By using a nitrogen gas-packing system, salted "Daikon" (Japanese radish) containing 5-6% NaCl could be stored for six months, from December to June, in the atmospheric temperature. However, it begen to putrefy with the accumulation of an excess amount of lactic acid causing acidification when the temperature rose over 20°C. The change in flora of lactic acid bacteria was studied in both the nitrogen gas-packing system and the conventional open system, since the acidification might be caused by the growth of this group bacteria. In the early stage of storage, about 10⁵ cells/ml of unidentified lactobacilli were found in both systems, then after about 40days, they decreased to below 1×10³ cells/ml probably due to the lowering pH and the atmospheric temperature. In the middle to late stages, Lactobacillus bavaricus, Lactobacillus curvatus, Lactobacillus corynifcrmis subsp. torquens, Lactobacillus brevis, Lactobacillus plantarum, Lactobacillus coryniformis subsp. coryniformis, and some unidentified lactobacilli were found in both systems. The growth of L. bavaricus, L. breuis, and L. coryniformis which are regarded as undesirable lactobatilli producing hydrogen sulfide, ammonia and slimes were fairly suppressed in the nitrogen gas-packing system as compared with the conventional open system. Namely, in the nitrogen gas-packing system, the number of those lactobacilli was 1/100 of that in the open system and their growth delayed about one month. This phenomenon can explain why salted "Daikon" can be stored for a long period of time in the nitrogen gas-packing system. In the late stages, however, salted "Daikon" tended toward putrefaction even in the nitrogen gas-packing system, causing acidification acompanied with the increase of the cell number of L. brevis, L. coryniformis, and L. plantarum, which reached to about 10⁵-10⁶/ml. It is considered that the development of some means to suppress the growth of those bacteria is the most important for further improvement of the nitrogen gas-packing system.

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A total of 171 strains of Lactobacillus was isolated from a soaked fluid of salted "Daikon" (Japanese radish) stored by a nitrogen gas-packing system and a conve ntionalopen system with low concentration of salt (5-6%). One hundred and nine strains were identified as Lactobacillus curvatus (27 strains), Lactobacillus bavaricus (20 strains), Lactobacillus plantarum (13 strains), Lactobacillus brevis (13 strains), Lactobacillus coryniformis subsp. torquens (10 strains) and Lactobacillus coryniformis subsp. coryniformis (26 strains). The remaining 62 strains could not be identified as any known species, although they were divided into 12 groups in the genus Lactobacillus.

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The Variable Low Pressure Storage (V.L.P.S.) that regulates the different pressures P₁ and P₂ during storage in a chamber possesses advantages on the supply of O₂ gas into the chamber and the exclusion of CO₂ gas from it because of changing inner pressures periodically. Storage tests were done in order to compare V.L.P.S. with ordinary Low Pressure Storage, using cabbage and turnip. The pressure P₁ was set up the 100mmHg, and the other presure P₂ was set up the 300mmHg at these tests. V.L.P.S. was superior to the ordinary Low Pressure Storage in the ratio of weight loss or the appearance of both cabbage and turnip. The V.L.P.S. system did not require a moisture implement because the inlet air to the chamber was saturated instantly with water vapor which was produced by respiration or evaporation from cabbage or turnip.

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Clostridium botultinum spores (a mixture of five type A and five type B strains) were inoculated (1000 spores per ml) into canned liquid teas to see if they germinate, proliferate, or produce toxin during storage. Four kinds of canned tea drinks, i.e., brick-packed black tea (lightly sweetened type and sugar supplemented type), green tea and oolong tea, were incubated anaerobically for 3 months at 30°C after inoculation and the viable countings were made by both the MPN and pouch methods. The viable countings decreased markedly in all tea drinks but green tea. Heat treatment of the inoculated green tea for 30 min at 85°C decreased the viable spores. All viable cells were heat-stable spores. Intraperitoneal injection of these incubates affected no mouse. To identify the effective components, black tea was fractionated into the tannic and non-tannic components. The spores incubated in the tannic component decreased, while those in the non-tannic component did not. The above results show that the tea drinks have a certain C. botulinum spore-killing effect and. the effect is due to the tannic (polyphenolic) components.

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With the purpose of establishing an objective evaluation method for the aroma ofchewing gum, we masticated the trial chewing gums containing each one of 17 single flavors and diffused the volatile flavor compounds into the "Sniff-Pipe" which we originated. And these flavor compounds were estimated at the distance of 1.0, 1.5 and 2.0 meters on the "Sniff-Pipe" by gas chromatographic analysis using the adsorption process of silica gel, and the perception of diffusion was evaluated on discrimination time with sensory odor test. Then the diffusion level of flavor compounds was good reproducibility in the "SniffPipe" at constant 36°C regardless room temperature. And in the result of discrimination time at the fixed distance, the diffusion of chewing gums containing each one of 17 single flavors was approximately grouped into 3 classes according to the difference of diffusion speed. And it was certified that the "Sniff-Pipe" was one of the useful method of measurement for volatile flavor compounds.

