This study was carried out to clarify softening phenomena of vegetable tissues in Misozuke, and some properties of partially purified enzyme related to maceration of desalted turnip in Miso. The optimum pH and temperature for M-activity (macerating activity on desalted turnip) in the dialyzate of Miso juice were found to be 2.8-3.2 and 40-45°C, respectively. Optimum pH values of PAVR (activity of reduction in viscosity of pectic acid) and PVR (activity of reduction in viscosity of pectin) were observed to be 3.5-4.0 and 4.0-4.5, respectively. PAVR and M-activity in the dialyzed Miso juice showed parallel increase with reaction time at pH 3.3. When the Miso juice was purified partially, activities of PAVR and PVR decreased markedly as compared that of M-activity. Furthermore, microscopic observation of unicells and the increase in uronic acid following maceration suggested that M-activity mainly resulted from the action of pectinolytic enzyme.

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Salts (CaCl₂, CaSO₄) were added to the dialyzate of Miso juice and brined radish root for the purpose of protection of vegetable tissues from softening in Misozuke. Addition of calcium ion in brine of radish root showed protective effect against softening by heating or acid-soaking. Addition of aluminum potassium sulfate was effective for heating, but accelerated the softening by the enzyme reaction or acid-soaking. Calcium ion added to brined radish root combined largely with watersoluble pectin and sodium hexametaphosphate-soluble pectin (pp). When softening was artificially caused by heating at 95°C for 55min or soaking in 3% citric acid, the calcium combined with pp decrease significantly. The preventing effect against M-activity (macerating activity on desaled turnip) owing to the formation of calcium pectate was not observed, but Ca, Zn, Ba, Cu and chlorogenic acid inhibited the M-activity in concentration of 0.01M.

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Methods for suppressing M-activity (macerating activity on desalted turnip) in a dialyzate of Miso juice were investigated by the use of seasoning related compounds, pasteurization and calcium. Softening of radish root tissue in Misozuke appeared to be caused by the activation of macerating enzyme in Miso with the decrease of NaCl concentration, but not by the enzyme in radish root. On the other hand, when softening of brined radish root was artificially caused by enzyme reaction, heating and acid, pectic substance was mainly denatured from hydrochloric acid-soluble pectin to water-soluble pectin. Texture of brined root added with sucrose, glucose or ethanol showed increase in firmness and inhibited M-activity because of osmotic pressure. While an inactivation condition by pasteurization was heating above 60°C for 20 minutes. The M-activity produced by Aspergillus oryzae was strongly inhibited by about 0.5% calcium salts (CaCl₂, CaSO₄).

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The mechanism of drying process of thick foods by microwave energy and flowing air was studied in this work. Piled wet papers (20mm thickness) were used as a food model and they were dried by flowing air with various temperatures, humidities and rates in microwave draft cavity. Their inner layer was maintained at prescribed temperature. throughout drying period by controlling microwave power. The results obtained were as follows. (1) Moisture distribution in the samples in microwave drying process much depends on the temperature difference ΔT between the temperature of their inner layer, T_i and the temperature of the flowing air, T_a (ΔT=T_i-T_a). When ΔT is less than 20°C, drying proceeds under the state where moisture content of inner layer Wi is more than that of outer one, W_o. However, when ΔT is higher than 30°C, it dose under the state where W_o>W_i. And when ΔT is approximately equal to 25°C, drying of the samples iS performed under the state where W_o≈W_i. From these results, it might be suggested that if we choose ΔT of adequate value, any kinds of foods may be dehydrated uniformly. (2) When the temperature of the flowing air is lower than that of the sample, drying rate are decreased in proportion to its flowing rate, since heat transduced from energy of microwave in the sample is removed significantly. (3) Humidity of the flowing air dose not effect so much on drying rate, distribution of moisture and temperature in the samples.

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Aiming at efficient production of bean sprouts having heavier (thick) hypocotyls, intemittent ethylene treatment was investigated. Soybeans, mung beans, and adzuki beans were soaked in 30°C-water for 5 hours and planted on sprouting beds in the dark at 30°C. Water was sprayed for 15 minutes at intervals of 4 hours, and air containing 10, 50, or 100ppm of ethylene was flushed for 60 minutes once every day starting 12 hours after planting. The ethylene treatment showed striking effects on the growth and the quality of bean sprouts. The treatment with 100ppm ethylene resulted in unfavorable effects such as retardation of hypocotyl elongation, hardening and yellowing of hypocotyl, and growth promotion of lateral roots, while it increased weight and vitamin C content most strikingly. With 50ppm of ethylene, elongation and thickening of hypocotyl were properly enhanced, and marked increases of weight and vitamin C content were found as compared with nontreated materials. Yellowing and hardening of hypocotyls and growth promotion of lateral roots occurred by the treatment, but they were not serious problems when harvested at a suitable time. The treatment with 10ppm ethylene showed a similar but inferior effects to that of 50ppm. With the treatment of 50ppm ethylene, cultiVation period was shortened by 2-3 days. Thus the intermittent treatment with 50ppm ethylene seems to be useful for producing efficiently the heavier hypocotyl bean sprouts which are rich in vitamin C.

