Methods for reducing the content of nucleic acids in isolated yeast protein were investigated. Isolated yeast protein prepared by acid precipitation of the extracted protein after disintegration by a vibrogen cell mill contained about 10% of nucleic acid. The influence of ionic strength and pH value on the content of nucleic acids in the isolated protein was studied. Ionic strength 2.0 and pH 6-7 gave the most suitable condition for reduction of nucleic acid in the isolated protein. Under the condition, most of nucleic acid remained in the supernatant. The content of nitrogen and nucleic acids of the precipitated protein was 12.5 and 1.6%, respectively.

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In previous papers, we have studied the flow behavior and the flow eqnations of starch pastes by using a capillary tube viscometer. In this paper, we proposed the application of a newly designed float-tubular-type viscometer to stain foods.
The viscometric behavior of mayonnaise 50wt% solution, dressing, tomato juice, tomato mix juice, evaporated milk, milk, skim milk 17wt% solution and tomato puree was observed by using this improved viscometer.
The flow equation was expressed as follow:
γ=(1/K)(g_cτ-g_cτ_y)ⁿ
where γ; shear rate(sec^-1), τ; shear stress(gf/cmcm²), and g_c; gravitational conversion factor(g·cm/g_f·sec²). The flow parameters K, n and τ_y were calculated using a non-linear least square method. The values of K which derived from fixed n and τ_y were expressed by the Andrade equation.

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The emulsifying properties of three kinds of Candida utilis: 1)grown on n-paraffin(NP-yeast), 2)grown on acetic acid(KN-yeast), and 3)grown on sulfite liquor(SL-yeast)were studied in comparison with those of soy eprotin. The emulsion stability(ES)and emulsifying capacity of protein isolates prepared from these yeasts by alkaline extraction were superior to those of soy protein, especially in the slightly acidic region. The ES was in the order of SL-yeast>KN-yeast>NP-yeast>soy protein. These results were presumed to depend mainly on the extent of partial hydrolysis caused during protein preparation. Hydrolysate obtained by direct partial hydrolysis of damaged yeast cells using hydrochloric acid indicated a high ES level in the slightly acidic region regardless of the removal of the insoluble fractions. This simple one-step process was significant from the standpoint of actual food utilization of single-cell proteins.

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With the purpose to save the calyx removing labor of strawberry cv. America for processing, the present study was carried out to search the growing conditions which facilitate detachment of straw-berry fruits from the cayxes, leaving the latters on the peduncles, by a single hand pulling.
The percentage of calyx-free fruits was generally high in early season of harvest, but remarkably decreased in late season.
The percentage of calyx-free fruits was increased both by spraying some kinds of fungicides in early season of harvest and by combined application of gibberellin and potassium phosphate in late season. However even by these treatments, the percentage of calyx-free fruits at the best time of harvest and the total yield of them through the harvest season were not satisfactory in saving the calyx removing labor of growers and canners.

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This study was carried out to search the factors which cause the seasonal change of rate of calyx-free fruits(fruits detached from calyx by single hand harvest)during harvest of strawberry cv. America for processing.
Strawberry plants grown at low temperature(20°/10°C)required longer time for maturation of fruits than those at high temperature(25°/15°C). The percentage of calyx-free fruits was high through the harvesting season and the percentage of hollow fruits was higher than that of the fruits grown at high temperature.
When strawberry plants were grown at high temperature, the percentage of calyx-free fruits was high only on the first day of harvesting and remarkably low at late season of harvesting. At late season, however, a high rate of calyx-free fruits was obtained from the plants foliar-sprayed with gibberellin and nitrogenous, phosphatic and potash fertilizers.
It was found that there were 4 kinds of the fruits in appearance: fruits without calyx, with calyxes and peduncles, with calyxes and the trace of peduncles and with only calyxes. Malformed fruits belonged to the second group. Pectic substances in these fruits were analyzed and the ratio of the amount of those in the pith to that in the flesh attached to the calyx was compared. It was found by series of investigations of the fruits in these 4 groups that the ratio in the fruits which could be picked calyx-free was less. It was suggested that the chemical compositions at the each side of the torn parts of the calyx-free fruits were remarkably different.

