 at 25°C or 60°C. The pH was adjusted to 11.5 by addition of NaOH at ambient and elevated temperatures. The optimum hemicellulose yield (51.3%; dry, starch-free basis) was obtained when the pH was increased to 12.5 for the final one-half of the extraction period. Products obtained after extraction at pH values greater than 11.5 were tan in color, however, and the goal of the research has been to isolate white hemicellulose B and then evaluate its properties. Under most conditions, the yields ofhemicellulose B, potentially the most useful form for food and industrial applications, exceeded those of hemicellulose A by more than 10-fold. The hemicellulose B products were lighter in color than those obtained using traditional alkaline extraction conditions of refluxing with calcium or sodium hydroxide. Steps prior to extractions with alkaline H₂O₂, such as grinding to 20 mesh and extracting with azeotropic toluene-ethanol, were found to be unnecessary.     

An Improved Process for Isolation of Corn Fiber Gum

Sequential alkaline extraction and alkaline hydrogen peroxide (AHP) bleaching have been used to prepare corn fiber gum in yields ranging from 21 to 40%, depending on the pH of the extraction medium. The pH was adjusted by using different ratios of NaOH and Ca(OH)₂ The whitest product was obtained after AHP bleaching of the extract obtained using the lowest pH value. In order for the product gum to give its characteristic clear and low viscosity solutions, it was necessary to remove starch from the corn fiber substrate using α-amylase. The water-insoluble hemicellulose A fraction, a minor component, was removed by neutralizing AHP-treated extracts before ethanol precipitation of the useful hemicellulose B (corn fiber gum) fraction. At ambient temperature, AHP bleaching was near optimal after ≈2 hr under the processing conditions used. High ratios of arabinose (39%) to xylose (50%) were present in the corn fiber gum extracted under various alkaline conditions, and the H₂O₂ processing step did not significantly alter these ratios. The same low levels of galactose (7%) and glucuronic acid (4%) were present regardless of the extraction conditions. Molecular mass of the corn fiber gum preparations ranged from 2.78 × 10⁵ for the material extracted with Ca(OH)₂ to 3.94 × 10⁵ for the material extracted with NaOH. Molecular mass was unaffected by the H₂O₂ present in the second processing step. As expected for a carbohydrate polymer with a rather low uronic acid content, solution viscosities were unaffected by the presence of salt.     

Molecular Characteristics of Corn Fiber Gum and Their Influence on CFG Emulsifying Properties

The molecular characteristics of two purified arabinoxylan fractions derived from corn kernels, corn fiber gum-1 and -2 (CFG-1 and -2), have been studied and correlated with emulsifying properties. CFG-1 and -2 fractions were isolated from different corn fiber sources by 1) a sequential alkaline extraction and H₂O₂ bleaching to produce CFG-1; and 2) additional H₂O₂ treatment of the alkali-extracted residue at pH 11.5, yielding CFG-2. Multiangle laser light-scattering and online viscosity were used to measure the molar mass, polydispersity, structure compactness, and intrinsic viscosity of the generated CFG fractions. Emulsification properties in an oil-in-water emulsion system with 10:1 oil-to-gum ratio was investigated by measuring turbidity of an aliquot from the bottom of the diluted emulsion over 10 days. The isolated CFG-2 from each fiber source was higher in weight-average molar mass (M_w) polydispersity) (M_w/M_n) and structure compactness, and also lower in solution weight-average intrinsic viscosity (η_w) than the corresponding CFG-1. Average M_w and η_w values were 244–491 kDa and 1.35–1.84 dL/g, respectively. The emulsion stabilizing capacity of CFG-2 from each fiber source was superior to the corresponding CFG-1.     

