The effects of Amberlite IRA-900 (OH) on sugars was investigated from the standpoint of application of ion-exchange resin to the purification of sugar liquor.
1. Sucrose was adsorbed by the resin according to the Freundlich's isotherm. The adsorption of sucrose in the presence of sodium chloride was diminished remarkably, whereas sucrose gave no effect on the ion exchange capacity for chlorine of the resin. When glucose was given in a sucrose-resin system, the adsorption of both sugars decreased, especially, that of sucrose decreased markedly, although the total adsorption capacity of the resin was little affected. More than 95% of the adsorbed sucrose was recoverd with formic acid, aqueous alkalies or carbon dioxide, whereas only 30% desorption was achieved with water.
2. Glucose was, first of all, adsorbed by the resin, then the adsorbed glucose was isomerized, degradated and changed to coloring matter. Glucose recovery from the glucose-resin system became lower as the contact condition was more severe. Among the degradation or isomerization products, fructose, psicose, mannose (minor) and eight organic acids including lactic and glycolic acids were detected. We supposed that glucose under the treatment with the resin was subjected to similar reactions with those in alkaline solutions.

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Changes in metabolism related to gluconeogenesis during the process of chilling-injury in banana fruit were investigated using L-aspartic acid-¹⁴C (U) and L-serine-¹⁴C (U) solely as a substrate.
In the fruits stored at 6°C for 6 to 9 days, incorporations of radioactivities into the sugar fraction after incubation with labelled amino acids were significantly higher than those of healthy fruit stored at 20°C, especially in the case of serine as a substrate.
During the storage at 20°C after storage at 6°C for 9 days, incorporation of both amino acids into the sugar fraction decreased gradually, while the incorporation into the organic acid fraction rather increased.
A drastic increase in incorporation of serine into ethanol fraction was noted in the chillinginjured fruit at 7 days after the storage at 20°C, and the pulp become to soften. At this time, activities of 3-phosphoglycerate dehydrogenase and serine dehydratase, which were concerned with serine metabolism, were 2 times as high as those of fruit stored at 6°C.
From these results, metabolic pathway in chilling-injured banana fruits during the process of after-ripening was discussed.

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The optical densities of theaflavin, thearubigin and water-soluble oxidized matter in black tea infusion were determined by the procedure ascribed by CASSON after several modifications and applied on the evaluation of the quality of black tea infusion.
The optical density values of theaflavin, thearubigin and also theaflavin plus thearubigin showed high positive correlations with the evaluation of the quality of tea, respectively, while water-soluble oxidized matter showed negative correlation.
Furthermore, it was thought that theaflavin, theaflavin plus thearubigin and water-soluble oxidized matter were likely to compose predominantly color of black tea infusion from the results of multiple regression analysis.
From these results, it was assumed that the rates of the optical density values of theaflavin plus thearubigin and water-soluble oxidized matter in total color of black tea infusion were effective to evaluating and classifying black teas.

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Among the high, middle and low grade black teas, the concentration levels of theaflavin, thearubigin and water-soluble oxidized matter were surveyed by using the photometric method shown in previous paper.
The high grade teas showed high concentration levels of theaflavin and thearubigin, while the reversed result was obtained from the low grade one.
Each adjoining groups between high and middle or middle and low grade teas were discriminated by the discriminant functions made from both values of theaflavin and thearubigin or theaflavin plus thearubigin and water.soluble oxidized matter, respectively.
The distributed areas of the infusion colors of respective three grade teas were fixed by the quality control diagrams made from above-mentioned coupled two variables.

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The sedimentation analysis was based on the opacity transfer velocity of micelle under ultracentrifugal field and photograms were taken with a schlieren optical system on the plate. The sedimentation coefficients determined at 30°C in milk serum were 440 S at pH 6.8 and 570 S at pH 5-8, respectively, at the maxima of the concentration gradient curves. The distribution of sedimentation coefficient at pH 6.8 ranged from 250 to 1500 S. The distribution of micelle size calculated from these results ranged from 850 to 2100 Å in diameter with a most probable value of 1200 Å. The size distribution was calculated also at pH 5.8. The micelle size at pH 5.8 was smaller in diameter by about 10% than at pH 6.8, indicating the shrinkage of micelles with decreasing pH.

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Radical concentrations in rice and wheat grains and their components after irradiation with Co-60 γ-rays were determined in time course by using ESR spectrometry. These samples were irradiated in N₂ and in air at different moisture contents and then stored at different temperatures.
Trapped radical concentration increased linearly with increasing dose up to about 0.5 Mrad and was known to be greatly influenced by moisture content, oxygen and stored temperature, though no marked difference between rice and wheat and their varieties or classes. A main part of the free radicals observed in the grains of low water content is 23G in peak width and disap- peared fairly quickly in air, and which is known to be due to the radicals trapped in the starch of endosperm. On the other hand, the radicals observed in bran (11G) and gluten (12G) were considerably stable both in air and in N₂.
Consequently, it was demonstrated that no appreciable amount of free radicals remained in rice and wheat grains which were irradiated with the dose levels necessary for the insect killing and stored at room temperature in air for several days, and accordingly the ESR measurement of residual free radicals would not be available as a tool to detect the irradiated grains.

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The changes of the antioxidative activities of the browning reaction products between D-xylose and one of the followillg compounds, that is, glycine, L-histidine, L-threonine, L-valine, L-lysine, n-buthylamine, n-hexylamine and octylamine were investigated against the autoxidation of linoleic acid during the storage at 37°C in aqueous system. It was observed that the color intensity and the reducing power for potassium-ferricyanide of the browning reaction products between D-xylose and amines were greatly decreased during the storage and that the absorbance maximum of the product from D-xylose-n-butylamine in UV-spectrum shifted to shorter wave length at the same time. The antioxidative activities of these browning reaction products on linoleic acid decreased along with the storage, especially in D-xylose-n-butylamine system.
On the other hand, the changes of color intensity, the reducing power and the UV-spectrum of the browning reaction products from D-xylose-L-amino acids were less than those from D-xylose-amines and moreover their antioxidative activities did not decreased after the storage for 34 days at 37°C.

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The commercial irradiation to inhibit the sprouting of potatoes was offcially approved in August 1972, in Japan. Now the construction of an industrial radiation facility with large containers is planned to process potatoes. The absorption dose of irradiated potatoes by such facility should be in the range from minimum effective dose to maximum dose of 15 krad.
So the dose distribution in the large container (100×160×130cm) filled with potatoes was measured with Fricke dosimeter. The dose uniformity ratios (D_max/D_min calculated from observed values when the container was reversed at half dose)were 3.00 and 2.47 at the distance of 205 and 398cm from source, respectively. From these results, it seemed that the distance from source to container must be more than 4m to achieve a dose uniformity ratio of 2.50.

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