Effects of hydrophilic surfactants [tetraglyceryl monooleate (MO-310), hexaglyceryl mono-stearate (MS-500), decaglyceryl monooleate (MO-750), and decaglyceryl monostearate (MSW-750)] were studied on viscosity and reflection changes, gel formation, and stability or retarda-tion of retrogradation after storage at 10°C or 25°C of gelatinized wheat starch. Hexaglyceryl monostearate (MS-500), at 0.1% concentration and at 20°C, or at 0.2% con-centration and at 10°C, retarded retrogradation of gelatinized wheat starch, forming viscous and stable solution. Viscosity stability of gelatinized wheat starch treated with various surfactants of different hydrophile-lipophile balance was tested after storage. Tetraglyceryl and decaglyceryl monoole-ates both improved viscosity stability and retardation of retrogradation. Based on the results, it was suggested that viscosity change or surface reflectivity of gelat-inized starch may be caused by differences in the distribution of molecular weight or in the mode of linkage. Hence, some ordered tendency may be absent in such phenomena. The acceleration of gel formation after gelatinization by the addition of surfactant to starch disper-sion may not be due to retrogradation, but probably to an intra- or intermolecular reaction between starch granules and surfactant. Surfactants increased turbidity and stability of opaque gelatinized starch. Reflectivity also increased correspondingly with amount of surfactant added, changes being large at the initial stage. When retrogradation index and retrograded turbidity of the gelatinized starch containing hexaglyceryl monostearate were tested after storage, some constant relationships were found between the increase in viscosity and the retardation of retrogradation.

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Starch samples were prepared from the underground tissues of the following: Asagi-zuisen, Freesia reflacta Klatt. (Iridaceae); To-syobu, Gladiolus gandavensis Van Houtt. (Iridaceae); and Dandoku, Canna indica Linn. var. orientalis Hook. f. (Cannaceae). Their yields were 24, 13, and 5%, respectively. These starches were examined as to granular size and shape, phosphorus and protein con-tents, the X-ray diffraction pattern, iodine coloration, swelling power, solubility, amylogram, the digestibility of the raw starches by glucoamvlase. and other nronerties. The starch of Asagi-zuisen was high in whiteness and slightly difficult to gelatinize or di-gest, and its granules appeared to be hard. Starch granules of To-syobu were fine and difficult to purify but similar to that of Asagi-zuisen in the properties relating to gelatinization. Dan-doku starch was composed of large flat granules and had the properties common to starches of the Zingiberaceae and Cannaceae showing high amylose and phosphorus contents and so on.

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Starch samples were prepared from the following: the root of Hama-nata-mame, Canavalia lineata DC. (Leguminosae) ; bulb of Suisen, Narcissus tazetta Linn. var. chinensis Roemer (Amaryllidaceae) ; tuber of Hama-suge, Cyperus rotundaus Linn. (Cyperaceae) ; and rhizome of Ki-ebine, Calanthe Sieboldii Decne. (Orchidaceae). Their yields were 7, 9, 14, and 13%, respec-tively. These starches were examined as to granular size and shape, phosphorus and protein con-tents, the X-ray diffraction pattern, iodine coloration, swelling power, solubility, amylogram, the digestibility of the raw starches by glucoamylase, and other properties. Starch granules of Hama-nata-mame were small in size, having high whiteness and high swelling power. Suisen starch was in swelling or dissolving at 60°C already. Hama-suge starch granules had a complicated shape and properties similar in gelatinization to sweet potato. Ki-ebine starch had a thin shape and low swelling power ; the viscosity on amylogram also was the lowest.

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The creep characteristics of Mochi prepared by a stamp and by mixer were studied. Mechanical models of each type of Mochi could by expressed by six-element models includ-ing a Hookean body, two pairs of Voigt bodies, and a Newtonian body. It was found that values for the instantaneous modulus of Mochi stored at 5 and -20°C were 10⁴ to 10⁶ and 10³ N/m², respectively, showing that the latter was significantly more viscous. The viscosity of the Newtonian body for the refrigerated Mochi was from 10⁸ to 1010 Pa-s, while that of the frozen type was from 106 to 10⁷ Pa·s. The shift factor-1/T relationship for the Mochi stored at 5°C was divided into two straight lines, and refraction point being observed at 50°C, however, such a phenomenon was not observed for the Mochi stored at -20°C. The permanent strain of the Mochi stored at 5°C was somewhat smaller than that of the Mochi stored at -20°C. These results indicate that Mochi stored at -20°C retained its initial physical properties like fresh Mochi.

