| 1. |
- Berger, Karin, et al.
(författare)
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Cereal Byproducts Have Prebiotic Potential in Mice Fed a High-Fat Diet
- 2014
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 62:32, s. 8169-8178
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Tidskriftsartikel (refereegranskat)abstract
- Barley husks, rye bran, and a fiber residue from oat milk production were processed by heat pretreatment, various separation steps, and treatment with an endoxylanase in order to improve the prebiotic potential of these cereal byproducts. Metabolic functions were intended to improve along with improved microbial activity. The products obtained were included in a high-fat mouse diet so that all diets contained 5% dietary fiber. In addition, high-fat and low-fat controls as well as partially hydrolyzed guar gum were included in the study. The soluble fiber product obtained from rye bran caused a significant increase in the bifidobacteria (log copies of 16S rRNA genes; median (25−75 percentile): 6.38 (6.04−6.66) and 7.47 (7.30−7.74), respectively; p < 0.001) in parallel with a tendency of increased production of propionic acid and indications of improved metabolic function compared with high-fat fed control mice. The oat-derived product caused an increase in the pool of cecal propionic (from 0.62 ± 0.12 to 0.94 ± 0.08) and butyric acid (from 0.38 ± 0.04 to 0.60 ± 0.04) compared with the high-fat control, and it caused a significant increase in lactobacilli (log copies of 16S rRNA genes; median (25−75 percentile): 6.83 (6.65−7.53) and 8.04 (7.86−8.33), respectively; p < 0.01) in the cecal mucosa. However, no changes in measured metabolic parameters were observed by either oat or barley products.
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| 2. |
- Falck, Peter, et al.
(författare)
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Production of arabinoxylan-oligosaccharide mixtures of varying composition from rye bran by combination of process conditions and type of xylanase.
- 2014
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Ingår i: Bioresource Technology. - : Elsevier BV. - 1873-2976 .- 0960-8524. ; 174, s. 118-125
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Tidskriftsartikel (refereegranskat)abstract
- The aim was to study arabinoxylan-oligosaccharide production from rye bran using heat pretreatment and enzymatic hydrolysis. Due to the potential application in foods, the purity of arabinoxylan was also assessed. Rye bran was heat pretreated to improve xylanase-catalyzed hydrolysis of arabinoxylan into arabinoxylan-oligosaccharides. Enzymatic removal of starch and proteins before or after heat pretreatment increased the purity, although at lower yield. The most attractive process resulted in 62% (w/w) arabinoxylan content after ethanol precipitation. Using xylanases from two glycoside hydrolase families (RmXyn10A from GH10 and Pentopan Mono BG from GH11), different mixtures of unsubstituted and arabinose-substituted xylooligosaccharides were produced. GH10 gave a higher yield of short oligosaccharides (60% w/w) with xylobiose as the main product; xylobiose and xylotriose were the main products with GH11 (40% w/w). Thus, heat pretreatment combined with enzymatic hydrolysis can be used to produce arabinoxylan-oligosaccharides from rye bran that are potentially useful in functional foods.
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| 3. |
- Falck, Peter, et al.
(författare)
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Xylooligosaccharides from Hardwood and Cereal Xylans Produced by a Thermostable Xylanase as Carbon Sources for Lactobacillus brevis and Bifidobacterium adolescentis.
- 2013
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 61:30, s. 7333-7340
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Tidskriftsartikel (refereegranskat)abstract
- To compare xylans from forestry with agricultural origins, hardwood xylan (birch) and cereal arabinoxylan (rye) were hydrolyzed using two variants of the xylanase RmXyn10A, full-length enzyme and catalytic module only, from Rhodothermus marinus . Cultivations of four selected bacterial species, using the xylooligosaccharide (XOS) containing hydrolysates as carbon source, showed selective growth of Lactobacillus brevis DSMZ 1264 and Bifidobacterium adolescentis ATCC 15703. Both strains were confirmed to utilize the XOS fraction (DP 2-5), whereas putative arabinoxylooligosaccharides from the rye arabinoxylan hydrolysate were utilized by only B. adolescentis. Escherichia coli did not grow, despite its capability to grow on the monosaccharides arabinose and xylose. It was also shown that Pediococcus parvulus strain 2.6 utilized neither xylose nor XOS for growth. In summary, RmXyn10A or its catalytic module proved suitable for high-temperature hydrolysis of hardwood xylan and cereal arabinoxylan, producing XOS that could qualify as prebiotics for use in functional food products.
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| 4. |
- Gil-Ramirez, Alicia, et al.