Recovery of Fiber in the Corn Dry-Grind Ethanol Process: A Feedstock for Valuable Coproducts

A new process was developed to recover corn fiber from the mash before fermentation in dry-grind ethanol production. In this process, corn is soaked in water (no chemicals) for a short period of time and then degermed using conventional degermination mills. In the remaining slurry, corn coarse fiber is floated by increasing the density of the slurry and then separated using density differences. The fiber recovered is called quick fiber to distinguish it from the conventional wet-milled fiber. This study evaluated the percent of quick fiber recovery for a normal yellow dent and high oil corn hybrid. The quick fiber was analyzed for levels of corn fiber oil, levels of ferulate phytosterol esters (FPE) and other valuable phytosterol components in the oil and compared with conventional wet-milled corn coarse and fine fiber samples. Fiber samples were also analyzed and compared for yields of potentially valuable corn fiber gum (CFG, hemicellulose B). Comparisons were made between the quick fiber samples obtained with and without chemicals in the soakwater. An average quick fiber yield of 6–7% was recovered from the two hybrids and represented 46–60% of the total fiber (fine and coarse) that could be recovered by wet-milling these hybrids. Adding steep chemicals (SO₂ and lactic acid) to the soakwater increased the quick fiber yields, percent of FPE recoveries, and total percent of phytosterol components to levels either comparable to (for the dent corn hybrid) or higher than (for the high oil corn hybrid) those recovered from the total conventional wet-milled fiber samples. CFG yields in the quick fiber samples were comparable to those from the wet-milled fiber samples. CFG yields in the quick fiber samples were not significantly affected by the addition of chemicals (SO₂ and lactic acid) to the soakwater.     

Phenolic acids, lipids, and proteins associated with purified corn fiber arabinoxylans

Corn fiber gum (CFG) is a hemicellulose (arabinoxylan)-enriched fraction obtained by the extraction of corn bran/fiber using a proprietary alkaline hydrogen peroxide process. When purified CFG prepared by this process was hydrolyzed with more concentrated base (1.5 N methanolic KOH at 70 degrees C for 1 hour), considerable amounts of hydroxycinnamic acids (up to 0.015% of mainly ferulic acid) and lipids (up to 0.43%) were released. The released phenolic acids and lipids were identified and quantified using high-performance liquid chromatography (HPLC) with detection by both UV and evaporative light-scattering detection (ELSD). During the wet milling of corn, two types of corn fiber are produced: coarse fiber, which is primarily from pericarp, and fine fiber, which is from the endosperm. The total phenolic acid content in CFGs purified from coarse corn fiber (pericarp fiber) is comparatively higher than that purified from fine corn fiber (endosperm fiber). It was also determined that the purified CFG samples contained significant amounts of strongly associated proteins, from 2 to 5% by weight. The presence of these phenolic acids, lipids, and proteins strongly associated or bound to CFG may contribute to its excellent ability to emulsify oil-in-water emulsions.     

Importance of Protein‐Rich Components in Emulsifying Properties of Corn Fiber Gum

Purified corn fiber gum (CFG‐F) isolated from fine (kernel endosperm‐derived) corn fiber that contained ≈2% residual protein was extracted with 70% aqueous ethanol. The aqueous ethanol extract (AEE), which contained 19.5% of the total CFG, contained a high percentage of the proteinaceous material present in the original gum sample. The AEE gum contained 6.81% protein by weight. The residue (R), which constituted 66% of the total CFG‐F, contained only 0.55% of protein. The emulsifying properties of R and AEE in a model oil‐in‐water emulsification system were studied by measuring turbidity after 1, 2, and 3 weeks, particle size after 4 weeks, and by confocal laser scanning microscopy after three months of storage at room temperature. These gums were compared with the standard well‐known emulsifiers native acacia gum (NAG) and modified acacia gum (MAG). The results indicate that although AEE contains protein‐rich components, it is not as good an emulsifier as the residue which contains only 0.55% of protein. However, emulsions prepared with the whole (unfractionated) CFG‐F under similar conditions were more stable showing higher turbidity and smaller particles size than those prepared with either R or AEE.     

Analysis and properties of arabinoxylans from discrete corn wet-milling fiber fractions

Three fibrous corn wet-milling fractions, coarse fiber, fine fiber, and spent flake, were isolated. More highly valued uses are sought for these milling products, which are generally directed into the corn gluten feed product stream. Coarse fiber was further dissected into pericarp and aleurone layers. An alkaline hydrogen peroxide process was used to efficiently extract corn fiber gum (CFG) from each of the materials. CFG is a hemicellulose B arabinoxylan which also contains low levels of D,L-galactose and D-glucuronic acid. CFG yield information was obtained from each source, as well as structural information in terms of degrees of branching of the beta-D-xylopyranose backbone with alpha-L-arabinofuranosyl moieties. There were significant differences in degree of branching among the CFGs from the various fractions. A novel capillary electrophoresis procedure was developed to measure these differences. Solution viscosity differences among the CFGs were also observed.     