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The physical characteristics after aging of Mochi prepared by several methods were studied. In the case of Mochi stored at 5°C, the degree of penetration decreased, but the hardness increased after storage. The Mochi stored at -20°C showed only a slight decrease in degree of penetration, while the refrigerated Mochi prepared by a mixer and the frozen type prepared by a stamp showed a low penetration. The cooking loss of the Mochi stored at 5°C decreased with increasing storage time, while that of the Mochi stored at -20°C was scarcely changea-ble. The Mochi prepared by the stamp showed a small cooking loss after storage at 5 and -20°C, respectively. Neither the Mochi stored at 5°C nor that stored at -20°C showed much change in moisture contents and water activity. The degree of gelatinization of the refrigerated Mochi somewhat decreased with increasing storage time, while that of the frozen type was little changeable. Both the Mochi stored at 5 and -20°C prepared by the mixer showed a small decrease in the degree of gelatinization. The crystalline structure of raw glutinous rice was classified as a type-A pattern, but this pattern disappeared upon heating and was transform-ed into a type-B pattern after storing at 5°C for one week. In the casd of the Mochi stored at -20°C, the crystallinity was never recovered. The viscosity of the Mochi stored at 5°C showed a maximum value of 800 to 1000 B. U., while the Mochi stored at -20°C showed a maximum value of 200 to 300 B. U. The viscosity of the latter reached a peak after storing for 72 hr, and then decreased with a further period of storage.

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The distribution of a-1, 4 chains in amylopectins from 4 kinds of tropical starches, i. e., from edible canna, arrowroot, cassava and sago, were examined. Potato and corn starches were used as controls. Each starch was debranched with isoamylase and then chromatographed on a Sephadex G-75 column. The eluates were fractionated into 3 peaks by measuring the reducing and total sugars and the iodine color reaction. Fraction I is thought to have been derived from amylose, and the content of fraction I agreed with the content of amylose by the amperometric iodine titration method except edible canna and corn starches. Fractions U and IQ are thought to have been derived from the long and short chains of amylopectin, and the average chain lengths of the combined II and Ilt fraction of potato and edible canna starches were approximately 18, while the values for the other four starches were approximately 16. The weight% values of fraction II of the potato and edible canna starches were 38.1 and 35.1%, respectively, and the mol% values were 16.2 and 14.8%. The weight% values of fraction II of the other four starches were 23.6-27.9% and the mol% values were 9.1-11.1% (refer to Table 2). These results show that potato and edible canna starches have more long chain branches than the other four starches. It is also shown that the edible canna, sago and corn starches were rich in branches, the chain length of which was longer than 10 and shorter than 20. In contrast, the potato and arrowroot starches were rich in short chains, with a chain length shorter than 10. The potato and edible canna starches showed X-ray diffraction patterns of the B type, while cassava, arrowroot, and corn starches were of A type, and sago starch of C type close to A. The relationship between the crystalline type and the average chain length of the amylopectins showed the tendency for the A type to have a shorter chain length than the B type.

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In order to establish a convenient method for estimating the intestinal digestibility of saccharides, hydrolysis of eleven kinds of saccharides by commercially available rat intestinal acetone powders was compared with that of two kinds of rat intestinal saccharidase preparations -mucosal homogenate and brush border membrane. The acetone powders showed about one-tenth lower and one-hundredth lower specific activity than that of mucosal homogenate and of brush border membrane, respectively. However, relative hydrolysis of various saccharides to that of maltose were almost similar among the three kinds of enzyme preparations, except a few saccharides hydrolyzed by isomaltase and trehalase. The results suggest that the acetone powders can be conveniently useful for preliminary evaluation of intestinal digestibility. Hydrolysis of fifteen kinds of saccharides by acetone powder preparations obtained from seven kinds of animals was also examined.

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The protection of a cyclomaltodextrin glucanotransferase (CGTase) bioreactor from bacterial contamination by the introduction of a high concentration of dissolved oxygen was investigated. The concentration of dissolved oxygen (DO) in the substrate (4% branched dextrin) was 80-90 ppm under a pressure of 2.5-2.8 kg/cm² at 50°C. The continuous operation of the bioreactor for about one month gave a good result. More specifically, the introduction of a high concen-tration of DO in the substrate could control the bacterial count therein under 4 x 10³ /ml. On the other hand, the activity of immobilized CGTase was not affected by high DO concentration. The bioreactor could attain a branched cyclodextrins production yield as high as 10% (w/w) for one month.