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r 20min. The paste, at concentrations ranging from 5 to 20%, changed into a turbid sol after storage at a temperature below 5°C for 3 days. There was a linear relationship between log G' and log C². However, an amylopectin sol formed a hard gel at aconcentration above 20%, and G' increased rapidly in proportion to C¹⁷. Since the almost same values of G' for waxy corn starch were obtained as those for Shiratama mochi cake even at low concentration, it was suggested that amylopectin molecules might contribute to the establishment of hardness in the latter as in the former paste. The formation of hard gel for waxy corn starch depended on period of storage at a low temperature. A hyperbolicrelationship between the setting time and the concentration of waxy corn starch was observed. It was revealed by phase microscopic observation that an increase of turbidity of the paste of waxy corn starch might be due to the development of micro-granules, that a phase-separated networks between the molecules might be involved.

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Florisil-treated peanut oil (10ml) was adsorbed on Whatman No.42 filter papers with or without 10 mmol amino acid (alanine, valine and proline) and then the filter papers were incubated at 50°C for 60 days in the dark. In the presence of these amino acids, browning of peanut oil occurred along with oxidation and its intensity was the strongest with proline. However, no browning took place when only peanut oil was incubated. The iodine value of peanut oil decreased to 32-38 after 60 days, suggesting polymerization and degradation of the oil. And, the ratio of unsaturated fatty acid/total fatty acid of the oil decreased to some extent during incubation. POV and the total carbonyl increased to reach maxima after 30 days. TBA value of peanut oil alone was higher than that with the amino acids during incubation. Browned rancid oil fluoresced at 411-421 nm when excited at 338-343 nm. However, no fluorescence was detected in the rancid oil without the amino acids.

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Near Infrared Spectrophotometer was examined to determine the water content in Oolong-tea and Green-tea, The second derivative NIR spectra of Olong-tea was nearly same as the result found in Greentea, and it showed a strong absorption at 1916 nm assigned to H₂O. Caribration curve of water content in Oolong-tea and Green-tea was made up of adsorbance values and used samples data by the method of loss on drying samples in atomospheric pressure. The water content of unknown tea samples was determined by NIR method with uses of these caribration curve. And these data were compared with the measure by drying method. As a result, with the uses of same kind of tea's caribration curve, the NIR method could compete in terms of accuracy with drying method. But, with the uses of different kind of tea's one, the errors were large.

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Making use of tomatoes and melons, gas components in the low pressure storage chambers were analyzed using a gas sampling implement newly designed and a gas tight syringe. The O₂, CO₂, N₂ and C₂H₄ gases were analyzed by a gas-chromatograph. On the basis of analytical values, CO₂ gas concentrations were calculated for both vegetables. Under the low pressure, the respiratory ratios of tomatoes and melons were 1/30-1/40 and 1/20, respectively, in comparison with those under the normal pressure. In view of these results, it was evident that controlled respiration of the vegetables was effectively realized in the low pressure storage chambers.

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Microbiological assay for vitamin B₁₂ of UHT cow's milk and infant formula was studied using Lactobacillus leichmannii. The optimum conditions were as follows; the wavelength, pre-incubation time, initial cell concentration of test culture and incubation time were 520nm, 5hours, OD₅₂₀=0.01 and 25hours, respectively. This method could decrease the total incubation time from 32-44 to 30hours, and was not necessary in every day's subinoculation because activity of stock culture did not be reduced even in every a month. Recoveries of vitamin B₁₂ were in the range of 95-107%. Repeatability and reproducibility of this method were better than those of other methods.

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Soymilk curd was prepared by using three kinds of proteinases having soymilk-clotting activity (subtilisin, thermolysin and bromelain) as a coagulant followed by lactic acid fermentation. Among these fermented soymilk curds, the curd made with thermolysin showed a little higher moisture content than the others. On the other hand, the curd made with bromelain had a little higher protein recovery and yield than the others. In order to estimate the extent of proteolysis in fermented soymilk curd, analyses were made on electrophoretic patterns, the ratio of water soluble nitrogen to total nitrogen, and free amino acid content. The results of these experiments showed that thermolysin and subtilisin hydolyzed the protein in fermented soymilk curd more than bromelain did. None of the soymilk curd which was fermented for 2 weeks developed bitterness or rancidity. The fermented soymilk curd made with thermolysin was slightly superior in texture (smoothness) to that made with the others. The results of this study suggest that thermolysin, as compared with subtilisin and bromelain, is more suitable for making fermented soymilk curd with respect to proteolysis and texture (smoothness).

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