Cereal arabinoxylans (AXs) are complex polysaccharides in terms of their pattern of arabinose and ferulic acid substitutions, which influence their properties in structural and nutritional ...applications. We have evaluated the influence of the molecular structure of three AXs from wheat and rye with distinct substitutions on the activity of β-xylanases from different glycosyl hydrolase families (GH 5_34, 8, 10 and 11). The arabinose and ferulic acid substitutions influence the accessibility of the xylanases, resulting in specific profiles of arabinoxylan-oligosaccharides (AXOS). The GH10 xylanase from Aspergillus aculeatus (AcXyn10A) and GH11 from Thermomyces lanuginosus (TlXyn11) showed the highest activity, producing larger amounts of small oligosaccharides in shorter time. The GH8 xylanase from Bacillus sp. (BXyn8) produced linear xylooligosaccharides and was most restricted by arabinose substitution, whereas GH5_34 from Gonapodya prolifera (GpXyn5_34) required arabinose substitution and produced longer (A)XOS substituted on the reducing end. The complementary substrate specificity of BXyn8 and GpXyn5_34 revealed how arabinoses were distributed along the xylan backbones. This study demonstrates that AX source and xylanase specificity influence the production of oligosaccharides with specific structures, which in turn impacts the growth of specific bacteria (Bacteroides ovatus and Bifidobacterium adolescentis) and the production of beneficial metabolites (short-chain fatty acids).
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Arabinoxylans (AX) are the main noncellulose polysaccharide in cereals and grasses. It is a polymer of xylose onto which arabinofuranosyl is substituted. The hydrolysis of AX with AX degrading ...enzymes result in its hydrolysis products called arabinoxylan oligosaccharides (AXOS). Both AX and AXOS are considered as dietary fibers and have been shown to have many health benefits including immunomodulatory activity, cholesterol lowering activity, attenuate type II diabetes, enhanced absorption of certain minerals, fecal bulking effect, and prebiotics effect, etc. With the interest in a healthy diet, dietary fibers such as AX and AXOS are becoming increasingly popular in the food and feed industry. However, compared to the other commonly studied dietary fibers such as fructo-oligosaccharide, AX have not been studied extensively. The purpose of this review is to concise the current research related to AX and its health benefits and thereby encourage in depth studies in this area.
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•Arabinoxylans and arabinoxylan oligosaccharides show prebiotic activity.•They also exhibit immunomodulatory and antitumor activity.•Current research dealing with the health benefits of arabinoxylans is highlighted.
The filterability of barley malt is a critical quality parameter in beer brewing. The effects of two mashing processes (processes A and B) on the filterability of the three barley malts and their ...macromolecule contents were investigated. Filtration volume increased by 4%, 9%, and 13% for the Baudin, Ganpi, and Gangpi malts, respectively, and the final filtration volume of Gangpi was still poorer than that of Baudin. A downward mashing process (process C) was applied to measure the β‐glucan, arabinoxylans (AX), the polymeric arabinoxylan (PAX), and high molecular weight nitrogen (HMWN) content. The β‐glucan degradation rate of well‐modified malt during malting was higher than that of poorly modified malt, whereas the PAX and HMWN solubilization rates during malting were lower in well‐modified malt than in poorly modified malt. The filterability of poorly modified malt did not effectively improve with an initial mashing phase at 37℃. β‐Glucan degradation and PAX and HMWN solubilization during malting were critical for ensuring malt quality. Thus, the goal of predicting the filterability of malt was achieved by applying a downward mashing process.
Practical Application
Quality of wort and beer as well as production efficiency is affected by the malt quality. The filterability of barley malt can affect the production efficiency and quality of wort. The change in the macromolecule contents during malting is important to ensure the production of high‐quality malt. The results of this study can provide a good method for the detection of malt filtration performance, and it also may contribute to the purpose of prediction the changes in barley malt and the resulting barley malt filterability.
