| 1. |
- Jiang, Jian-xin, et al.
(författare)
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Structural and thermal characterization of galactomannans from genus Gleditsia seeds as potential food gum substitutes
- 2011
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Ingår i: Journal of the Science of Food and Agriculture. - : Wiley. - 1097-0010 .- 0022-5142. ; 91:4, s. 732-737
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Seed galactomannans are preferred hydrocolloids since they are comparatively cheap, non-toxic, eco-friendly and non-polluting during production and application. Galactomannans from seeds of three species of Gleditsia, namely G. sinensis, G. microphylla and G. melanacantha, were characterized in terms of structural and thermal properties. RESULTS: Gleditsia polysaccharides were characterized using both chemical and chromatographic methods, as well as Fourier transform infrared, H-1 nuclear magnetic resonance (NMR) and C-13 NMR spectroscopy, and it was shown that they consist of D-mannopyranose and D-galactopyranose residues. The mannose/galactose (M/G) ratio of galactomannans was 3.25, 3.31 and 2.30, respectively. It was also found that these polysaccharides differ from one another in values of M-w, M-n and polydispersity. X-ray diffraction confirmed the amorphous nature of Gleditsia galactomannans, although G. sinensis galactomannan showed a high crystallinity. Thermal analysis of the galactomannans by differential scanning calorimetry illustrated that their endothermic peaks ranged from 290 to 320 degrees C. CONCLUSION: Gleditsia polysaccharides are neutral galactomannans. The higher value of M/G ratio from G. sinensis and G. microphylla indicates that their gums offer an excellent alternative for locus bean gum. (C) 2011 Society of Chemical Industry
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| 2. |
- Jian, Hong-lei, et al.
(författare)
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Influence of dehulling pretreatment on physicochemical properties of Gleditsia sinensis Lam. gum
- 2011
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Ingår i: Food Hydrocolloids. - : Elsevier BV. - 0268-005X. ; 25:5, s. 1337-1343
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Tidskriftsartikel (refereegranskat)abstract
- The seeds of Gleditsia sinensis Lam., widespread in China, are an important source of galactomannans. G. sinensis gum was extracted from whole seeds using baking, boiling water and acid dehulling pretreatment, respectively. The physicochemical properties of the three isolated G. sinensis gums were studied to evaluate three pretreatment methods. The results illustrated that the properties of G. sinensis gum were significantly influenced by dulling method (p < 0.05) including the yield, M/G ratio, viscosity, chemical composition and molecular weight. Power-law model (sigma = k.gamma(n)) was applied to the rheological measurements, which indicated that solutions of Gb, Gw and Ga gum behaved as pseudoplastic fluids at the concentration of 0.5% (w/v). The gum obtained by acid pretreatment (Ga) had the lowest yield of 20-24% (w/w). However Ga showed a pronounced shear-thinning behavior and particularly higher viscosity compared with the gums extracted by baking pretreatment (Gb) and boiling water dehulling method (Gw). The mannose to galactose ratios (M/G ratio) for Gb, Gw and Ga were found to be 4.5, 4.4 and 6.9, respectively. The highest molecular weight of 3.31 x 10(6) Da was observed for the galactomannans of Gb. (C) 2010 Elsevier Ltd. All rights reserved.
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| 3. |
- Schoch, Conrad L., et al.
(författare)
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Finding needles in haystacks: linking scientific names, reference specimens and molecular data for Fungi
- 2014
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Ingår i: Database: The Journal of Biological Databases and Curation. - : Oxford University Press (OUP). - 1758-0463. ; 2014:bau061, s. 1-21
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Tidskriftsartikel (refereegranskat)abstract
- DNA phylogenetic comparisons have shown that morphology-based species recognition often underestimates fungal diversity. Therefore, the need for accurate DNA sequence data, tied to both correct taxonomic names and clearly annotated specimen data, has never been greater. Furthermore, the growing number of molecular ecology and microbiome projects using high-throughput sequencing require fast and effective methods for en masse species assignments. In this article, we focus on selecting and re-annotating a set of marker reference sequences that represent each currently accepted order of Fungi. The particular focus is on sequences from the internal transcribed spacer region in the nuclear ribosomal cistron, derived from type specimens and/or ex-type cultures. Re-annotated and verified sequences were deposited in a curated public database at the National Center for Biotechnology Information (NCBI), namely the RefSeq Targeted Loci (RTL) database, and will be visible during routine sequence similarity searches with NR_prefixed accession numbers. A set of standards and protocols is proposed to improve the data quality of new sequences, and we suggest how type and other reference sequences can be used to improve identification of Fungi.
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