Oysters stored at -20°C immediately after husking were used. Samples of oysters were taken at intervals during the thawing process at 5°C for 72 hours to be extracted with perchloric acid. The amounts of nucleotides and the related compounds in thawed oysters were determined by the ion exchange chromatography and enzymatic assay. The rapid increse of the content of 5'-IMP was observed during thawing probably due to the deamination of 5'-AMP in fresh oysters.
It was found that the concentration of IMP is very important as the index of the quality of oyster meats because IMP is the major nucleotide and the flavor enhancing constituent in fresh oysters.
The amount of IMP reached the maximum level (0.28μ mole/g) at 5°C after 6 hours thawing.

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To investigate the changes of nucleic acid related compounds in oysters during frozen storage and thawing enzymes responsible for decomposition of nucleic acid and the relating substances were isolated and purified by using DEAE-cellulose and DEAE-sephadex column techniques. Four phosphomonoesterase fractions (A, B, C, D) with the optimal temperature of 40°C and optimal pH range of 4, 0 or 10, 0 were obtained.
Fraction C also contained activity with the optimal temperature of 40°C and optimal pH range of 3.5.
During frozen storage and thawing of oyster meat 5'-AMP and 5'-IMP seemed to be formed from nucleoside polyphosphate by the actions of PMase and DAase contained in the oyster meat.

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The wheat flours of Canada Western No.1, the strong flour, and Norin No.61, the weak flour, were separated into three components of starch, gluten, and water solubles. The effects of these components on baking qualities were tested by reconstitution method. The results indicated starch and gluten of Canada Western No.1 were superior in qualities to that of Norin No.61. Water solubles from the two samples increased the specific volume to the same extent of the bread effectively.

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Citrus Unshiu juice with various contents of pulp (10 to 25%) were dehydrated by spray drying to form powder. The equilibrium moisture contents were determined by the saturated salt solution-desiccator method at 25°C.
The equilibrium moisture contents of the spray-dried Citrus Unshiu juice decreased at low relative humidity, whereas sharp increase was seen at high relative humidity. The equilibrium moisture contents of the powder became larger with decreasing the contents of pulp.
As the relative humidity increased, the powder required longer period to reach the equilibrium moisture contents.
The unilayer adsorption water (4.8 to 6.1%) and adsorption area (171 to 220mm²/g) of the powder became larger with decreasing the contents of pulp.
Isosteric differential heat of adsorption of the powder was 12.2Kcal/mol at low equilibrium moisture contents.

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The water-insoluble naringinase was obtained by linking the native naringinase to DEAEcellulose at pH6.0 with little loss in activity. This insoluble naringinase was compared with the native naringinase to obtain following results,
(1) The optimum pH(4.5) of the insoluble naringinase was not changed but the activity was strengthened at acid pH.
(2) The optimum temperature was shifted from 55°C to 50°C, while the peak of the temperature-activity curve was broader than the native.
(3) The heat stability was strengthened, especially at 60°C.
(4) The preservability was improved very much.

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We have investigated the time-temperature tolerance of various fresh fruits and vegetables during low temperature storage at above freezing temperature in relation to their marketing qualities. This report describes the effects of various temperatures and the fluctuation on the quality of spinach and celery during the storage.
1. It was recognized that freshness, leaf color and ascorbic acid content of spinach were strongly influenced by storage temperatures. The period of keeping marketing quality of stored spinach was about 35 days at 1°C, about 15 days at 6°C, and about 3 days at 20°C. The fluctuation of the temperature during storage accerated the deterioration of the quality, and it depended on the maximum temperature of the fluctuation. Ascorbic acid content of stored spinach decreased rapidly at 20°C but decreased gradually at 6°C and 1°C, The fluctuation of the temperature during storage resulted in a rapid decrease of ascorbic acid.
2. In order to keep freshness and higher content of reducing sugar in stored celery, the constant low temperature of 1°C was required immediately from the harvest day. The good quality was kept for 7 weeks at 1°C, for about 25 days at 6°C and for about 5 days at 20°C. The patterns of gas chromatogram of the volatile compounds of celery were significantly different between 20°C or 6°C-treatment and 1°C-treatment.
3. Thus, it was shown that for the keeping quality of spinach and celery they should be kept at nearly 1°C immediately after harvest and during the subsequent storage.

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Onion bulbs of unirradiated and irradiated with 4.2 and 8.1 Krad by 60Co gamma rays were stored at 4° and 10°C for five months, and the relationship between the sprouting and the amounts of di-n-propyl disulfide (DPDS) developed from the sliced onions was investigated. The amount of DPDS increased apparently along with the sprouting. The sprout inhibition with the irradiation was appeared to suppress the development of DPDS.

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