Effect of Alternative Milling Techniques on the Yield and Composition of Corn Germ Oil and Corn Fiber Oil

The effects of alternative corn wet‐milling (intermittent milling and dynamic steeping (IMDS), gaseous SO₂ and alkali wet‐milling) and dry grind ethanol (quick germ and quick fiber with chemicals) production technologies were evaluated on the yield and phytosterol composition (ferulate phytosterol esters, free phytosterols, and fatty acyl phytosterol esters) of corn germ and fiber oil and compared with the conventional wet‐milling process. Small but statistically significant effects were observed on the yield and composition of corn germ and fiber oil with these alternative milling technologies. The results showed that the germ and fiber fractions from two of the alternative wet‐milling technologies (the gaseous SO₂ and the IMDS) had, for almost all of the individual phytosterol compounds, either comparable or signficantly higher yields compared with the conventional wet‐milling process. Also, both of the modified dry grind ethanol processes (the quick germ and quick fiber) with chemicals (SO₂ and lactic acid) can be used as a new source of corn germ and fiber and can produce oils with high yields of phytosterols. The alkali wet‐milling process showed significantly lower yields of phytosterols compounds in germ but showed significantly higher yield of free phytosterols, fatty acyl phytosterol esters and total phytosterols in the fiber fraction.     

Isolation, purification, and identification of protein associated with corn fiber gum

Corn fiber gum (CFG), an alkaline hydrogen peroxide extract of the corn kernel milling byproduct "corn fiber", is a proteinaceous arabinoxylan with protein content ranging from ca. 2 to 9% by weight for CFG samples isolated from different corn milling fiber sources. Several studies have suggested that protein associated with CFG could be partly responsible for its excellent emulsifying properties in oil-in-water emulsion systems. Nevertheless, the composition and identity of the protein component has never been determined. In the present study, CFG was deglycosylated by treating with trifluoromethanesulfonic acid, and the resulting proteins were purified by passage through C18 solid phase extraction cartridges. The proteins were then separated and characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The protein band from the gel was treated with a proteolytic enzyme, chymotrypsin, and the resulting peptides were cleaned using C18 Zip Tip pipet tips and analyzed using matrix-assisted laser desorption/ionization with automated tandem time-of-flight mass spectrometry. The partial sequences derived from the mass spectrometry analyses of the resulting chymotryptic peptides were found to be similar to the 22-kDa alpha-zein Z1 (az22z1) protein (a major storage protein in corn endosperm) when queried against the primary sequences from the National Center for Biotechnology Information database. This is the first report that this hydrophobic protein is associated with CFG and may explain why CFG is an excellent emulsifier for oil-in-water emulsion systems.     

Effect of Various Acids and Sulfites in Steep Solution on Yields and Composition of Corn Fiber and Corn Fiber Oil

The addition of six acids (organic and inorganic) and four sulfite compounds (including gaseous SO₂) during the conventional corn wet‐milling steeping process of two yellow dent corn hybrids were evaluated for the effect on corn fiber yield, corn fiber oil yield, and the composition of three phytosterol compounds (ferulate phytosterol esters [FPE], free phytosterols [St], and phytosterol fatty acyl esters [St:E]) in the corn fiber oil. No significant effect of different sulfite compounds and acids were observed on corn fiber yields. However, a significant effect was observed on corn fiber oil yield and the composition of corn fiber oil for phytosterol compounds. Three of the sulfite compounds (including gaseous SO₂) caused very little effect on the levels of phytosterol compounds compared with the control sample (corn steeped with sodium metabisulfite and lactic acid). However, for one hybrid, ammonium sulfite gave a significantly higher yield of FPE and St:E and had no effect on the yield of St. For the other hybrid, it gave a significantly higher yield of FPE and had no effect on the yield of St and St:E compared with the control sample. This indicates that the effect of these sulfite compounds on yields of these phytosterol compounds in corn fiber oil is probably hybrid‐dependent. No significant effect of acids was observed on corn fiber yields, but significant effects were observed on corn fiber oil yields and yields of phytosterol compounds in the corn fiber oil. The effect also seems to be hybrid‐dependent because different acids affected the two hybrids differently. Overall, it seems that weak acids have a positive effect on increasing the individual phytosterol compounds in the corn fiber. When comparing the effect of experimental acids and sulfites on the two hybrids, acids have a more positive effect than sulfites in increasing the yield of phytosterol compounds in corn fiber oil.     