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Bacillus circulans F-2 has three unique properties : it produced G6 preferentially from solu-ble starch in the early stage of hydrolysis ; it digested potato starch granules effectively ; and it produced some kinds of amylase only when raw starches were used as a carbon sources. Therefore, the amylase and regulation of its synthesis in this bacterium were studied. We newly purified two amylases (amylase I and III) that are different from a major amy-lase (amylase II), having potent raw starch-digesting activity. Amylase I hydrolyzed a-1, 4-glucosidic and a-1, 6-glucosidic linkages att the same rate. Enzymatic properties of amylase III were almost the same as that of amylase II. The physiological significance of amylase is that they act synergystically in digesting starch granules. Potato and corn starch granules were cross-linked by epichlorohydrin to various extents (degree of cross-linking, DC=0.6-7.1). Using these starches as a carbon source for the cul-tivation of this bacterium, production of amylase was investigated. CLP (cross-linking potato starch, DC =4.0) induced 0.6 U/ml of amylase, which is 1.8 times as much as that on raw potato starch. B. circulans F-2 was found to produce amylase on maltose or soluble starch media if it is grown in appropriate condition such as dialysis and feeding cultivation, i. e., condition to afford the low bacterial growth. Its amylase synthesis is inducible by maltooligosaccharides and severely repressed by glucose. High amylase production was always accompanied by low a-glucosidase production and the absence of glucose in culture broth. In the presence of 1-deoxynojirimycin (DNM), an inhibitor of a-glucosidase activity, the bacterium produced a significant amount of amylase even in batch cultivation on maltose. From these results, the regulation of amylase synthesis in B. circulans F-2 is affected by its high sensitivity to glucose repression and by the production of a-glucosidase which leads to the formation of glucose.

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Starch sweeteners are manufactured by the hydrolysis of starch or starch-containing cereals using acid or enzyme as a catalyzer. There has been remarkable progress in the technology of the Japanese starch sweeteners industry. First of all, ion-exchange resin treatment was introduced to the refining process of the starch hydrolysate solution in 1953. The next most important progress was the technology of an enzyme application. At the end of 1958, almost dextrose manufacturing plants in Japan were operated by the acid hydrolysis method which is common in other countries. During the latter half of 1959, an enzymic process was introduced on an industrial scale, and acid hydrolysis was swiftly switched to the enzymic hydrolysis method until all of the dextrose manufacturing plants in Japan com-pleted the introduction of the enzymic process by the end of 1961. Dextrose is less sweet than sucrose and could not be used in every case as a substitute for sucrose. A high fructose-containing syrup (HFCS) was prepared by an enzymic isomerization of glucose (dextrose content more than 95%) by glucose isomerase in 1965. 55 F HFCS (fructose content 55%) is a high fructose-containing syrup having a similar degree of sweetness to that of inverted liquid sucrose. Maltose, maltooligosaccharides, and so-called isomaltooligosaccharides are also prepared by the suitable enzymic process. Nowadays, a total 2 million tons per year of the starch sweeteners are manufactured in Japan and HFCS is accounts for about half of this amount.

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Twelve cellulase components and a Jl-glusosidase were extensively purified to essential homo-geneity from a commercial crude cellulase preparation from Trichoderma viride (Meicelase) by a multi-step procedure involving Amberlite CG-50 and DEAE-Sephadex A-50 column chromato-graphic fractionations, affinity chromatography, isoelectric focusing, and gel filtration on Bio-Gel P-100. The purified enzymes were designated as cellulases I-al, I-a2, I-a3, I-b1, I-b2, II-al, II-b, II-c, III-a2, III, and IV, and were judged to be homogeneous on polyacrylamide gel and SDS-polyacrylamide gel as well as ampholine electrophoresis. All purified cellulases were com-pletely free from jS-glucosidase. The physicochemical and enzymatic properties of the purified enzymes were studied in detail and compared with each other. Of the twelve cellulase components, cellulases II-b and III were found to be the "key enzymes" in the cellulase system of T, viride. The purified cellulase II-b possessed a potent ability to produce glucose specifically from /l-D-cellobiose through enzy-mic reversion and transcellobiosylation without any participation of /S-glucosidase. It was strongly suggested that cellulase II-b would play an important role in glucose production in the enzymatic degradation of native cellulose. On the other hand, the purified cellulase III showed a high level of glucose production from crystalline cellulose by a multi-step reaction involving condensation followed by hydrolysis. The purified cellulase III corresponded absolutely to the known cellobiohydrolase (CBH, EC 3. 2. 1. 91) fudging from its physicochemical properties and substrate specificities. Even though cellobiose was the predominant product in the initial hydrolysis stage, it was clearly demonstrated from the experimental results that cellulase III was not 1, 4-β-D-glucan cellobiohy-drolase (CBH) but rather essentially a glucose-forming enzyme. Consequently, so-called CBH does not exist, at least in the cellulase system of T. viride. Now, we present the proposed scheme of the cooperative action by cellulases from T. viride in converting native cellulose to glucose.

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