Hitoshi Hashimoto

Stabilization and Solubilization of Lipophilic Natural Colorants with Cyclodextrins

The paper provides data on the practical utilization of the benefits of the molecular encapsulation of natural colorants by cyclodextrins. Experimental results on the stability of cyclodextrin complexed curcumin, curcuma oleoresin, β-carotene and carotenoid oleoresins against light-, heat- and oxygen prove the benefits of molecular encapsulation of colorants. The parent β-cyclodextrin stabilized most effectively the curcumines, while the stability of carotenoids was most effectively achieved by α-cyclodextrin complexation. Methylated β-cyclodextrin was found to be the most potent solubilizing agent for both carotenoids and curcuminoids.

Isolation and cultivation of a novel microorganism producing a maltopentaose-forming enzyme

SummaryA novel microorganism producing a maltopentaose-forming enzyme was screened from a soil sample. The enzyme produced by the bacteria formed maltopentaose from starch during the first stage of the reaction. The bacterium was characterized asPseudomonas sp. (KO-8940) on the basis of its morphological, physiological and biological properties. Culture conditions for enzyme production were investigated and established. The medium was composed of beef extract 0.8%, ammonium sulphate 1.0% and maltose 0.8% in tap water. Optimum conditions for bacterial growth were: initial pH 8.0, temperature 45°C, and 3 days cultivation with a rotary shaker (200 rpm). The broth supernatant obtained contained the maltopentaose-forming crude enzyme, with which 40% of starch was converted to maltopentaose.

Characterization of five isomers of branched cyclomaltoheptaose (β CD) having degree of polymerization (d.p.) = 9: Reinvestigation of three positional isomers of diglucosyl-β CD

It has been confirmed by methylation analyses and chemical syntheses that three isomers of branched cyclomaltoheptaose (beta CD) isolated from the mother liquors of a large-scale preparation of beta CD with Bacillus ohbensis cyclomaltodextrin glucanotransferase are 6(1),6(4)-di-O-(alpha-D-glucopyranosyl)-cyclomaltoheptaose (1), 6(1),6(3)-di-O-(alpha-D-glucopyranosyl)-cyclomaltoheptaose (2), and 6-O-(alpha-isomaltosyl)-cyclomaltoheptaose (4) instead of 6(1),6(2)-di-O-(alpha-D-glucopyranosyl)-cyclomaltoheptaose (3), which was erroneously characterized in an earlier paper. Compound 3 has been newly isolated from a glucosyl-beta CD mixture prepared by hydrolysis with glucoamylase of a maltosyl-beta CD mixture, synthesized from maltose and beta CD through the reverse action of pullulanase. Chromatographic behavior and spectral data (13C-n.m.r. and f.a.b.-m.s.) of these isomers of branched beta CD (1-4), as well as those of another isomer prepared by the reverse action of hydrolytic enzymes, 6-O-(alpha-maltosyl)-cyclomaltoheptaose (5), were compared.

Analyses of a Mixture of Glucosyl-Cyclomaltoheptaoses Prepared on an Industrial Scale

ABSTRACT A mixture of glucosyl-cyclomaltoheptaoses (β-cyclodextrins, βCDs) was prepared by glucoamylolysis of a mixture of maltosyl-βCDs which was produced on an industrial scale from maltose and β CD through the reverse action of Klebsiella pneumoniae pullulanase. Glucosyl-βCDs in the mixture were separated by HPLC on a reversed phase column and their molecular weights were measured by FAB-MS. In addition, the number of side-chains in each molecule was confirmed by methylation analysis and it was proved that the mixture comprised mainly of a monoglucosyl-βCD [G-β CD] and diglucosyl-β-CDs [(G)2-βCDs], and as a minor component triglucosyl-β CDs [(G)3-βCDs], and that G-, (G)2-, and (G)3-β CDs were produced in the ratios of 50%:45%:5%. The structures of three positional isomers of (G)2-β CD were established by HPLC analysis of partial hydrolyzates, 13C NMR spectroscopy, and chemical synthesis. Four regioisomeric (G)3-β CDs which could be isolated were characterized by 13C NMR spectroscopy.

The structure of high molecular weight dextrins obtained from potato starch by treatment with Bacillus macerans enzyme

Abstract Bacillus macerans enzyme (BME)-derived high molecular weight dextrins, which are by-products in the course of the industrial production of cylodextrins, were isolated and their chemical structures were characterized. Dextrin I was obtained in a yield of about 24% from BME-hydrolyzate (a mixture of dextrin and cylodextrins, 50% each) of potato starch by fractionation with an ultrafiltrator having a membrane of cut-off molecular weight 2.0 × 104. Dextrin II was obtained in a yield of about 15% from BME-hydrolyzate (a mixture of dextrins and cyclodextrins, 70 : 30) of Dextrin I by the same method. Dextrin I and II consisted of dextrin having molecular weights over 20 × 106 and dextrins having molecular weights 4 × 103−1 × 105 in the ratio of 80 : 12 and 66: 15, respectively. The results of hydrolysis by β-amylase and methylation analysis indicated that the average, exterior and interior chain lenghts of the dextrins having molecular weights over 20 × 106 and 4 × 103−1 × 105 from Dextrin I were 16.5, 8.2 and 7.3, and 11.5, 6.9 and 3.6, respectively, than those from Dextrin II were 13.6, 4.7 and 9.9, and 10.4, 5.1 and 4.3, respectively.

Chemical characterization of dextrins obtained from potato starch by treatment with Bacillus macerans enzyme

Abstract Potato starch was degraded with Bacillus macerans enzyme (BME), and the degradation product (a mixture of dextrins and cyclodextrins, 56.4:43.6) was separated by gel chromatography on Bio-Gel P-10 and Sepharose CL-2B into four fractions, I-1 (mol wt > 20 × 106), I-2 (mol wt 2 × 104-1 × 105), II (mol wt 1.5 × 103-2 × 104) and III (mol wt

Development and Application of Cyclodextrin Polymer

The objective of this study is to establish a technology for purifying substances which are difficult to separate in food processing by utilizing the inclusion and/or catalytic function of cyclodextrin (CD). We examined methods to synthesize CD polymers by fixing CD to four kinds of organic matrixes; acrylic polymer, agarose gel, vinyl polymer and chitosan beads. We applied these CD polymers to separating or purifing various substances from foods. Chitosan CD polymer was the most effective in our polymers.

Development of Durable Bait for Crustaceans

In order to develop a durable bait for crustaceans, CD (a mixture of cyclodextrin and dextrin) was included in the cuttlefish-extract to control the release rate of cuttlefish-extract. Furthermore, the cuttlefish-extract included CD was kneaded with hydrophilic urethane resin, resulting in the softness similar to raw fishes which are conventionally used as baits for crustaceans. The release rate of the cuttlefish-extract that included CD was low compared with the extract without CD, indicating the effectiveness for the long-term use of the extract. The usefulness of the present cuttlefish-extract bait was demonstrated by the increase catch of crustaceans.