To obtain informations on the interaction between the added polyphosphates and agar, the ash composition of agar which was reproduced from the agar gel containing polyphosphate through the repetition of usual manufacturing process was analyzed. The contents of total and HCl-soluble ash, and soluble P²O⁵ were closely correlated with the amount of added H-polyphosphate^*1, respectively. The highest value of ash increase was equal to 11% of the added polyphosphate for h-agar^*2, and 17% for m-agar^*3. The additives less than 200ppm did not always increase ash contents of the products. Soluble Fe³⁺ was reversely proportional to P₂O₅ in the product. Magnesium showed similar tendencies to ionic iron. Total ash and soluble SO₃ decreased with the prolongation of cooking the agar solution.
*1 H polyphosphate: Commercial sodium polyphosphate consisted of 85% of metaphosphate and 15% of pyrophosphate.
*2 h-agar: Powdered agar of h brand which was processed from the alkali treated seaweeds, Gracilaria species.
*3 m-agar: Mixed agar in powder which was experimentally processed from several kind of seaweeds, Gelidium and Gracilaria species.

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The effects of polyphosphates on agar qualities which were confirmed in two factories manufacturing string- and bar-style agar ("hosokanten" and "kakukanten", respectively) were described. By adding 30-100ppm of polyphosphate in the cooking water for extracting agar from seaweeds, improvement in color of the product was obtained without significant decrease in the strength of agar gel.

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It was found in authors' earlier work that soybean protein curd became easy to be squeezed out by freezing and thawing, and on the other hand, soybean protein dissolved in solution became insoluble also by freezing and thawing. In this paper conditions and mechanism under which soybean protein is denatured by freezing are studied by comparing solubilities of acid precipitated soybean protein before and after freezing. The solubility in dilute sodium hydroxide solution is decreased by freezing and more distinctly by frozen storage at -1--3°C. The decrease of the solubility is much more rapid in the case of heat-denatured soybean protein. From the solubility behaviors of the protein in mercaptoethanol, urea and their mixture solutions before and after frozen storage at -1--3°C, disulfide linked polymers of the protein seem to have formed during this process.

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1. Radiation treatment caused exponential reduction in the hardness of raw carrot at the doses from 0.19 to 3.06Mrad. Regardless of blanching treatment after irradiation, irradiated raw carrotat low doses (0.21 and 0.43Mrad) showed faster dehydration while at higher doses (0.86 and 1.17 Mrad) slower dehydration than non-irradiated carrot. The water absorption of dried carrot was accelerated by irradiation of raw material with increased dose level.
2. The changes of swelling velocity were determined using an apparatus for the measurement of the total volume decrease by rehydration of dried carrot in the water under reduced pressure at 35°C. The decrease in the total volume and weight of absorbed water may indicate that a more greater combination or chemical reaction between water molecules and the micelles takes place in the irradiated dried carrot than in the non-irradiated one. These reactions would cause remarkable decrease of total volume with only a slight acceleration of the swelling of the carrot due to absorbed water.
3. In both raw and dried carrot, the radiation treatment caused the decrease of total pectic substances and protopectin and the slight increase of the pectate and the pectin with the increased dose level.
4. No significant differences in flavor and taste after rehydration were detected in irradiated carrot and at the doses of 0.25 and 1.0 Mrad required only two-thirds and a half of cooking time, respectively, of that necessary for non-irradiated carrot.

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To discuss about the behavior of protein components effected by steaming of defatted meal, the amounts of extractable nitrogen in water (W), 0.076M tris-citrate buffer (pH 8.6) (B), B contaning 0.1M 2-mercaptoethanol (BM), and BM containing 8M urea (BUM), respectively, were detrmined over a wide range of steaming time (100°C, RH 100%), and the extracted protein components were analyzed by starch gel electrophoresis. The amount of extractable nitrogen decreased progressively with the increase of steaming time, and the extraction rate was high in order of BUM, BM, B, and W at each steaming condition examined. The insolubilization of proteins in the meal by steaming was more pronounced in the order of D, A, and C components. By increasing the concentration of urea and guanidine, the amount of extractable nitrogen in the meal steamed for 90min. was increased, and the increase in extracted protein components was detected in order of bands 1 to 4, 7 to 9, 5 to 6, and 10. From these results, the insolubilization of soybean proteins in the steamheated meal was discussed.

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Dinitrophenylation of protein at room temperature was investigated to determine the extent of protein denaturation. DNP-protein derived from denatured protein had an absorption band of DNPNO at 1330-1335cm-1 on the infrared absorption curve besides the specific bands attributed to peptide-bands. The degree of dinitrophenylation expressed by the absorption ratio of DNP-NO to Amide-I was used as an index for the extent of denaturation of the protein. Denaturation of soybean protein was investigated with this method, and the method proved to be less complicated and timeconsuming, and gave more reasonable results than the determination of Nitrogen Solubility Index which is used most frequently for the same purpose. Results on the denaturation of freeze-dried protein were also described.

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The effects of sodium chloride and some oxidizing and reducing agents on α-glucosidase (maltase) in baker's yeast were studied. The maltase, extracted from baker's yeast by mechanical destruction of cells, was separated from invertase by selective adsorption on meta-aluminium hydroxide. Glucose oxjdase was used to assay the enzyme activity.
The activity of maltase was reduced to 50% of the original level by addition of 5% NaCl, while no significant effect was observed on invertase activity. Such effect of sodium chloride on invertase and maltase agrees well with the tendencies found in fermentation of sucrose and maltose. Azodicarbonamide (ADA) and potassium iodate considerably inhibited the maltase activity, while the effect of potassium bromate was not significant. Ascorbic acid, cysteine, and glutathione increased the activity. However, their effects on maltose fermentation were in different tendency from those on maltase; the fermentation was accelerated by the addition of ADA, but was inhibited by cysteine.

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The Karl-Fischer titration method (KF method) employing a mixture of formamide-methanol (2:1) for dissolving sample and the film method employing small bag of high density polyethylene film for drying were applied for moisture determination on caramel and sugar candy. With 25 ml of the solvent, 0.2-0.4g caramel was dissolved at 55-60°C, and then titrated by the KF reagent. In case of sugar candy, dissolving was conducted on 1-2g sample at room temperature. This KF method was rapid, and the relative errors obtained on several samples of caramel and sugar candy were ±0.1% and ±0.02%, respectively. Moisture in these samples was determined with satisfactory accuracy and precision by the film method of drying at 100°C under 20-30mmHg for 2 or 4 hours. The relative error was ±0.05%. The difference in the moisture values obtained with these two methods on the same samples was within 0.1%.

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