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The change of heat with the progress of putrefaction at 30°C were measured by using a twin conductive calorimeter. The heat evolution caused by putrefaction of stirred whole egg and yolk occurred after 4 hours, however, it was not observed within 20 to 24 hours for non-stirred whole egg and stirred egg white. The heat change with putrefaction of a defrosted fish was faster than that of a raw fish. Because the thermogram with putrefaction of milk was good agreed with the growth curve of putrefactive bacteria, the change of heat with putrefaction was found to indicate the true process of putrefaction. When putrefactive bacteria were inoculated on soybean curd (Tofu), the more the number of putrefactive bacteria were, the more rapidly the heat evolution occurred. From these results, it was suggested that the calorimetrical measurement was a useful tool for analysis of putrefaction.

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Commercial dried Shiitake mushroom (Lentinus edodes Sing.) is classified roughly into Haruko, harvested from January to June, and Akiko harvested from July to December. The quantitative difference of RNA-phosphorus between Haruko and Akiko was determined using samples of nine commercial quality grades. The results obtained were as follows: RNA-phosphorus contents(phosphous μmol/g)were 24.2-35.2 in Haruko and 35.1-46.8 in Akiko harvested in 1974, 12.6-35.5 in Haruko and 34.1-45.9 in Akiko harvested in 1975, 24.7-34.3 in Haruko and 16.4-40.1 in Akiko harvested in 1976. Consequently Akiko showed significantly higher RNA-phosphorus content than Haruko. Kuroko, off-grade dried Shiitake mush-room showed less content of RNA-phosphorus than that of commercial grades. No differences were in RNase activities between Haruko and Akiko, and among the commercial grades of dried Shiitake harvested in 1976.

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A simple colorimetric method was used to determine hydroxyproline in food. Dried foods were hydrolyzed in 6N HCl at 110°C for 18hr, and then hydroxyproline in the hydrolyzate was determined after neutralization. Hydroxyproline content in many kinds of foods was determined. In general, animal tissues contained more hydroxyproline than vegetable tissues. Moreover, animal tissues showed higher value of hydroxyproline per protein than vegetable tissues. Significant quantities of hydroxyproline-containing proteins were extracted from animal tissues with 0.6N HCl, but those of vegetable tissues were small amounts.

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Hand-deboned broiler thigh and breast meat with skin and fat, packed under either non-vacuum or vacuum into a polyethylene pouch(thickness, 0.06mm), and stored at 4.5±1.5°C was evaluated for bacterial deterioration. Thigh and breast meat with skin and fat as well as thigh meat without skin and fat, packed under both non-vacuum and vacuum, developed putrefactive odor after 9 days of storage. Thigh and breast meat with skin and fat developed putrefactive odor at lower levels of bacterial count and ammoniac nitrogen than that without skin and fat. In breast meat without skin and fat packed under vacuum, the extension of lag phase in psychrotrophs and coliforms and the increase of generation time in mesophiles and Pseudomonas fluorescens group were observed as compared with that packed under non-vacuum. In broiler meat without skin and fat packed under both nonvacuum or vacuum, the retardation of changes in types of microflora during storage was observed in breast meat as against thigh meat, and no putrefactive odor was detected in breast meat packed under vacuum even after 12 days. However, microflora isolated were only Pseudomonas and Moraxella, and off flavor was found on this meat.

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A method for determination of copper, lead and cadmium in tea by graphite furnace atomic absorption spectrophotometry with higher sensitivity was examined. Samples ashed at 500°C were used throughout the experiment.
When lead and cadmium were analysed, the pre-atomization at high temperature(above 2100°C)was required before each load of the sample solution. The addition of sodium chloride and potassium chloride to a 1N-HCl solution containing 100ppb of lead interfered the determination of lead. And the lead content of the sample solution in 1N-HCl could not be determined either. But that of the sample solution in 1N-HNO₃ could be determined, because the interference was a little compared with that in 1N-HCl. When copper, 1ead and cadmium were extracted by the Iodide-MIBK extraction method, there was no interference with the determination. When the copper, lead and cadmium contents of 54 samples obtained from various producing districts were determined by this method, the means of copper, lead and cadmium were 11.9μg/g, 0.31μg/g, and 0.023μg/g, respectively. The values of lead and cadmium analysed by graphite furnace were slightly low compared with those by atomic absorption spectrophotometry using air-acetylene flame.

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