The changes in the iodine color spectra of sweet potato, potato, tapioca and corn starches during enzymic liquefaction with α-amylase were followed, the effect of the addition of a synthetic absorbent resin being also investigated.
Four types of iodine color spectral change were observed.
The amounts of fatty acids in a liquefied solution of corn starch at various temperatures were determined. Almost all the fatty acids were free at 130°C, and some were bound by amylose at 90°C, 80°C and 70°C, and most of them were bound at 60°C and 50°C.
We think that the temperature at which the fatty acids develop may correspond to the one at which the helical structure of amylose of corn starch collapses.
The composition of free fatty acids in the digest during corn starch liquefaction with α-amylase was also investigated.
Unsaturated fatty acids, which were released after autoclaving of the first liquefied solution, were considered to be used for the formation of an amylose complex and were found to be released from the amylose complex on the second enzymic liquefaction.
It is thought that these unsaturated fatty acids were loosely complexed with the amylose.

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The differences in the action on raw starch of the bacterial β-amylase of strain No. 2718 isolated from soil and soy-bean β-amylase were studied.
The bacterial β-amylase showed good adsorption and higher digestibility of raw starch but the soy-bean enzyme not so much.
The effects of temperature on raw starch digestion by the two β-amylases were as follows; the bacterial β-amylase easily hydrolyzed raw starch below its gelatinization temperature. On the other hand, soy-bean β-amylase hardly hydrolyzed raw starch below its gelatinization temperature.
The hydrolysis of raw starch by bacterial β-amylase was enhanced by pre-treatment of the starch with warm water.

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A disproportionating enzyme (D-enzyme or 4-α-D-Glucanotransferase, EC 2. 4. 1. 25) was purified from malted barley by subjecting a crude extract to ammonium sulfate precipitation, ion exchange chromatography on DEAE-cellulose, gel filtration on Sephadex G-150, hydroxylapatite column adsorption and chromatofocusing successively. This preparation showed a single band on iodine staining for enzymic activity, while three faint protein bands were observed other than the enzymically active main band on polyacrylamide disc-gel electrophoresis. But α-amylase, β-amylase, α-glucosidase and R-enzyme activities were not detected in this purified enzyme preparation.
This enzyme had pH and temperature optima of 6.5 and 45°C, respectively, and was stable within the pH range of 6.5-12.0 at 4°C for 24hr and the temperature range of 25-45°C at pH 6.8 for 10min. It was suggested that this enzyme was a sulfhydryl enzyme, because its enzymic activity was inhibited by p-OHMB. When the enzyme attacked several maltooligosaccharides, it finally produced a series of maltooligosaccharides without maltose, so the existence of “forbidden linkages” in the substrate structures, as to the D-enzyme action, was supported by the above results.
Furthermore, when the enzyme attacked soluble starch with glucose, the iodine color absorbance of the reaction products decreased linearly and maltotriose was produced from soluble starch and glucose. So, it was supposed that the D-enzyme digests higher molecular-weight saccharides, producing a series of maltooligosaccharides from them.

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Starch samples were prepared from the seeds (cereals) of three kinds of Gramineae that grow wild in Japan, Inu-mugi, Bromus catharticus Vahl, Kamoji-gusa, Agropyron tsukushiense Ohwi var. transiens Ohwi and Ma-karasu-mugi, Avena sativa Linn., with 11, 6 and 33% yields, respectively.
These starches were examined as to granular size and shape, contents of phosphorus and protein, X-ray diffraction pattern, iodine coloration, swelling power, solubility, amylogram, digestibility of raw starches by glucoamylase and other properties.
The Inu-mugi and Kamoji-gusa starches comprised mixtures of large and small granules, similar to barley and rye starches. The large Inu-mugi starch granules had an ellipsoidal shape and those of Kamoji-gusa were round. But the Ma-karasu-mugi starch granules were rather small and had angular shapes. These three starches were found to be gelatinized at 86°C and over on 6% amylograms, and in this high gelatinization temperature they are different from the starches of Chikara-shiba and others reported in the previous paper. However, it was observed that most of the properties of the three starches examined were the same as those of the cereal starches on the whole.

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We report the results of some measurements of the density of potato starch granules. The density was determined as the weight of one starch granule divided by its volume. The weight of one granule was determined as follows: (1) the granule size was kept constant through the use of standard sieves; (2) the number of granules in Microslides (by Vitoro Dynamics Inc.) was counted under a microscope; (3) the glucose value was determined by the phenolsulphuric acid method; (4) the starch value was calculated by multiplying the glucose value by 0.9; and (5) the starch value was divided by the number of starch granules. The arithmetic average of these data indicates the weight of one potato starch granule.
Next, the volume of one granule (moisture content: ca. 12%) was calculated using an elipsoidal equation. The diameter (length and breadth) of a granule was determined by means of photomicrographic measurement. The number of glucose residues in one granule was determined as the starch value of one starch granule divided by 2.69×10^-16μg (M) of a glucose residue molecule. The average number of glucose residues in 1nm³ was determined as the number of glucose residues in one starch granule divided by the volume of one starch granule; and the following results were obtained.
(1) In the growth stage of potato starch granules, the density of the granules fell from about 2.0g/cm³ to about 1.1g/cm³.
(2) The starch granules were classified throughout the whole distribution and divided into four classes on the basis of the number of glucose residues in 1nm³ of one starch granule.

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