Response of corn to plowed‐down and disked‐in Zn as zinc sulfate

Abstract

A field investigation was conducted to compare the efficacy of plowed‐down and disked‐in Zn as ZnSO₄.H₂O in correcting Zn deficiency of corn (Zea mays L.). The soil, Buchanan fine sandy loam, was nearneutral in pH and contained 0.7 ppm of EDTA‐extractable Zn and 1.4 ppm of dilute HCl‐H₂SO₄ extractable P. Application of 6.72 kg Zn/ha as ZnSO₄.H₂O corrected Zn deficiency of corn plants on the soil. Corn grain yields and Zn concentrations in tissue samples indicated that the plowed‐down and disked‐in Zn were about equally effective in correcting Zn deficiency where the level of Zn application was 6.72 kg/ha.     

Effects of Arabinoxylans on Activation of Murine Macrophages and Growth Performance of Broiler Chicks

Arabinoxylans occur in a wide variety of agricultural products and may contribute a significant portion of human dietary fiber intake. Corn hulls and banana peels are potential sources of arabinoxylans with isolation yields of ≈40 and 10% when extracted with dilute alkali. A broiler chick growth study was performed to determine the effect of extracted corn hull arabinoxylan on performance and attachment of Salmonella, as a representative of an enteric pathogen, to the ileum. Ability of arabinoxylans to activate a macrophage cell line as an immune stimulator was determined by respiratory burst assay. Corn hull arabinoxylan tended to increase body weight gain and reduced attachment of Salmonella to ileal tissue in broiler chicks undergoing mild heat stress. Arabinoxylans from corn hulls and banana peels showed positive oxidative burst in macrophage cells. Collectively, these data indicate the two arabinoxylans have the potential to be used as health‐promoting dietary supplements.     

Structural characterization of corn fiber gums from coarse and fine fiber and a study of their emulsifying properties

The stabilities of orange oil emulsions stabilized with various concentrations of two different types of corn fiber gum (CFG-1 and 2) isolated from coarse (pericarp) and fine (endosperm) fiber from corn wet milling have been studied. The emulsion stabilities in all these studies increased with increasing gum concentration up to a gum-to-oil ratio of 0.05, and after that it either levels off or changes very slightly. These results indicate that only 0.25% of CFG is required to make stable emulsion containing 5% orange oil under the experimental conditions used in this study. At this CFG concentration, CFG-2 from each fiber source was found to be a superior emulsifier relative to the corresponding CFG-1 from each source in a 10-day emulsion stability study at room temperature. The emulsion stability was also investigated by confocal laser scanning microscopy measurement, and it was found that CFG-1 and 2 from both coarse and fine fiber made stable emulsions with an average particle size of less than 1 mum for 10 days at room temperature. Sugar composition analysis of CFGs from both sources indicated that they were typical galactoglucuronoarabinoxylans containing mainly 55-59% xylose, 29-36% arabinose, and 4-6% galactose as neutral sugars and 3-5% glucuronic acid. Methylation analysis revealed a highly branched structure of all CFGs, in which only 16-25% of the 1--> 4-linked xylose residues were not substituted at O-2 and/or O-3. Arabinose is present both as a terminal residue and at branch points.     

Evaluation of the fertilizer value and nutrient release from corn and soybean residues under laboratory and greenhouse conditions