While arabinoxylans (AX), an important dietary fiber fraction of wheat-based broiler diets, are known for exerting antinutritional effects in the gastrointestinal (GI) tract of broilers, the ...prebiotic potential of arabinoxylan-oligosaccharides (AXOS) is also well-documented. However, inconsistent performance responses as well as the effectiveness of low amounts of AXOS used in diets of previously conducted experiments put into question the classical prebiotic route being the sole mode of action of AXOS. The objective of this study was to investigate the effects of dietary AXOS addition on the rate of AX digestion in the gastrointestinal tract of broilers as a function of broiler age to gain more insight into the mode of action of these oligosaccharides. A feeding trial was performed on 480 one-day-old chicks (Ross 308) receiving a wheat-based diet supplemented with or without 0.50% AXOS, containing no endoxylanases. Digesta samples from ileum and caeca and fecal samples were analyzed for AX content, AX digestibility, intestinal viscosity, and microbial AX-degrading enzyme activities at 6 different ages (day 5, 10, 15, 21, 28, 35). Chicks fed from hatching with 0.50% AXOS demonstrated a higher ileal viscosity (P < 0.05). Also higher levels of AX solubilization and fermentation compared to control birds at 10 D were observed. This was noted by the higher total tract AX digestibility of water-extractable AX (WE-AX) and total AX (TOT-AX) at this age (P < 0.05). Although no significant difference in AX-degrading enzyme activities was observed among the dietary treatments, AXOS supplementation in young broilers was shown to stimulate or “kick-start” dietary AX digestion, thereby speeding up the development of a fiber-fermenting microbiome in the young broiler. This stimulation effect of AXOS could enable greater functional value to be extracted from dietary fiber in broiler feeds.
•Isolated rye starch, protein and modified arabinoxylans were used for model baking.•Cross-linked and hydrolyzed AXs were characterized and applied in baking.•Composed model mix ensured proper ...characteristics of rye dough and bread.•The maximum applicable level of poorly soluble cross-linked AX was 3%.•Highly soluble, hydrolyzed AX could be used at 6%.
The role of water extractable arabinoxylan with varying molar mass and structure (cross-linked vs. hydrolyzed) in the structure formation of rye bread was examined using a model bread. Instead of the normal flour, the dough contained starch, arabinoxylan and protein, which were isolated from rye wholemeal. It was observed that the applied mixes of these constituents result in a product closely resembling typical rye bread, even if arabinoxylan was modified (by cross-linking or hydrolysis).
The levels of arabinoxylan required for bread preparation depended on its modification and mix composition. At 3% protein, the maximum applicable level of poorly soluble cross-linked arabinoxylan was 3%, as higher amounts of this preparation resulted in an extensively viscous dough and diminished bread volume. On the other hand highly soluble, hydrolyzed arabinoxylan could be used at a higher level (6%) together with larger amounts of rye protein (3% or 6%). Further addition of arabinoxylan leads to excessive water absorption, resulting in a decreased viscosity of the dough during baking and insufficient gas retention.
The study evaluated the yield, emulsifying, antioxidant properties, protein content and amino acid composition of water-extractable (WE) and alkali-extractable (AE) Hemi-B and the water holding ...capacity and protein content of cellulose-rich arabinoxylan (CAX) fractions isolated from the bran of four wheat varieties. It was observed that CAX from the variety C-306 possessed the lowest protein content (3.83%) and the highest water holding capacity (16.13%). Total phenolic content of AE-Hemi-B and WE-Hemi-B fractions varied from 4.54 to 7.47 mg ferulic acid equivalents (FAE)/g and 3.51–4.91 mg FAE/g, respectively. Except for the AE-Hemi-B fraction of HS-490, bound phenolic content was higher than free phenolic content. AE-Hemi-B had exceptionally higher bound phenolic and antioxidant content. FTIR bands at 1364 cm−1, 1028 cm−1 and 849 cm−1confirmed the presence of a highly branched arabinoxylan structure. The presence of phenolic ring structure, characteristic of ferulic acid, was confirmed by the band signal at 1520 cm−1. The emulsion stability of WE-Hemi-B decreased drastically, after storage at accelerated temperature (60 °C). However, all AE-Hemi-B yielded good emulsions, expect HD-2967 variety, which exhibited the poorest emulsion stability, while, C-306 yielded exceptionally stable emulsion, better than well-known corn fiber gum, up to 3 days under accelerated storage.
