Journal of Applied Glycoscience
Online ISSN : 1880-7291
Print ISSN : 1344-7882
ISSN-L : 1344-7882
Volume 48 , Issue 3
Showing 1-6 articles out of 6 articles from the selected issue
  • Nyun Ho Park, Shigeki Yoshida, Yasuyuki Kawabata, Hyeon Jin Sun, Isao ...
    2001 Volume 48 Issue 3 Pages 253-262
    Published: July 01, 2001
    Released: February 23, 2011
    JOURNALS FREE ACCESS
    Twenty-three kinds of commercially available enzymes were subjected to the screening test for xylanolytic activities, namely, endo-β-xylanase, β-xylosidase, α-arabinofuranosidase and α-glucuronidase.The majority of the enzymes contained some of the activities. The above enzymes were also submitted to the hydrolyzable test on the arabinoglucuronoxylan of corn hull. Among them, Cellulase C-0901 (Sigma Chemicals) originating from Penicillium funiculosum, although lacking in a-glucuronidase, degraded the xylan very well, and released 80.5% of arabinose and 60.8% of xylose based on the component sugars of the xylan. On the other hand, Cellulase 'Onozuka' R-10 (Yakult Co.) originating from Trichoderma viride, although containing all of the xylanolytic activities, decomposed hardly any of the arabinoglucuronoxylan. According to these results, commer cially available enzymes contained high and various xylanolytic activities. However, the intensities of enzyme activity and hydrolyzable ability differed remarkably in the degradation of arabinogluc uronoxylan. In addition, Cellulase C-0901 was most suitable among them for the enzymatic hydrolysis of the xylan.
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  • Naofumi Morita, Chikako Hirata, Sang Ha Park, Toshio Mitsunaga
    2001 Volume 48 Issue 3 Pages 263-270
    Published: July 01, 2001
    Released: June 28, 2010
    JOURNALS FREE ACCESS
    Characteristics of dough and bread containing quinoa flour as a new foodstuff were studied using a rheometer, a farinograph, differential scanning calorimeter (DSC) and so on. Substitution of 7.5 to 10% of quinoa flour for hard-type wheat flour significantly increased the loaf volume of bread over that of the control, but more than 15% substitution distinctly decreased the volume. However, a combination of microbial lipase (75 ppm) and 15% substitution of quinoa flour resulted in a loaf volume that was distinctly more than that of the control. The hardness of bread crumbs increased in proportion to the amount of quinoa flour substitution. Combining the quinoa flour with lipase suppressed the staling of bread during storage and maintained softness by the liberation of monoglyceride from lipids. DSC data showed that substitution of quinoa flour resulted in a distinctly higher gelatinization temperature and gelatinization enthalpy compared with that of the control. As for the viscoelastic properties of the dough, combining quinoa flour (5 to 10% substitution) and lipase (75 ppm) resulted in reduction of compression stress and the modulus of elasticity, a slight softening of the dough, and slight decreases in the water absorption and the stability of the dough. From these results, a combination of quinoa flour substitution and lipase addition was found to improve bread qualities.
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  • Masatsugu Yamashita, Hideya Adachi, Takeshi Nakamura, Naomi Tokuriki, ...
    2001 Volume 48 Issue 3 Pages 271-278
    Published: July 01, 2001
    Released: February 23, 2011
    JOURNALS FREE ACCESS
    Many fatty acids in soy lysophospholipid (SLPL) prepared from soy phospholipid (SPL) using phospholipase A2 are unsaturated fatty acids such as linoleic acid and oleic acid. The complexing ability of SLPL-99 (99% hydrolysis of SPL) with starch is practically similar to that of glycerol monostearate. The properties of wheat starch gels blended with SLPL-99 using a Brabender Viscograph were analyzed by a differential scanning calorimeter (DSC), a rheometer, a polarizing microscope and a scanning electron microscope. DSC supported that SLPL-99 could form a complex with wheat starch. The rheological properties of the wheat starch gels blended with SLPLs of 48%, 64% and 89% of hydrolysis of SPL were subjected to a compression test. The breaking strength and stress of the wheat starch gels decreased as the degree of hydrolysis of SPL increased. Both parameters of gels with SLPL showed less change during storage compared to those of wheat starch alone gel. In Brabender amylogram, the gelatinization temperature of wheat starch increased as the degree of hydrolysis of SPL increased. The small changes in the above rheological properties of the gels during storage (5°C) and the rise of gelatinization temperature of the starch also suggested a formation of the complex of wheat starch with SLPL. These results suggested that SLPL has an ability to improve the quality of foods made from wheat starch through a complex formation.
