Lyophilized-slices and starch granules from bulbs of 3 varieties of konjac, Zairai, Akagi, and Haruna, were prepared. Each slice was observed by scanning electron microscopy (SEM) and the properties of the starch granules were examined. The results obtained were as follows: 1) The mean particle size of konjac starch was 1.2-1.3 being very small. 2) On SEM, starch granules in the slices of konjac bulbs were found to be polygonal in shape. In particular, the small polygonal granules in the slices of Zairai were assembled like a soccer ball. 3) The susceptibility of the konjac starch granules to hog pancreatin was very high in the early stage of the reaction. 4) The solubility of konjac starch granules was higher than those of normal maize starch at 70 and 80&°C, and the swelling power was also higher than those of normal maize starch at 80 and 90&°C. Their solubility and swelling power increased rapidly from 70 to 80&°C. 5) The amylose contents of konjac starches from 3 varieties, determined by amperometric titration and gel chromatography were 17.4-18.2% and 18.5-19.4%, respectively.

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A trehalase was highly purified from Bacillus sp. T3 newly isolated from soil at 50°C. The molecular weight of the trehalase was estimated to be 58, 000 Da by SDS-polyacrylamide gel electrophoresis and 52, 000 Da by gel filtration. The pI of the enzyme was 4.8. Its optimum pH and temperature were around 7.8 and 50°C, respectively. The enzyme was stable between pH 6.0-9.5, and below 55°C. The Km value for trehalose was 3.0 mM. The enzyme was inactivated by Cu²⁺ + and Hg²⁺ .

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Commercially available yeasts normally contain approximately 10% dry weight of trehalose. For the purpose of obtaining liquid trehalose economically and safely, without using heat or an organic solvent, we used a high-pressure treatment to extract the trehalose, with inactivating trehalase. Our results showed that trehalase is inactivated by the application of a minimum of 700 MPa and that trehalose is not hydrolyzed even at pressures as high as 1500 MPa. Using high-pressure treatment, therefore, we have succeeded in extracting trehalose from yeast at 12% dry weight when 700 MPa is applied for 10 min at 30°C. It has been confirmed that high-pressure treatment is very effective for simultaneously inactivating trehalase and extracting trehalose.

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α-CD inclusion complexes of fatty acid methyl/ethyl esters (FAME) were prepared at various molar ratios. X-ray diffractograms of the complex powders showed a specific reflection peak at 28=7-8°, which characterized the α-CD inclusion complexes of various FAME. The intensity of the peak of each FAME complexed powder correlated well against the reduced inclusion fraction (i.e. the ratio of the inclusion amount obtained by gas chromatography to its maximum value) for each FAME into α-CD.

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The effect of hydrolyzed guar gum on the frequency and feeling of defecation was assessed in 65 healthy volunteers, using a beverage containing 5 g of hydrolyzed guar gum. The study was done in accordance with the Helsinki Declaration. The experiment was carried out over 6 weeks, divided into three periods: during the first and third periods (both 2 weeks) the bowel movement status without the beverage was observed; during the second 2-week period, the beverage was given to the subjects. The subjects were divided into two groups: one was given 5 g of hydrolyzed guar gum daily; the other was given 15 g of hydrolyzed guar gum daily. Questionnaire data on the effect on bowel movement were analyzed according to defecation frequency, fecal excretory feeling, abdominal condition, fecal volume, defecation time and fecal hardness. The frequency of defecation in both groups increased significantly during the beverage intake period, and the fecal excretory feeling was improved by hydrolyzed guar gum. The defecation time tended to decrease in the group receiving 5 g daily, while it was significantly reduced in the group receiving 15 g daily. The fecal volume in both groups increased significantly during the beverage intake period. As regards fecal hardness, feces tended to soften in the group with hard feces, and harden in the group with soft feces. Five grams of hydrolyzed guar gum taken daily began to change bowel movement within a few days. After 2 weeks, it appears that hydrolyzed guar gum intake improved frequency and feeling of r1PfeCatinn

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To study the structure of yeast (Saccharomyces cerevisiae) mannan, two kinds of the mannan degrading enzymes have been isolated from soil bacteria. An αl, 2-n-mannosidase that hydrolyses specifically αl, 2-linked mannosyl side chains; it has a molecular weight of 380, 000 and is composed of two identical 190, 000 subunits. An endo-al, 6-D-mannanase that hydrolyses al, 6-linked mannan back bone and it consists of a single polypeptide chain with a molecular weight of 131, 000. S. cerevisiae cell wall mannoprotein was selectively hydrolyzed by the al, 6-D-mannanase and an endo-β-N-acetylglucosaminidase to produce the linkage region between protein and polysaccharide parts. The structure of the linkage region was studies by conventional methods including NMR, methylation analysis, acetolysis, and sequential digestion of α- or β-mannosidases. The structures of the residual polysaccharide part and α-linked mannooligosaccharides were also characterized.

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Microbial endoglycosidases are useful for elucidating the structure and function of the oligosac-charide chains of glycoconjugates. We found many types of endoglycosidases in culture broths of various microorganisms isolated from soil. Endo-β-N-acetylglucosaminidase was found in the culture broth of Flavobacterium sp. The enzyme could liberate the asparagine-linked oligosaccharides of various glycoproteins. Novel endo-β-N-acetylglucosaminidase was also found in the culture broth of Mucor hiemalis. Unlike most microbial enzymes, it could act on complex type oligosaccharide chains that exist in most glycoproteins of animal tissues. Endo-α-N-acetylgalactosaminidase which releases the O-glycosidic oligosaccharide from various glycoproteins was found in the culture broth of Alcalig-enes sp. Endoglycoceramidase was found from Corynebacterium sp. as a membrane-bound enzyme. It could liberate oligosaccharide from various glycosphingolipids. This paper describes the applications of these microbial endoglycosidases to glycobiology.

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The generic term "oligosaccharides" is customarily used for saccharides which are composed of 2-10 monosaccharide residues joined through glycosidic bonds. Research in the production of oligosac-charides for food was started around 1970-75 in Japan and several oligosaccharides were produced on an industrial scale during the 1980s. Recently, various kinds of biologically active new oligosac-charides have been developed one after another and some of these saccharides are now produced from various raw materials on a large scale using a bioreactor system. I will review the recent progress of oligosaccharides in Japan, and also I will describe the functional characteristics and uses of oligosaccharides produced from starch in this paper.

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