The viscograms of linseed oil-treated potato starch were greatly changed by difference of the oil with γ-irradiation. The viscograms of the irradiated potato starch containing 2.28% oil showed that the maximum viscosity at 40 krad was slightly larger than that of the control (non-irradiated sample) and moreover at the dosage of more than 80 krad it was less than that of the control. On the other hand, the viscograms of the irradiated potato starch containing 4.92% oil showed that the maximum viscosity greatly decreased compared with that of the control. In the viscograms of the irradiated corn starch containing 3.5% oil, the maximum viscosity first increased at 40 krad compared with that of the control and then it decreased gradually with an increased dose of irradiation. In the viscograms of the defatted samples of both starches with and without oil treatment before irradiation, the maximum viscosity decreased gradually with an increased dose of irradiation. Moreover, the ratio of decrease of maximum viscosity under irradiation was greater in the oil treated sample than it was in the untreated. The same was the true in the case of the mean DP and the β-amylolysis. These results suggested that the decomposition of starch molecules by γ-irradiation was enhanced by linseed oil in starch granules.

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Cyclodextrin glucanotransferase [EC. 2. 4. 1. 19] from Bacillus stearothermophilus TC-60 was purified by starch adsorption, DEAE-Sephadex column chromatography and Biogel P-150 gel filtration. Subunit molecular weight of the purified enzyme was estimated to be 68, 000 by sodium dodecylsulfate-polyacrylamide gel electrophoresis. The isoelectric point of the purified enzyme was pH 4.5. The enzyme was most active at pH 6.0 and at 70°C, and stable up to 50°C at pH 7.0 and in the range of pH 7.0-9.2 at 40°C in the 2-hr incubation . The results of the trichloroethylene-test and the Tilden-Hudson test suggest that the enzyme from B, stearothermophilus produced cyclodextrins in a different ratio from the enzymes of B, megaterium. and B. macerans IFO 3490.

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By using the highly purified cyclodextrin glucanotransferase ([EC. 2. 4. 1. 19], CGT-ase) from Bacillus stearothermophilus TC-60, intramolecular and intermolecular transglycosylation, hydrol ytic reaction on starch and α-, β- and γ-CD and disproportionation reaction on maltotriose were investigated to compare with those of CGT-ases from B. megaterium, B. circulans ATCC 9995 and B. macerans IFO 3490. CGT-ase from B, stearothermophilus was found to be a novel type of CGT-ase, different from CGT-ases of B. megaterium, B. circulans and B. macerans.

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Relationships between susceptibility of starch-granule to pancreatin and X-ray diffractogram, photopastegram, absorptivity at 680 nm of iodine complex ("blue value"), or morphology by scanning electron microscopy (SEM) of various starch granules were examined . The results obtained were as follows. 1) In general, X-ray diffractograms of starch granules relatively susceptible to pancreatin were A type, those of starch granules insusceptible to pancreatin were B type and those of starch granules intermediately susceptible to pancreatin were C type. 2) Photopastegrams showed two-step increase of transmittance for starch granules relatively susceptible to pancreatin and one-step increase of transmittance for starch granules insusceptible to pancreatin. However, there was no statistically significant correlation between susceptibility of starch-granule to pancreatin and initial temperature for gelatinization as determined by photopaste graphy of various starch granules. 3) By SEM of various starch granules, we confirmed that starch granules susceptible to pancreatin showed polygonal shapes but starch granules insusceptible to pancreatin had smooth surfaces and round or oval shapes.

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The fractionation of maltosaccharides by gel filtration is described. The procedure is based on the use of Bio-Gel P-2, P-4 and Toyopearl HW-40 gel in a properly designed column with water as an eluent, at 55°C. In the 4-m Bio-Gel column chromatography, the fractionation of maltosaccharides up to DP 25 was achieved with good resolution. It was possible to separate each component of the malto saccharide mixture when less than 500 mg as dry solids was charged on this column. The column was eluted at different flow rates, between 22 and 24 ml/hr and the effluent was monitored by the differential refractometer system. At these flow rates, the column pressure was below 5 kg/cm². In case of large scale fractionation of oligosaccharides by Toyopearl HW-40 gel filtration with a 1- or 2-m column, maltooligosaccharides (G₄, G₅ and G₆) and cyclodextrins (α-, β- and γ-CD) could be obtained with above 99 .9% purity. However, it is recommended that less than 2g of the saccharicle mixture should be charged on to a 2-m Toyopearl HW-40 gel column for good resolution of these oligosaccharides.

