To obtain some preliminary informations on the relation of changes in metabolic activity of shikimic acid pathway and mechanism of cold injury in peach fruit, shikimic acid and lignin-like substance contents were investigated on peach fruits during the storage at 0°C for 40 days and afte-ripening at 20 to 23°C for 4 days. The presence of shikimic acid in the flesh was confirmed by paper chromatography, and its content was determined colorimetrically by the method of YOSHIDA and HASEGAWA. Lignin-like substance content was determined by Klason's method. Shikimic acid was decreased with after-ripening after cold storage within 15 days, while it was increased with the after-ripening after the storage of 20 days or more. Lignin-like substance was increased with after-ripening throughout the cold storage period examined, and the response was the greatest at the cold storage of 7 and 10 days. From these results, some changes in metabolic activity of shikimic acid pathway in flesh may be considered to occur during cold storage, and it may have an effect on the function of after-ripening. The relationship between lignin-like substance content and hardness of flesh was not observed.

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The accelerating effect of sorbic acid on the thermal injury of yeast cells was investigated under various conditions. With presence of sorbic acid, thermal destruction of several yeast strains was accelerated to shorten the decimal reduction time to 30% or below of that for control. Although the acceleration at heating treatment was more remarkable at lower pH, it was not affected significantly by other factors, such as heating temperature, concentration of sorbic acid, nutrients, cell age, and recovery methods, under conditions examined.

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To find the threshold dose level at which flavor change could be detected in cooked rice, organoleptic test and measurement of cooking quality were conducted on rice treated with various levels of cathode ray. No significant difference in water absorption, swelling volume, and intensity of iodine-starch coloration of soluble fraction of cooked rice was recognized between control and irradiated samples both immediately and eight months after irradiation up to the dose of 60Krad. Off-flavor developed immediately after the irradiation of 30Krad or more, and the rice irradiated at 60Krad was of disagreeable odor, taste, and appearance. However, after the storage of eight months, no significant difference in such characteristics was found among the irradiated samples. Organoleptic quality change by irradiation of 30Krad became undetectable after storage of four months. By measurement of physical properties of cooked rice with Texturometer, significant negative correlations were found between the dose level and hardness, and gumminess, repectively.

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For prevention of freeze-dried foods from oxidation, a tube filter containing butylhydroxyanisole (BHA) was inserted between the inlet pipe and the drying chamber at vacuum-breaking. Lipid oxidation of pork and a model mixture of carboxymethylcellulose and lard freeze-dried by this procedure was retarded to the extent almost equal to the same materials to which BHA was added with usual method. There was no significant difference in BHA absorption among samples from various locations in the chamber, and in the effect between nitrogen and dried air used as the flashing carrier gas of BHA at vacuum-breaking. Better results were obtained at lower temperature in the chamber as well as slower vacuum-breaking.

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Potentiometric titration with silver nitrate was applied to the determination of chloride in miso and soysauce. The titration with this method conducted on the dilute sample dispersions containing ca 0.35% nitric acid and 0.05% Tween 20 gave results in satisfactory precision and the relative error was 0.1-0.2%, while, Mohr's method constantly gave higher values on the same samples due to titration in excess, and its relative error fluctuated 2.6-6.1% on miso and 1.0-3.6% on soysauce. The loss of chlorine during ignition of miso ranged in 0.5-4.5% and such loss was greater in the samples made from higher ratio of rice. The average loss determined on soysauce was 1.2%.

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Physical properties of noodle-dough and boiled noodle was affected greatly by mixing temperature. Orientation of molecular chains in gluten network in the dough seemed to occur in dough sheeting process.

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Effect of 0.015-0.06% sodium polyacrylate, 0.03-0.3% carboxymethylcellulose, and 0.03-0.06% methylcellulose on the rheological properties of noodle-dough was examined. These additives showed the tendency of increasing maximum stress and relaxation time of the dough, however, the relation between the concentration of the additives and the extent of those changes was not simple.

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Coating with glucose, arabinose, starch, or sodium aspartate was effective to retard the lipid oxidation of freeze-dried pork and a model mixture of CMC and lard, although the process requires refreeze-drying of the foods after dipping them into coating materials solutions. Glucose was most effective among the materials examined.

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Oxidation of L-ascorbic acid to dehydro-L-ascorbic acid by use of silver oxide was conducted in ethanol and in acetone. Excess silver in the reaction mixture was removed by filtration with charcoal to avoid the reduction of formed de hydro-L-ascorbic acid by excess of hydrogen sulfide which has been used for silver removal. With this method, the yield of crystalline dehydro-L-ascorbic acid by the reaction in ethanol was 80%, and in acetone 55%.

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