Abstract

Laboratory and greenhouse studies were conducted on a moderately fertile Taloka (fine, mixed, thermic mollic Albaqualf) silt loam and a low fertility Leadvale (fine‐silty, siliceous, thermic typic Fragiudult) silt loam to evaluate nutrient release and fertilizer value of soybean [Glycine max (L.) Herr.] and corn (Zea mays L.) residues as compared to the inorganic fertilizer 13–13–13–13 (N‐P₂O₅‐K₂O‐S). Residues and the inorganic fertilizer were applied at 50 mg N/kg in a incubation study and at 25 and 50 mg N/kg in a greenhouse study. The incubation study indicted that carbon dioxide (CO₂) evolution and nitrogen (N) mineralization followed a identical sequence: soybean > corn residues, similar to residue N concentration and carbon/nitrogen (C/N) ratio sequence. Application of corn residues produced N immobilization in both soils (‐20 mg N/kg soil), whereas soybean increased inorganic soil N in the Leadvale soil (3 mg N/kg soil) and particularly in the Taloka soil (17 mg N/kg soil). The greenhouse study showed the superiority of the inorganic fertilizer over corn and soybean residues for sorghum‐sudan yield, and N, phosphorus (P), potassium (K), and sulfur (S) total uptake. No significant differences were found among the residues and between residues and the control with the exception of the higher soybean rate for total N uptake in the Taloka soil, and the higher corn and soybean residue rate in the Leadvale soil for total K uptake. It also appeared that soybean residues provided a substantial amount of N and S to sorghum‐sudan. Higher rates of both soybean and corn residues constituted a prime source of K, particularly in the Landvale soil which had a low exchangeable soil K level.     

Oxygen and redox potential gradients in the rhizosphere of alfalfa grown on a loamy soil

Oxygen (O₂) supply and the related redox potential (E_H) are important parameters for interactions between roots and microorganisms in the rhizosphere. Rhizosphere extension in terms of the spatial distribution of O₂ concentration and E_H is poorly documented under aerobic soil conditions. We investigated how far O₂ consumption of roots and microorganisms in the rhizosphere is replenished by O₂ diffusion as a function of water/air‐filled porosity. Oxygen concentration and E_H in the rhizosphere were monitored at a mm‐scale by means of electroreductive Clark‐type sensors and miniaturized E_H electrodes under various matric potential ranges. Respiratory activity of roots and microorganisms was calculated from O₂ profiles and diffusion coefficients. pH profiles were determined in thin soil layers sliced near the root surface. Gradients of O₂ concentration and the extent of anoxic zones depended on the respiratory activity near the root surface. Matric potential, reflecting air‐filled porosity, was found to be the most important factor affecting O₂ transport in the rhizosphere. Under water‐saturated conditions and near field capacity up to –200 hPa, O₂ transport was limited, causing a decline in oxygen partial pressures (pO₂) to values between 0 and 3 kPa at the root surface. Aerobic respiration increased by a factor of 100 when comparing the saturated with the driest status. At an air‐filled porosity of 9% to 12%, diffusion of O₂ increased considerably. This was confirmed by E_H around 300 mV under aerated conditions, while E_H decreased to 100 mV on the root surface under near water‐saturated conditions. Gradients of pO₂ and pH from the root surface indicated an extent of the rhizosphere effect of 10–20 mm. In contrast, E_H gradients were observed from 0 to 2 mm from the root surface. We conclude that the rhizosphere extent differs for various parameters (pH, Eh, pO₂) and is strongly dependent on soil moisture.     

Enzymatic Milling Product Yield Comparison with Reduced Levels of Bromelain and Varying Levels of Sulfur Dioxide

Enzymatic milling (E‐Milling) is a process that could potentially replace the sulfur dioxide procedure currently used in all commercial wet‐milling facilities. E‐Milling incorporates the use of a short water soaking step (≤6 hr), a coarse grind, and the use of a protease to release the starch granules from the corn endosperm. E‐Milling does not require sulfur dioxide to obtain starch yields equivalent to conventional wet milling; however, the important antimicrobial effects of sulfur dioxide are not duplicated by the enzymatic process. The use of low levels of sulfur dioxide (sufficient for antimicrobial activity) is being proposed as an easily implemented means of microbial control during E‐Milling. To assess the effectiveness of E‐Milling under these conditions, fraction yields for milling experiments adding sulfur dioxide with and without added enzyme were compared with fraction yields from conventional 24‐hr steeping with 2,000 ppm SO₂ and 0.55% lactic acid. Because adding enzyme and SO₂ can both improve product yields and compositions independently, it was necessary to use a reduced level of enzyme (much less than necessary to generate “product quality” material) to observe differences in terms of product yields. The results show significant differences in starch, fiber, total gluten, and insoluble gluten recoveries between samples milled with SO₂ and enzyme compared with those at the same SO₂ level without enzyme addition. No significant differences were observed for soakwater or germ yields regardless of the SO₂ level used. The yield benefits from adding both enzyme and SO₂ are clearly shown over the addition of each individually, for all coproduct yields with the exception of the yields for germ.     