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It was indicated in the previous papers that the gelatinization temperature (GT) of starch in potatoes which contained a high percentage of water, could be successfully determined by differential thermal analysis (DTA). In the present experiments, the authors applied the DTA to the study of thermal behavior of starch in foods (rites, buckwheat, wheat flours and processed noodle foods) of relatively low moisture content and so high content of other matrix components, without any isolating operation. The DTA curves of specimens of rites, wheat flours and processed noodle foods indicated single endothermic peaks specific to species. Those patterns agreed with those of starches isolated from foods, except for slight shifts of some degrees to higher temperature region, and accompanied by disappearance of polarization pattern of starch. The DTA curve of buckwheat indicated a broad peak of endotherm. It can be said that the DTA curves of those foods reflect the endothermic signals of the gelatinization of starch in food without confusion with the signal of other matrix components. From further examinations, the following findings were obtained. 1. Milled rice indicated the onset GT increase from 60°C to 64°C after storage at room temperature for 3 years. 2. The onset GT of wheat flour doughs increased from 60°C to 68-71°C or 65-68°C with addition of 10% sodium chloride or carbonate respectively. 3. The onset GT of processed noodle foods were as follows: Spaghetti, 59-60°C; Japanese Somen, Hiyamugi, and raw and dried Udon, 61-64°C; Chinese Lao mien. 63-65°C; Tananese dried Soba. 64-65°: and Chinese Mi fen 50°C.

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Cereals with waxy (i. e, glutinous) endosperm, such as rice, foxtail millet and common millet, are staples commonly found not only in Japan but also in various countries of East Asia. In the present article the geographical distributions of the waxy endosperm of seven species of cereals and their ethnobotanical significance are discussed. Based on recent findings and analyses of waxy and non-waxy perisperms in Anraranthus hypochondriacus collected in Nepal, the origin and dispersal of waxy perisperm of this species are also reported. Waxy endosperm is found in Oryza sativa (rice), Zea nays (maize), Hordeum vulgare (barley), Coix lacryma-jobi var, nta-yuen (Job's tears), Setaria italica (foxtail millet), Panicum uniliaceum (common millet) and Sorghum bicolor (sorghum). Cryza sativa: The waxy endosperm of Oryza sativa was first reported by Gris in 1860. After examining many indigenous varieties to nine geographical regions ranging from India to Japan, Iizuka et al. (1977) concluded that (1) in India, Sri Lanka and Nepal there were almost no waxy forms, (2) waxy varieties were abundant in samples from Indochina, Thailand and Burma, whereas (3) rather high frequencies were observed for non-waxy varieties from Japan and northern China. Watabe (1967) indicated that glutinous rice cultivation in Southeast Asia appears to center in northern and northeastern Thailand and Laos spreading to the surrounding regions of Burma, Yunnan, Vietnam and Cambodia. Zea mays: Waxy maize was found by Collins (1909) in a collection of specimens from China. This type of maize has generally been reported from northern Burma, Assam, China, Korea and Japan. Maize was domesticated first in the New World, but the waxy variety clearly originated from East Asia having developed after the introduction of maize from the New World. Hordeum vulagre: The waxy form of barley is found only in China, Korea and Japan. In Japan it was found sporadically in areas facing the Seto Inland Sea and in northern Kyushu. According to Nakao (1950), this form can be classified into three varieties which have in common naked and purple-colored grains. Coix lacryna jobi var. ma-yuen: Kempton (1921) observed both waxy and non-waxy forms of Job's tears in samples from Burma, India, the Philippines and China. However, in East Asia, only the waxy form is commonly grown. Setaria italica: Of the 406 samples collected by the author at various locations ranging from Europe to East Asia, 221 had waxy endosperm (54.4%) and 185 had non-waxy endosperm (45.6%). The former was found in Japan, Korea, China, Formosa, Luzon Island (the Philip-pines) and Thailand, but only the non-waxy form was isolated in samples from the Batan Islands (the Philippines), Halmahera Island (Indonesia), Nepal, India, Afghanistan, Central Asia and Europe. The obvious gaps in the geographical distribution of the waxy form of foxtail millet have been recognized in two places. One is the Bashi Channel between Formosa (includ-ing the Lan Yi Islands) and the Batan Islands. The other seems to be between Nepal-India and Assam. It is assumed that the gap at the Bashi Channel is related to the importance of the waxy variety in the ritual life of the native tribes inhabiting the Formosan mountains and the Lan Yu Islands. No reasonable explanation, however, of the other can be given at present. Panicum miliaceum: In spite of the wide occurrence of this species in Eurasia, studies of the geographical distribution of its waxy varieties have not been made. To the extent that could be examined by this study, the waxy form was detected only in specimens from Japan, Korea and China. The small number of samples from Afghanistan, Central Asia and Europe included only the non-waxy form. Sorghum bicolor: The waxy form of this species has been reported from Java, India, the Philippines, China and Japan. According to the present survey, the waxy form is very common in Korea and Japan. However,

