Starch samples were prepared from three kinds of Pteridophyta : stipule of Ryubintai, Angiopteris lygodiifolia Rosenst. ; rhizome of Oni-yabu-sotetu, Cyrtomium faleatum Presl ; and Oo-iwa-hitode, Colysis pothifolia Presl ; the yields were 6, 5, and 4%, respectively. These starches were examined as to granular size and shape, phosphorus and protein contents, 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 Ryubintai were large in size with various shapes, and showed very high and stable viscosity on amylogram. Oni-yabu-sotetu starch was gelatinized at comparatively lower temperature, and resembled Satuma-imo starch in other properties except its smaller size . Oo-iwa-hitode starch contained high amounts of amylose, hardly dissolved in hot water, and did not show a rise of viscosity on amylogram in 6% paste.

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Starch samples were prepared from the tuberous root of Turu-dokudami, Polygonum multiflorum Thunb., Momiji-hirugao, Ipomoea cairica Sweet, and Yama-no-imo, Dioscorea japonica Thunb. ; the yields were 6, 4, and 20%, respectively. These starches were examined as to granular size and shape, phosphorus, and protein contents, the X-ray diffraction pattern, iodine coloration, swelling power, solubility, amylogram, the digestibility of the raw starches by glucoamylase, and other properties. Turu-dokudami starch was comparatively small in size and swelled easily . Momiji-hirugao starch had similar properties to that of Satuma-imo belonging to the same genus, except that the former showed B-type of X-ray diffraction pattern. Starch granules of Yama-no-imo had a fairly large size with smooth surface, and seemed to have a hard structure.

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Corn starch-granules remaining after digestion by Chalara paradoxa glucoamylase were observed by electron microscopy. Scanning electron microscopy showed that the starch-granules had a lamellar structure of less susceptibility against the glucoamylase digestion. These lamellar structures were heterogeneous in thickness and organization. There were thin and thick layers. The thin layers of the lamellae were 50 nm to 200 nm thick with connections between them. The layers were not regularly layered, but were transversed. Several thin layers were combined and they composed a 300 nm to 500 nm thick layer. Thin sections of starch-granules, observed by transmission electron microscope, also confirmed this lamellar structure.

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Rheological properties of pastes of glutinous rice, waxy corn, and cassava starch were mea-sured with rheometers. The temperature at which viscosity increased was observed on viscogram to be highest for waxy corn starch, followed by cassava starch, and glutinous rice starch. Waxy corn starch showed the highest maximum viscosity, while cassava starch showed the largest setback upon cooling. Changes in degree of gelatinization of various starch samples, which had been stored at 5 and -20°C for 72 hr, were very small. This fact suggests that these materials would hard-ly suffer from retrogradation. The spinning distance of a starch paste increased with an increase in concentration. The increasing ratio of glutinous rice starch was the highest, followed by cassava starch and waxy corn starch. Cassava starch had the highest elastic modulus and viscosity. The apparent activation energy of glutinous rice, waxy corn, and cassava starch was 38. 60, 28. 30, and 76.35 kJ/mol, respectively. Though dynamic modulus and the dynamic loss of each starch paste increased with an in-crease in frequency, cassava showed significantly high values, compared with those of glutinous rice and waxy corn. The tanδ of waxy corn and cassava starch increased with an increase in frequency, while glutinous rice starch was scarcely changeable. Cassava starch showed the smallest tanδ.

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The relationship between the amylases in rice and the mechanism of degradation of starch in cooking of rice remains to be clarified. In this paper, α-amylase [EC 3.2.1.1] I and II were purified from polished rice granules by ammonium sulfate and acetone fractionation, DEAE-cellulose column and Sephadex G-75 gel chromatographies. The molecular weights of the purified a-amylase I and II were estimated to be 46, 000 and 61, 000 by Sephadex G-75 gel chromatography and their K_m values for soluble starch were 3.5 and 2.3 mg/ml, respectively. And α-amylase II was more stable than a-amylase I against temperature.

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α-Glucans extracted from the endosperm of Proso and Indian millets with cold water were analyzed by methylation and enzymic hydrolysis. Both α-glucans had about 12, 500 of weight average molecular weight, and 3-20 of chain-length distribution which was revealed by gel chromatography of the pullulanase and isoamylase digests. A ratio of maltose and maltotriose to higher oligosaccharides in the pullulanase and isoamylase digests of the jS-limit dextrin supported Meyer's model for the structure of these a-glucans.

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Cell-bound isopullulanase of Aspergillus niger was purified from the mycelia in a sub-merged culture through 1) solubilization of the enzyme with Novozyme 234, 2) P-cellulose (pH 3.8) and DEAF-cellulose (pH 5.5) chromatography, 3) displacement chromatography (changing pH from 6.2 to 4.0) and gel filtration on Bio-Gel P-100 (pH 5.5). Purified enzyme showed a single glycoprotein band, stained with Coomassie Brilliant blue and Na104-Schiff's reagent, on PAGE and a single peak on HPLC using TSK-gel G-3000 Swxz. Substrate specificity of cell-bound and extracellular isopullulanase was the same on pullulan, panose (GlcP(α1→6)Glcp(α1→4)Glc), and 62-a-maltosylmaltose (GlcP (α1→44) Glcp (α1→6) GlcP (α1→4) Glc) . Their optimum pH and temperature were almost similar, but pH and thermal stability of extracellular enzyme were better than those of cell-bound enzyme. Their molecular weight and isoelectric point were different, i, e., 62, 000 and 4.8 (cell-bound enzyme), and 74, 000 and 4.65 (extracellular enzyme).

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