The Bartlett pears at the stages of pre-climacteric and climacteric-onset were irradiated at 250-1000 Krad with gamma rays and stored at 20°C. The yellowing of irradiated pears was delayed and high doses of irradiation (above 500 Krad) prevented normal coloring; the 500 Krad-fruits became only yellowish green and the 1000 Krad-fruits did not develop yellowish color. The organoleptic evaluation showed that the acceptability of the irradiated fruits lowered with high dose. Irradiation caused the softening of the tissue immediately after irradiation but the subsequent change was smaller in irradiated fruits than that in unirradiated ones. The decreasing rates of protopectin and water soluble pectin during storage were slower in the irradiated fruits than that in unirradiated ones. Particularly, the flesh of the 1000 Krad-fruits was mealy and atypical. The activities of pectin methylesterase and polygalacturonase during ripening were lower in the 1000 Krad fruits than in control sample.
The characteristic flavor of pears was not given by the fruits which were irradiated at the doses of 500 Krad and 1000 Krad, while in the ripe fruits of 250 Krad-samples the flavor was produced.

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Citrus Unshiu (Japanese mandarin orange "Satsuma") is particulary susceptible to gamma ray irradiation and the adverse effects on flesh flavor and peel appearance were found when fruit was subjected to 50 Krad or more. The work has conducted on shallow irradiation (surface radurization) of Citrus Unshiu by cathode ray to prevent the off-flavor.
Pasteurizing effect on Pen. digitatum inoculated to lower shoulder of fruit was decreased with the time from inoculation to irradiation even the inoculated fruits were stored at 5°C before irradiation. With higher dose softening of peel and the destruction of oil-gland developed during the postirradiation storage and finally the browning of peel appeared. These phenomena depended on the storage time from the harvest to the radiation treatment; deterioration was more severe with the shorter storage after harvest. The browning was accelerated at room temperature but repressed at 5°C storage. The browning was not affected by curing treatment (RH: 75-80%, 5-7°C for 3 weeks) immediately after harvest.
There was same pasteurizing effect by the cathode ray of 1.0 and 0.5 Mev. Pannel test detected the deteriorated flavor change with gamma ray irradiation over 50 Krad and the acceptability was lost over 100 Krad, but the shallow irradiation with 1.0 Mev of cathode ray did not change the flavor acceptability up to 250 Krad.
Analytical data of fruit flesh and juice showed no significant differences between irradiated and non-irradiated spmples after the long term storage. Shallow irradiation of 100-300 Krad appeared to cause some advantages in score of acceptability after the long term storage.

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Factors affecting the microbicidal activity of diethylpyrocarbonate (DEPC) were investigated.
DEPC had relatively strong microbicidal activities against many yeasts, molds (spores) and nonsporeforming bacteria. Temperature coefficient for the disinfection rate of DEPC was twice or more than for its destruction rate.
The microbicidal activity of DEPC increased with the decrease of water activity of the reaction medium adjusted by sodium chloride, glycerol and calcium chloride. On the other hand its microbicidal activity decreased significantly at the presence of citrate, acetate, soluble starch and peptone in the reaction medium, although their effects were influenced with pH value of the reaction medium, concentration ratio to DEPC and other factors.

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Preservating effect of diethylpyrocarbonate (DEPC) by the surface treatment was investigated.
Slime-forming spoilage of wiener sausage was prevented by the dipping treatment with DEPC aqueous solution for two or three times longer than untreated samples at the storage temperature of 10°C or below.
The optimum conditions of dipping treatment were as follows:
Concentration of DEPC 1000ppm
pH 5.0 or below
temperature 30°C or higher
dipping time 5 minutes or below, depending on the dipping temperature
Surface spoilages of wiener sausage, bread and soy bean paste were prevented by DEPC-spray treatment using Freon or LP gas as a diluent gas.

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Rice is deteriorated with storage at high temperature for long period by the oxidation of fat resulting in the production of volatile carbonyl compounds and volatile carboxylic acids such as npropanal, n-hexanal, n-valeric acid and so on. Therefore, it was tried to eliminate the rancid odor in boiling rice by the addition of cystein, cystine, DL-alanine, L-leucine, L-histidine, L-lysine hydrochloride, L-glutamic acid and mono-sodium glutamate. Only L-lysine hydrochloride was effective for this purpose. Hence, the mechanisms of this phenomenon were investigted by gas chromatographic procedure as follows; the dilute aqueous solutions of n-propanal were heated with free Llysine, L-lysine hydrochloride, DL-alanine, L-ornitine, L-arginine and L-lysine hydrochloride containing calcium carbonate, and then, each 10μl of thus heated solutions were injected directly to gas chromatography. The original peak of n-propanal disappeared by the heating with free L-lysine, L-lysine, L-ornitine, L-arginine and L-lysine hydrochloride containing calcium carbonate. On these results, it was able to presume that the elimination of rancid odor in rice was caused by the reaction of ε-amino residue in L-lysine with volatile carbonyl compounds. Volatile carboxylic acids in rancid odor were also changed into non-volatile one with the same mechanisms.

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The reason why the beef tallow floats as many small glitter disks on the surface of beef extract solution whereas it forms a large disk-like substance on the surface of yeast extract solution to which tallow is added was investigated as a problem of surface tension.
In beef extract, remarkable amount of cation colloids was detected by colloid titration following Senjyu's method, but not in yeast extract.
When the cations of beef extract was nutralized with anion colloids, the liquid lost the characteristic property and resembled to the yeast extract in respect to the floatation of tallow. Then the beef extract was fractionated into high molecular cation part, non-ionic high molecuar part and low molecular part employing dialysis and cation exchanger chromatography in order to estimate the surface tension. As the results of these experiments, it was revealed that the surface dispersion of beef tallow is affected by the presence of high molecular cations in the solution on which the tallow solidifies.

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Employing soybean 3-sn-phosphatidylcholine was separated by thin-layer chromatography on silica impregnated with silver nitrate into 4 fractions depending on their degree of unsaturation and these fractions were designated as SBL-1, SBL-2, SBL-3, and SBL-4 according to Rf value. The fatty acid components of the SBL-1 were oleic acid (8.2%) and linoleic acid (46.9%) as unsaturated fatty acids. The fatty acid component of the SBL-2 was linoleic acid (over 93.2%) as unsaturated fatty acid. The fatty acid components of the SBL-3 were linolenic acid (24.0%) and linoleic acid (21.4%) as unsaturated fatty acids. The fatty acid component of the SBL-4 was arachidonic acid (63.8%) as unsaturated fatty acid. On the other hand, the 3-sn-phosphatidylcholine was separated into 9 fractions by adsorption column chromatography on silica impregnated with silver nitrate and these fractions were designated as fraction A, A', B, B', C, C', D, E, F and H. The fatty acid components of these fractions were revealed, while the fraction A corresponded to the SBL-2 and the fraction E corresponded to the SBL-4.

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A method for the qualitative determination of capsaicin and its homologue by means of gaschromatography is described. Capsaicin and its homologue can be also completely converted to trimethylsilyl ethers by the reaction with equivalent amounts of trimethylchlorosilane and hexamethyldisilazane.
Relative retention time data are given for capsaicin homologue and its trimethylsilyl ethers on Silicone GE SF-96 column using hydrogen flame ionization detector.

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