A laboratory investigation of corn steeping was performed using several kinds of agents (sodium hydrogen sulfite, sodium thiosulfate, sodium hydrosulfite, sodium carbonate, sulfurous acid, sodium hydroxide and sulphuric acid). 1) No difference between steeping at 30°C and 50°C was found in the water absorption during the steeping and in the yield of starch, but the extraction of protein was increased at 50°C as compared with that at 30°C. On steeping at 50°C, the extraction of protein was in the following order: 0.4% sodium hydrogen sulfite > 0.4 % sulfurous acid >0.2 % sulphuric acid > 0.1 % sodium hydroxide. The yield of starch increased in steeping using sodium hydrogen sulfite and sulfurous acid in comparison with sulphuric acid and sodium hydroxide. 2) The protein contents of starches after steeped at 30°C in sodium hydrogen sulfite and sulfurous acid were 0.40.46/0, but those in sodium hydroxide and sulphuric acid were 0.74-0.84%. 3) The temperatures of gelatinization of starches after steeped at 50°C in 0.2% and 0.4%; sodium hydrogen sulfite were lower than the others, and their maximum viscosities were highest in those starches.

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A new method of potato processing adopting slicer in place of disintegrator is shown to account for manufacture of better quality starch, making short work of purification of starch, neutralizing difficult problem of the protein water to a considerable extent, awl not discharging the extracted pulp. Potato processing by slicing whole potatoes into thickness of 0, 25 mm liberates 7073% of starch, and the yield decrease in proportion to thickness of slices. The Brabender curve, IR-spectrum of starches obtained by above method were examined as compared with the starches obtained by the usual method. In slicing potatoes into thin slices, contents of nitrogenous constituents in protein water decrease in proportion to thickness of potato slices.

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Color development depending on reduction of o-dianisidine in the colorimetric determination of glucose by the glucose oxidase-peroxidase method was inhibited by L-tryptophan or DLtryptophan in concentration higher than 0.250.5 mM. Inhibition by L-tryptophan of either glucose oxidase or peroxidase was shown by reduction of 2, 6-dichlorophenol indophenol and oxidation of pyrogallol, respectively. Glucose can be determined chemically by the anthronesulfuric acid method of HANSEN et al. (Am. J. Physiol., 198, 850 (1960)) in the presence of 1020 mM L-tryptophan. The maximum wave length of absorption curves for the reaction mixtures was shifted from 600 nm (without tryptophan) to 530 nm (with tryptophan).

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Uncatalyzed polymerization of methyl methacrylate (MMA) in the system of starch-water or starch-water-carbon tetrachloride was carried out in vacuo sealed tube at 40°C for 5 hrs. As the result, both total conversion (T) and yield of homopolymer (H) showed maximum values at 2 vol.% of CCl₄. Percentage of grafting (P), graft efficiency and percentage of weight increment (W) of corn starch (CS) were markedly diminished by addition of CCl₄. The polymerization of MMA was somewhat hindered by the presence of CS, while it was accelerated by the presence of potato starch (PS) . The (H) value was exclusively increased by addition of the emulsifier. When air was enclosed into the sealed tube and the polymerization was attained, the (P) value, the (W) value and the (H) value were increased by this system compared with vacuo system. Moreover, a small quantity of oxygen in the sealed tube further increased the (P) value. As for the effect of the kind of starch on the (T) value, the PS increased the (T) value more than the CS. The (T) value was increased by a slight amount of cupric salt absorbed on the starch. In this case, the effect of kind of starch on the (T) value showed a similar tendency.

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In order to set measures of waste water control and to improve product yield in noodlemaking, the conditions of noodle-making were assessed in terms of material loss in boiling, and the following results were obtained 1) Material loss in boiling is greater when gluten content of flour is smaller or when starch granules are damaged. 2) Higher moisture content and salt content of fresh noodle minimize boiling time and thus decrease material loss in boiling. 3) It was estimated that appropriate dough sheeting stimulates the formation of gluten net wark and decreases material loss in boiling. 4) Thinner fresh noodle gives less material loss in the same boiling condition (water content of boiled noodle) 5) Use of round cutting roll appeared to give slightly less material loss in boiling than square cutting roll. 6) Mature dough sheet gives slightly greater material loss in boiling.

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Starch granules were isolated from the endosperm of barley at stages of germination and the apparent changes of granules resulting by the action of degradative enzymes were followed by the use of a scanning electron microscope. Also, the starch granules from ungerminated barley were subjected to the action of the crude enzyme extract from germinated barley, and the changes occurring in vivo and in vitro were compared. After about 2 days of germination, in parallel with the development of a-amylase activity in the endosperm, there appeared circular pits randomly distributed over the surface of large granules with the exception of the equatorial region of the granules where pits appeared preferentially. After about 3 or 4 days of germination, small starch granules disappeared, no pits were apparent on the surface of small granules during this stage. With the progress of germination, the erosion progressed through the layers towards the interior, and at the same time, the erosion progressed laterally, making apparent the layer structure of the inner architectures of the granule . The inner part of the granule was digested preferentially, while the outer layers resisted to the enzymic attack. These observations were discussed with special reference to the structure of starch granules .

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Changes of the endosperm of barley during germination were examined with the scanning electron microscope (SEM). (1) In the endosperm of ungerminated barley, large starch granules, surrounded by small granules, were embedded in amorphous cementing materials. (2) A mild erosion which might be due to the action of starch degradative enzymes was visible on the surface of some starch granules in the ungerminated barley endosperm. It is postulated that the reserve starch in the endosperm is subjected to degradation even in the process of ripening. (3) At the early stage of germination, the cementing materials embedding the starch granules disappeared and starch granules were free from the coat materials, which causally results in the facilitation of the enzymic attack of starch granules. (4) Large granules often show the equatorial grooves, which are the site of preferential attack by degradative enzymes. (5) Small granules disappeared after 3 or 4 days of germination. Small granules with pits on their surfaces have never been observed. Thus, the degradative pattern of small grannules might be quite different from that of large granules.

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The surface of starch granules, which was coated rather thickly with carbon and gold and then kept in high humidity, showed some cracks in the scanning electron micrographs (Fig . 1). A weak electron beam caused the cracks on the surface of the coated starch granules (Fig . 2), but the greater the intensity of the electron beam (over 15 kV), the more severe the cracks on the exposed surface (Fig. 3). To obtain a high magnification, it is necessary to use a high electron beam intensity, for example 20-25 kV, which causally resulted in the appearance of the protuberances (Fig. 4) or indentations (Fig. 5), giving a pockmarked pattern on the surface of starch granules, especially when the granules were coated thinly. The cracks can be reproduced intentionally by keeping the coated granules in high humidity (over 90% RH). When the coated starch granules were kept in high humidity for a long time (2-3 days), the whole surface of the granules became rugose, including the cracks, during scanning in the microscope (Figs. 6 and 7). The observed cracking patterns were not uniform, namely, there were regular patterns like brick-works (Fig. 1), or fitful! patterns like the superficial appearance of a volley-ball (Fig . 8), and in other cases, intricate lines crossed over the surface. The cracks were observed with several kinds of starches (potato, sweet potato, yam, tapioca, corn, barley, broad bean, gingko, etc.), and were more evident with large starch granules having smooth surfaces.

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