(författare)
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Data on saponins, xylan and cellulose yield obtained from quinoa stalks after pressurized hot water extraction
- 2018
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Ingår i: Data in Brief. - : Elsevier BV. - 2352-3409. ; 20, s. 289-292
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Tidskriftsartikel (refereegranskat)abstract
- The data we present below are linked to our research paper “Integrated process for sequential extraction of saponins, xylan and cellulose from quinoa stalks (Chenopodium quinoa Willd.)” (Gil-Ramírez et al., 2018) [1]. The objective is to provide supplementary information in order to facilitate the comprehension of the central composite experimental design (rotatable 22) used in the integrated process of extractions. Two factors, temperature and time of extraction are considered in the design. The responses are the yield of saponin, xylan and cellulose. First, the desirable linear regression obtained by the observed vs. predicted yields plot for each variable response confirm the validation of the model (Fig. 1). Second, the data presented here through Standardized Pareto Charts (Fig. 2), provides information about the effect of the time and temperature, as well as their interactions, in the yield of saponins, xylan and cellulose obtained in an integrated sequential extraction.
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| 5. |
- Norlander, Siri, et al.
(författare)
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Effect of kilning on the macronutrient composition profile of three Swedish oat varieties
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Ingår i: Cereal Chemistry. - 0009-0352.
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Tidskriftsartikel (refereegranskat)abstract
- Background and ObjectivesKilning is crucial in oat processing, to prevent rancidity and extend shelf-life. This study examines kilning effects on the macronutrient composition in Swedish oat varieties Galant, Fatima, and Belinda. We compared two kilning methods: one mimicking industrial practice and a simplified version. We analyzed dietary fibers (arabinoxylan, β-glucan), protein and amino acids, lipid profile, lipase activity, and antioxidant capacity in these oat samples.FindingsDistinct compositional differences were found: Galant had low lipid content, Fatima had elevated lipid and protein levels with fewer carbohydrates, and Belinda was rich in β-glucan and dietary fibers. Both kilning procedures had similar impacts on all varieties, causing no major changes in dietary fiber or total protein content, but resulting in a 20% decrease in soluble proteins. Kilning decreased levels of several amino acids in Belinda, while the l-glutamate/glutamine ratio increased across all varieties. Lipid analysis showed minimal kilning-induced changes; yet, antioxidative capacity diminished. Both kilning methods effectively inactivated lipases.ConclusionsThese findings emphasize macronutrient variations among oat varieties and the effect of kilning on soluble proteins, amino acids, and antioxidative capacity.Significance and NoveltyThis study underscores the need for precise control in oat processing, crucial in plant-based protein and novel food development for optimal quality and yield.
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| 6. |
- Norlander, Siri, et al.
(författare)
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Novel thermostable GH5_34 arabinoxylanase with an atypical CBM6, displays activity on oat fibre xylan for prebiotic production
- 2023
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423. ; 33:6, s. 490-502
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Tidskriftsartikel (refereegranskat)abstract
- Carbohydrate active enzymes are valuable tools in cereal processing to valorise underutilized side streams. By solubilizing hemicellulose and modifying the fibre structure, novel food products with increased nutritional value can be created. In this study, a novel GH5_34 subfamily arabinoxylanase from Herbinix hemicellulosilytica, HhXyn5A, was identified, produced and extensively characterized, for the intended exploitation in cereal processing to solubilize potential prebiotic fibres; arabinoxylo-oligosaccharides (AXOS). The purified two-domain HhXyn5A (catalytic domain and CBM6) demonstrated high storage stability, showed a melting temperature Tm of 61 °C and optimum reaction conditions were determined to 55 °C and pH 6.5 on wheat arabinoxylan (WAX). HhXyn5A demonstrated activity on various commercial cereal arabinoxylans and produced prebiotic AXOS, while the sole catalytic domain of HhXyn5A did not demonstrate detectable activity. HhXyn5A demonstrated no side activity on oat β-glucan. In contrast to the commercially available homologue CtXyn5A, HhXyn5A gave a more specific HPAEC–PAD oligosaccharide product profile when using WAX and alkali extracted oat bran fibres as substrate. Results from multiple sequence alignment of GH5_34 enzymes, homology modelling of HhXyn5A and docking simulations with ligands XXXA3, XXXA3XX, and X5, concluded that the active site of HhXyl5A catalytic domain is highly conserved and can accommodate both shorter and longer AXOS ligands. However, significant structural dissimilarities between HhXyn5A and CtXyn5A in the binding cleft of CBM6, due to lack of important ligand interacting residues, is suggested to cause the observed differences in substrate specificity and product formation.
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| 7. |
- Paul, Catherine, et al.
(författare)
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A GH57 4-α-glucanotransferase of hyperthermophilic origin with potential for alkyl glycoside production.