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  • Hiroyuki Hashimoto, Akiko Yamashita, Koji Ikura, Chie Katayama, Masaru ...
    2001 Volume 48 Issue 3 Pages 279-285
    Published: July 01, 2001
    Released: February 23, 2011
    JOURNALS FREE ACCESS
    Time course of the positional isomers of α-galactobiose in α-linked galactooligosaccharide (α-GOS A) synthesized from galactose by the reverse reaction of α-galactosidase from Candida guilliermondii H-404 was analyzed by using p-aminobenzoic ethyl ester (ABEE)-conversion method. α-Galactobioses in α-GOS A consisted of α-1, 6-, 1, 3-, and 1, 2-galactobioses. α-1, 6-Galactobiose was the main product from an early reaction stage. α-1, 6-, 1, 3-, and 1, 2-Galactobioses were prepared from α-GOS A by an activated carbon chromatography.
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  • Takafumi Mizuno, Haruhide Mori, Mamoru Nishimoto, Hiroyuki Ito, Hiroka ...
    2001 Volume 48 Issue 3 Pages 287-291
    Published: July 01, 2001
    Released: February 23, 2011
    JOURNALS FREE ACCESS
    A putative α-glucosidase gene was isolated from the genomic library of Brevibacterium fuscumvar. dextranlyticum strain 0407. The gene, designated dexG, was located upstream of isomaltotriodextranase gene (dexT). The dexG contained an open reading frame of 1725 bp, and its deduced amino acid sequence (DexG) showed a high homology with the enzymes belonging to α-glucosidase Family I and I-like, especially oligo-l, 6-glucosidase from Bacillus sp. and dextran glucosidase from Streptococcus mutans. The DexG has four conserved regions shared with aamylases. In the cloned genomic fragment there were two other open reading frames, of which the deduced amino acid sequences showed a similarity with those of oligosaccharides membrane transporter proteins. The gene cluster consisting of the membrane transporter protein genes, dexG, and dexT, seems to participate in the degradation and utilization of dextran in this bacterium.
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  • Kwan Hwa Park
    2001 Volume 48 Issue 3 Pages 293-299
    Published: July 01, 2001
    Released: July 01, 2011
    JOURNALS FREE ACCESS
    Multiple amino acid sequence alignment and crystal structures of cyclodextrin (CD)-/pullulandegrading enzymes revealed the presence of an N-terminal extension of approximately 130 residuesnot found in ordinary α-amylases. Based on the results obtained from size exclusion chromatogra-phy and sedimentation equilibrium ultracentrifugation experiments, most of these enzymes aremainly in monomer-dimer-tetramer or monomer-dimer-dodecamer equilibrium and the unique Nterminal domain contributes to the formation of oligomeric state in this group of enzymes. Thestudies on the oligomerization and activity of the CD-/pullulan-degrading enzymes indicated thatthere was a significant correlation between the presence of monomer-dimer equilibrium and enzymatic activity. They also suggested that both the monomer and dimer were enzymatically active, but with different substrate preference for fl-CD and starch. The substrate preference of a dimerfor fl-CD was interpreted from the geometry of the active site in the homodimer, that is, small andcompact substrate molecules such as fl-CD might effectively access to the deep and narrow activesite of the dimeric enzyme. Therefore, it was suggested that the monomer-dimer equilibrium present in the reaction mixture reflected different multisubstrate specificity of CD-/pullulan-degrading Multiple amino acid sequence alignment and crystal structures of cyclodextrin (CD)-/pullulan degrading enzymes revealed the presence of an N-terminal extension of approximately 130 residues not found in ordinary α-amylases. Based on the results obtained from size exclusion chromatography and sedimentation equilibrium ultracentrifugation experiments, most of these enzymes are mainly in monomer-dimer-tetramer or monomer-dimer-dodecamer equilibrium and the unique Nterminal domain contributes to the formation of oligomeric state in this group of enzymes. The studies on the oligomerization and activity of the CD-/pullulan-degrading enzymes indicated that there was a significant correlation between the presence of monomer-dimer equilibrium and enzymatic activity. They also suggested that both the monomer and dimer were enzymatically active, but with different substrate preference for β-CD and starch. The substrate preference of a dimer for β-CD was interpreted from the geometry of the active site in the homodimer, that is, small and compact substrate molecules such as fl-CD might effectively access to the deep and narrow activesite of the dimeric enzyme. Therefore, it was suggested that the monomer-dimer equilibrium present in the reaction mixture reflected different multisubstrate specificity of CD-/pullulan-degrading enzymes.
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