Preparation and Properties of Oxidized Corn Starches by Semi-Dry Process

Oxidized corn starch prepared by a semi-dry process using hydrogen peroxide as an oxidant was studied. The optimum oxidation conditions of corn starch were mole ratio of H₂O₂ and anhydroglucose unit (0.219); mole ratio of NaOH and anhydroglucose unit (0.144); moisture content of the reaction mixture (27.2%); and reaction temperature (65°C). Compared with oxidized corn starch produced by reacting starch with sodium hypochlorite in alkaline slurry, oxidized corn starches produced by a semi-dry process apparently had different properties. Oxidation by a semi-dry process for corn starch resulted in significant changes in the degree of crystallinity of starch and the changes increased with the increase of carboxyl content of starch. Peak viscosities of oxidized starches produced by a semi-dry process were lower than those of commercial corn starch at similar carboxyl contents, while the final viscosities and setbacks of the former were much higher than the latter. There were apparent differences for texture properties among oxidized starches prepared by different processes. Onset temperature, peak temperature, and conclusion temperature of semi-dry oxidation starches were higher than those of commercial oxidized starch, while the enthalpy of gelatinization of the former were lower than the latter.     

Availability and extractability of soil manganese in a liming experiment

Abstract

The availability of soil Mn to corn in relation to extractability of soil Mn by EDTA, Mg(NO₃)₂, CH₃COONH₄, hydroquinone, H₃PO₄, and NH₄H₂PO₄ as affected by liming was evaluated under field conditions on a single soil type. EDTA, Mg(NO₃)₂ and CH₃COONH₄‐extractable Mn were related inversely to available Mn. No useful relationships were found between hydroquinone, H₃PO₄, and NH₄H₂PO₄‐extractable soil Mn and Mn uptake by sweet corn.     

Isolation and Characterization of Water‐Extractable Arabinoxylan from Hull‐less Barley Flours

A new procedure was developed for the isolation of highly purified water‐extractable arabinoxylan (WE‐AX) from hull‐less barley flour. It included inactivation of endogenous enzymes, removal of proteins with silica gel, and removing β‐glucans, arabinogalactan‐peptides, and starch fragments by enzyme or solvent precipitation steps. WE‐AX recovered by this isolation procedure represented, on average, 47% of all WE‐AX present in hull‐less barley flour. Purified WE‐AX from flour of different hull‐less European barley cultivars contained 84.9–91.8% AX and showed small structural differences. The apparent peak molecular weight of the purified WE‐AX was 730,000–250,000, and the arabinose‐to‐xylose ratio was 0.55–0.63. Proton nuclear magnetic resonance spectroscopy showed that the levels of un‐, O‐2 mono‐, O‐3 mono‐, and O‐2,O‐3 disubstituted xylose residues were 59.1–64.7%, 8.2–10.0%, 5.7–10.6%, and 17.6– 23.1%, respectively, and the ratio of di‐ to monosubstituted xylose was 0.90–1.54. Both O‐3 mono‐ and disubstituted xylose residues occurred isolated or next to disubstituted xylose residues in the WE‐AX chain.     

Structural Characteristics of Water‐Extractable Nonstarch Polysaccharides from Barley Malt

Water‐extractable (WE) material was isolated from a Canadian barley malt (cv. Harrington). The purified WE material contained mainly arabinoxylans, β‐glucans, proteins, and small amounts of arabinogalactans and mannose‐containing polymers. WE material was treated with specific enzymes to obtain two fractions: one enriched in arabinoxylan (AX) and another enriched in β‐glucan (BG). The AX fraction was further fractionated by stepwise precipitation in (NH₄)₂SO₄ into five arabinoxylan subfractions. ¹H‐NMR spectroscopy and sugar analyses revealed a relatively high content of unsubstituted xylose residues (48–58%) as well as a relatively high content of doubly substituted xylose residues (28–33%) in the structure of the arabinoxylans. β‐Glucans constituted a minor portion of water‐extractable malt polysaccharides and were characterized by high levels of tri‐ and tetrasaccharide residues (93.4%) with a molar ratio of 2.19 for cellotriosyl to cellotetraosyl units. Size‐exclusion chromatography revealed that the WE material contained several polymer populations. One population had a very high molecular weight that appeared to be the result of aggregation. The AX fraction contained higher molecular weight polymers than the BG fraction.