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The physical nature of Yuba-like films formed on solutions containing soy protein isolate (SPI) and other foodstuffs was examined, and their structure in section was observed with an optical microscope and an electron microscope. Results obtained were as follows: SPI treated with cellulase had about twice as much SH groups as soy milk. Then, we examined the nature of Yuba-like film formed on a SPI solution upon heating with additive foodstuffs such as agar, caragheenan, milk, egg yolk, gelatin, glycerin, ascorbic acid, lard and soybean oil. The films obtained from the mixtures of SPI and glycerin, ascorbic acid, egg white or their mixtures were superior to the other films in transparence, shrinkage, luster, shear and extension ratio. The Yuba film formed on soy milk or the SPI solution consists of two layers: a high textured layer (HTL) and a low textured layer(LTL). But films obtained from SPI and the above-mentioned foodstuffs, especially egg white or glycerin, showed a clear middle textured layer, named MTL, between HTL and LTL. Some of the foodstuffs were found by staining to be accumulated in the MTL; egg yolk was found in MTL by Sudan III, glycerin by methylene blue, and agar by PAS.

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From the view point of manfacturing process of pickles, this study was performed and the results obtained were follows: (1) In the early stage of salting sodium chloride content was low and methoxyl group content of pectic substance was decreased during salting. (2) Using by DEAE-cellulose chromatography, pectic substance from fresh radish root were divided into 8 fractions where P-4 and P-5 peak were the mainfractions. Contents of methoxyl group in these fractions were decreased in the eluting order. In the same way, pectic substance of the salted radish root were divided into 8 fractions, but the main fractions were P-5 and P-6. (3) During salting total pectic substance content in the crude cell wall did not changed, but the portion of hexametaphosphate soluble pectin remarkably decreased and the contents of Ca and Mg also decreased. The contents of Ca and Mg in crude cell wall of salted radish root prepared with crude salt containing Ca and Mg were larger than that prepared with pure sodium chloride and also the ratio of hexametaphosphate soluble pectin in total pectin was higher. From these results, it was presumed tht ratio of hexametaphosphate soluble pectin in total pectin correlated with contents of Ca and Mg in crude cell wall.

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Two halophilic strains of Bacillus B₃ and Bacillus C₁ were isolated from Burmese fish sauce and Chinese fish sauce in Sehgal and Gibbons Complex (SGC) medium with 3M NaCl and in nutrient broth (NB) medium with 2M NaCl respectively. Growth nature and protease formation of two bacteria in different NaCl concentration ranging from 0M to 4M were investigated. Bacteria were cultured in coresponding medium (80ml) with different NaCl concentration at 30°C under reciprocal shaking and 5ml of slurry was taken out every dry and turbidity was measured against a blank. The slurry was centrifuged at ×10000g for 15min to separate the microorganisms and dialyzed with 400 fold water for 24h. Protease activity of dialyzed solution was measued by using 1% casein solution. Both bacteria were found out as capable of growth in medium of 4M NaCl. Maximal growth of Bacillus B₃ was obtained in a medium containing 1-2M NaCl and that of Bacillus C₁ was obtained in 0-3M NaCl. The protease formation of Bacillus B₃ was highest in a medium containing 2M NaCl while that of Bacillus C₁ was highest in a medium containing 1M NaCl. The enzyme produced from Bacillus B₃ had more resistance to NaCl than that produced from Bacillus C₁.

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Accelerated production of fish sauce by adding some halophilic bacteria was studied. Sardines (200g) were cut into 2-3cm pieces, uneviscerated and well mixed with 50g of salt. Bacillus C₁ and Bacillus C₆, isolated from Chinese fish sauce and strain No. 3-19-1, isolated from sand of Kinko Bay were cultured in Sehgal and Gibbons Complex (SGC) medium with 3M NaCl and pH 6.6-6.8. The bacteria were harvested on the day of their maximal growth. Each of the bacterial slurry (12.5ml) was added to the mixture of fish pieces and salt and put into glass jar. To the control without bacteria, 12.5ml of solution containing NaCl and MgSO₄, the concent-rations of which were identical with the cultural medium was added. Progress in proteolysis of fish sauce was investigated by determining pH, total soluble nitrogen content, amino-type nitrogen content and volatile basic nitrogen content of fish sauce throughout the fermentation process. Bacillus C₁ showed remarkable effect on accelerating the process. The liquefaction step could be finishedwithin 3 months. Ripening at various conditions was investigated and it was observed that volatile organic acids appeared within one month in the sample ripened at 30°C under reciprocal shaking. Free amino acids of fish samples were determined and it was recognized that there was no great difference in free amino acid profile of control and that of bacteria-added samples.

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Six kinds of reductone were fractionated by high-performance liquid ckromatography (HPLC) using a SAX-801 Yanaco column and eluting with 0.1M NaNO₃. Detection was accomplished by absorption at 260nm. By this method, 3-hydroxy-2-pyrone (HP) and 3, 4-dihydroxy-5-methyltetron (MDT) were separated from the solution of degradation products of L-ascorbic acid (ASA). The time required for HPLC analysis was approximately 30min, with detection limits of ca. 5.0×10^-4M for HP and 1.0×10^-4M for MDT.

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Ion exchange chromatography and paper electrophoresis are usually used for the analyses of 5'-IMP and 5'-GMP in foods. However, these methods are complicated owing to the necessity of pre-treatment and concentration. Therefore, the possibility of isotachoelectrophoresis for the determination of the compounds was studied. For the leading electrolyte, 0.02M HCl solution (pH 2.35), for the terminal electrolyte, 0.01M n-caproic acid, and for the spacer ion, 1000ppm citric, lactic and α-ketoglutaric acids were used. By this procedure, the simultaneous determination of 5'-IMP and 5'-GMP was accomplished without any pre-treatment. The pricision (coefficient of variation) for 5'-IMP and 5'-GMP were 5.6% and 6.7%, respectively. The limit of determination for these two compounds was as low as 0.05μg, respectively.

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