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It is supposed that gelatinization of starch, a typical thermal reaction, can be studied effec-tively using techniques of thermal analysis. We applied differential thermal analysis (DTA) to examine thermal behavior of starch. The DTA curve of starch heated in an air-tight cell on DTA apparatus, indicated single endothermic peak accompanied by disappearance of polarization pattern of starch. From this result it was concluded that the DTA curve was suitable to determine gelatinization process of starch. In DTA, gelatinization characteristics of starch could be represented in three temperatures; onset temp. (T_o), peak temp. (T_p) and recovery temp, (T_r) of the DTA curve, To was neither influenced by varying heating rate (2-15 deg/min), varying amount of sample (0.8-14.3 mg) nor varying concentration of starch (2, 6-50, 6%) within a standard deviation of it. Ta was relatively near the value of photopastegraphy and T_p was near values of initial and 20 BU of amylography. However, T_r was higher than temp. at maximum viscosity of amylography. The gelatinization temp. (GT) of starch immersed in many kinds of salts solutions could be determined successfully by DTA in aqueous system. From these results, difference between these salts in the influence on the GT could be demonstrated quantitatively by the critical concentration index defined as the index of minimum concentration required to make a change of the GT. This index was in linear relation with the lyotropic value and the hydration number of ions, and furthermore correlated very closely with the B-coeficient of salts, The GT of starch treated with a salt of high B-coefficient increased as the content of salt retained by starch granule increased, while the endothermic heat of gelatinization (ΔHg) was unchangeable essentially. However, in the case of a salt with low 13-coefficient, the GT and ΔHg were decreased, which were accompa-nied by the corresponding decreases of the intensity of X-ray diffraction. The results suggested that the salt retained by starch granule affected the structural stability of starch micelle. The DTA curves of specimens of potatoes, rices, wheat flours and processed noodle foods indicated single endothermic peaks specific to species. These patterns agreed with those of starches isolated from foods, except for slight shifts of some degrees to higher temp, region, and accom-panied by disappearance of polarization pattern of starch. The DTA curve of buckwheat indicated a broad peak of endotherm. It was declared that the DTA curve of those foods reflected the endothermic signals of the gelatinization of starch in food without confusion with the signal of other matrix components. Potato and milled rice indicated some increases of the GT after storage. The GT of wheat flour Boughs increased with addition of sodium chloride or carbonate. The GT of processed noodle foods determined successfully.

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The topics from the results of the studies conducted by the author during the past three decades are reviewed. The studies are mainly related to oligo- and polysaccharides and include the following projects: 1. Glucobioses in Japanese rice wine (Sake) and Koji extract. 2. Chemical synthesis of kojibiose and nigerose. 3. Acetolysis of gluco-oligosaccharides and glucans. 4. Structural studies of Konjac glucomannan. 5. Biochemical studies of dextrans. 6. Biosynthesis of fungal glycogen. 7. Structural studies of cell wall polysaccharides. 8. Biochemical studies of plant cell wall polysaccharides. 9. Some polysaccharide degrading enzymes including an α-1, 3- glucanase of a Streptomyces species, a dextranase capable of splitting α-1, 2-linkage at the branch point, and a /3-glucosidase of Pyricularia rr yzae.

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