- 2015
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Ingår i: Applied Microbiology and Biotechnology. - : Springer Science and Business Media LLC. - 1432-0614 .- 0175-7598. ; 99:17, s. 7101-7113
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Tidskriftsartikel (refereegranskat)abstract
- 4-α-Glucanotransferase (GTase) enzymes (EC 2.4.1.25) modulate the size of α-glucans by cleaving and reforming α-1,4 glycosidic bonds in α-glucans, an essential process in starch and glycogen metabolism in plants and microorganisms. The glycoside hydrolase family 57 enzyme (GTase57) studied in the current work catalyzes both disproportionation and cyclization reactions. Amylose was converted into cyclic amylose (with a minimum size of 17 glucose monomers) as well as to a spectrum of maltodextrins, but in contrast to glycoside hydrolase family 13 cyclodextrin glucanotransferases (CGTases), no production of cyclodextrins (C6-C8) was observed. GTase57 also effectively produced alkyl-glycosides with long α-glucan chains from dodecyl-β-D-maltoside and starch, demonstrating the potential of the enzyme to produce novel variants of surfactants. Importantly, the GTase57 has excellent thermostability with a maximal activity at 95 °C and an activity half-life of 150 min at 90 °C which is highly advantageous in this manufacturing process suggesting that enzymes from this relatively uncharacterized family, GH57, can be powerful biocatalysts for the production of large head group glucosides from soluble starch.
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| 8. |
- Ramirez, Alicia Gil, et al.
(författare)
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Integrated process for sequential extraction of saponins, xylan and cellulose from quinoa stalks (Chenopodium quinoa Willd.)
- 2018
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Ingår i: Industrial Crops and Products. - : Elsevier BV. - 0926-6690. ; 121, s. 54-65
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Tidskriftsartikel (refereegranskat)abstract
- World quinoa production is increasing due its high nutritional value. As a consequence, large quantities of stalks accumulate as unused byproducts. Here, we verify the presence of saponins in the stalks and present a biorefinery approach with quinoa stalks as feedstock, using an integrated processing scheme to separate saponins, xylan and cellulose. Saponins were extracted using pressurized hot water extraction (PHWE), optimized by a central composite experimental design (rotatable 22) with temperature and extraction time as factors. Xylan was extracted from the residual solid material after PHWE by an alkaline method using 0.5 M NaOH at 80 °C. Cellulose was purified from the remaining residuals using acetic and nitric acid at 120 °C, which resulted in recovery of white cotton-like cellulose, showing no need of further bleaching. The saponin yield was significantly increased at temperatures exceeding 110 °C, with highest amounts obtained at 195 °C (15.4 mg/g raw material). The yield in the following xylan extraction (maximum 120 mg/g raw material) was however significantly reduced when preceded by PHWE above 110 °C, indicating degradation of the polymer. Cellulose recovery (maximum 296 mg/g raw material) was less affected by variations in temperature and time in the preceding PHWE. The results obtained shows that tuning between saponin and xylan extraction is critical. This approach is foreseen to be applicable to the valorisation of residual fiber-rich biomass from various types of crops, besides quinoa.
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| 9. |
- Sajib, Mursalin, 1987, et al.
(författare)
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Valorization of Brewer's spent grain to prebiotic oligosaccharide: Production, xylanase catalyzed hydrolysis, in-vitro evaluation with probiotic strains and in a batch human fecal fermentation model
- 2018
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Ingår i: Journal of Biotechnology. - : Elsevier BV. - 1873-4863 .- 0168-1656. ; 268, s. 61-70
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Tidskriftsartikel (refereegranskat)abstract
- Brewer's spent grain (BSG) accounts for around 85% of the solid by-products from beer production. BSG was first extracted to obtain water-soluble arabinoxylan (AX). Using subsequent alkali extraction (0.5 M KOH) it was possible to dissolve additional AX. In total, about 57% of the AX in BSG was extracted with the purity of 45–55%. After comparison of nine xylanases, Pentopan mono BG, a GH11 enzyme, was selected for hydrolysis of the extracts to oligosaccharides with minimal formation of monosaccharides. Growth of Bifidobacterium adolescentis (ATCC 15703) was promoted by the enzymatic hydrolysis to arabinoxylooligosaccharides, while Lactobacillus brevis (DSMZ 1264) utilized only unsubstituted xylooligosaccharides. Furthermore, utilization of the hydrolysates by human gut microbiota was also assessed in a batch human fecal fermentation model. Results revealed that the rates of fermentation of the BSG hydrolysates by human gut microbiota were similar to that of commercial prebiotic fructooligosaccharides, while inulin was fermented at a slower rate. In summary, a sustainable process to valorize BSG to functional food ingredients has been proposed.
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