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•AE-Hemi-B fractions had higher TPC than WE-Hemi-B fractions.•Antioxidant activity was high for bound extracts prepared by alkali hydrolysis.•CAX from C-306 wheat variety had the highest water holding capacity.•WE-Hemi-B had poor emulsion stability.•AE-Hemi-B fraction from C-306 exhibited a good ability to form stable emulsions.
•Water-extractable arabinoxylan increased you-tiao’s specific volume and oil content.•Water-extractable arabinoxylan inhibited the thermal aggregation of gluten proteins.•Water-unextractable ...arabinoxylan hindered the expansion of the gluten network.•Water-extractable arabinoxylan reduced the contents of β-sheet and the random coil.•Water-extractable arabinoxylan improved the quality of whole-wheat youtiao.
This research aimed to investigate the effects of water-extractable arabinoxylan (WEAX) and water-unextractable arabinoxylan (WUAX) on the quality of you-tiao. In this work, the interactions between different amounts of AX and wheat gluten were extensively evaluated during frying treatment. The results showed that WEAX impaired the surface hydrophobicity of gluten and improved its solubility, while WUAX had the opposite effect. The fluorescence spectra revealed that WEAX and WUAX changed the conformation of gluten molecules. Besides, chemical interaction measurement indicated that WEAX and WUAX prevented the formation of partial disulfide bonds and inhibited the thermal aggregation of gluten proteins. In summary, the results indicated that WEAX partly improved the properties of you-tiao. Meanwhile, WUAX reduced the dough's oil content and specific volume, resulting in you-tiao with poor quality.
This work demonstrates that sesame (Sesamum indicum L.) hull, an unexploited food industrial waste, can be used as an efficient source for the extraction of hemicellulose and/or pectin ...polysaccharides to further obtain functional oligosaccharides. Different polysaccharides extraction methods were surveyed including alkaline and several enzymatic treatments. Based on the enzymatic release of xylose, arabinose, glucose, and galacturonic acid from sesame hull by using different enzymes, Celluclast®1.5 L, Pectinex®Ultra SP-L, and a combination of them were selected for the enzymatic extraction of polysaccharides at 50 °C, pH 5 up to 24 h. Once the polysaccharides were extracted, Ultraflo®L was selected to produce arabinoxylo-oligosaccharides (AXOS) at 40 °C up to 24 h. Apart from oligosaccharides production from extracted polysaccharides, alternative approaches for obtaining oligosaccharides were also explored. These were based on the analysis of the supernatants resulting from the polysaccharide extraction, alongside a sequential hydrolysis performed with Celluclast®1.5 L and Ultraflo®L of the starting raw sesame hull. The different fractions obtained were comprehensively characterized by determining low molecular weight carbohydrates and monomeric compositions, average Mw and dispersity, and oligosaccharide structure by MALDI-TOF-MS. The results indicated that sesame hull can be a useful source for polysaccharides extraction (pectin and hemicellulose) and derived oligosaccharides, especially AXOS.
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•Peroxidase catalyzes the crosslinking of soymilk proteins and arabinoxylan.•Crosslinking promotes unfolding, recombination of soymilk protein and decreases H0.•Soymilk ...protein-arabinoxylan conjugates exhibit better gel properties.
Arabinoxylan (AX) can form stable covalent bonds with protein to improve gel properties. We aimed to prepare a conjugate between soymilk protein (SMP) and AX by peroxidase, followed by the addition of transglutaminase (TG) to prepare tofu gels. The conjugate’s properties and their effects on the mechanical properties, rheological properties, and microstructure of tofu gels were evaluated. Results revealed that the α-helix content decreased, the β-sheet content increased, and the surface hydrophobicity reduced from 1.60 × 105 to 1.27 × 105. The optimal amount of AX required to improve the properties of tofu gel was 1.0%. The tofu gel showed better hardness (118.44 g), water holding capacity (WHC) (86.17%), and higher storage modulus (G′) and loss modulus (G″). Low-Field NMR (LF-NMR) showed that the water was evenly distributed. Scanning electron microscopy (SEM) revealed a denser and more regular three-dimensional gel network.
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