With 2 strains of E. coli and 2 strains of Staph. aureus, experiments were conducted on the factors affecting the germicidal action of furylfuramide (2- (2-furyl) -3- (5-nitro-2-furyl) -acrylamide; FF).
Results obtained may be summarized as follows:
1. Velocity constants (k) for the germicidal action of the drug were measured in the nutrient broth and the phosphate buffer of pH 7.0, results of which are shown in Table 1. Less germicidal activity of FF was noted in the phosphate buffer with an exception of E. coli O-1.
2. The germicidal activity of FF slightly decreased in alkaline pH (8.0) or by adding 1% of glucose to the nutrient broth (Tables 2 and 3).
3. Temperature coefficients (Q₁₀) for the germicidal action of FF, calculated from k values in Table 4, are in the range between 1.2 and 1.8 (within 20° to 40°C).

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In order to examine the correlation between the stability of both Vitamin A and β-carotene in margarine and moisture together with oils used as raw material, margarine were prepared with various amounts of water, coconut oil and cotton seed oil both of which were raw material oils, and then their preservability was examined at 5°C and 25°C for 12 months.
As a result, it was found that the more the moisture content, the worse became the preservability of vitamin A and β-carotene, and especially this tendency was remarkable in the case of storage at 25°C and in the samples containing liquid oil. And those containillg coconut oil showed an increased stability, but, on the contrary, the survival rate of vitamin A and β-carotene markedly decreased with the increase in the amount of cotton seed oil.

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We studied on the determination of the preservatives in foodstuffs by ultraviolet absorption after dialysis pretreatment.
At this experiment five kinds of preservatives were taken up, namely benzoic acid (BA), dehydroacetic acid (DHA), p-hydroxy benzoate (POBE), salicylic acid (SA) and sorbic acid (SOA).
Results obtained were as follows;
1. A correcting formula was useful to remove interferences resulted from foods.
2. Quantitative analysis of the mixture of preservatives are conducted, making use of variations of absorption values that were caused by the reduction with Raney-Nickel and Zinc or the oxidation with either hydrogen peroxide or potassium permanganate.

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The main purpose of the present work was to detect Vibrio parahaemolyticus from river water not mixed with sea water in other area than Nagasaki-city, from river water of which a great number of halophilic bacteria including the vibrio have been isolated in the previous work, in the light of a report that a few attempts to detect the vibrio from river water of other areas basing on the author's report were unsuccessful.
In this work, the samples (river water) were collected from rivers in Sasebo-city (Table 1), and three broth media were employed for enrichment culture of the water samples (Table 2). The isolation of the vibrio were carried out by means of primary or secondary isolation procedures (Fig. 1).
From these experiments, it was shown that the vibrio was isolated from river water in Sasebo-city as was in Nagasaki-city. This indicated that the isolation of the vibrio from city river water might not be unusual. The comparative results by the three broth media revealed that media containing ethylviolet or super teepol, which have been recognized to be highly effective as selective substances for sea water sample, were either incomplete or inhibitory for the isolation of halophilic bacteria including the vibrio from river water samples (Tables 3 and 4). It was also noted that the bacteria of biotype 2 and bacteria closely related to biotype 1 were isolated by means of secondary isolation procedure from their parent cultures which were obtained by primary isolation procedure and could grow in NaCl-not-containing peptone water (Table 5). The latter bacteria are placed in the V. parahaemolyticus group in the present paper. It is interesting that all of these bacteria indicated hemolytic activity by the method of Kato et al.

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A Colorimetric method, using p-nitrobenzaldehyde and o-dinitrobenzene, combined with the diffusion analysis was established for the determination of cyanide in food.
After the addition of 0.4ml of the absorbing reagent (0.15N KOH) into the inner chamber and then 1-2ml of sample solution (distillate containing 0-150ng CN) and 2ml of 10% H₂SO₄ solution into the outer, the standard unit was allowed to stand for 3 hours at 30-35°C. The content of the inner chamber was treated with chromogenic reagent (0.25ml of 0.1M p-nitrobenzaldehyde methylcellosolve solution and 0.25ml of 0.1M o-dinitrobenzene methylcellosolve solution) and allowed to stand for 30 minutes at room temperature.
After diluting the colored solution with 5ml of methylcellosolve, the absorbance at 560mμ of the solution was measured.
The content of cyanide (CN):
0-464ppm (42 samples) for Beans.
0.014-129ppm (14 samples) for Apricot kernel.
0.008-0.018ppm (3 samples) for Corn.
0-0.013ppm (5 samples) for Tapioca.
38.2-44.5ppm (4 samples) for Chips of Cassava root.
0-3.4ppm (15 samples) for Fruit wine.
0 (10 samples) for “Sake”, Whisky and Brandy.

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Antibiotic effect of Nisin and Tylosin on 78 sporeforming bacteria (53 Bacilli and 25 Clostridia) and 24 non-sporeforming bacteria (5 Lactobacilli, 6 Staphylococci, 6 Escherichia, 4 Aerobactor and 3 Micrococci) were investigated.
Thermophilic spores bearing rods such as B. stearothermophilus, B. coagulans, Cl. nigrificans and Cl. thermosaccharolyticum were more effectively inhibited with Nisin than such mesophilic species as B. subtilis and B. cereus. Similar results were obtained with Tylosin. However, anaerobic spoilage bacteria (Clostridia) were more sensitive to Tylosin. Most of non-spore formers were little or not inhibited with Nisin and Tylosin.

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The content of mercury was determined in “Sake”, rice for “Sake” production, “Sake” cake etc. by means of dithizone method.
Results obtained are summarized as follows:
1. The content of memcury: Below 0.02ppm (11 samples) for “Sake”. Below 0.10ppm (8 samples) for rice for “Sake” production.
0.05ppm-0.77ppm (6 samples) for “Sake” cake.
Below 0.57ppm (9 samples) for rice bran (white).
0.32-1.55ppm (10 samples) for rice bran (brown).
2. It was found that mercury content in rice for “Sake” production was low and the residual mercury in it was accumulated in the “Sake”, cake.

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The growth rate of psychrophilic and mesophilic bacteria in raw milk stored at low and room temperature was studied.
The results were as follows:
1. The maximum number of psychrophilic bacteria in raw milk stored at 5-7°C reached 10⁸-10⁹per ml after 5-7 days and the time required to reach the maximum count of the bacteria was affected by their initial counts. The similarity of the growth rates was observed for psychrophilic and mesophilic bacteria when stored at 20-25°C.
2. Colony forming percentage of the strains isolated from the culture placed at 5-7°C for 7 days was 54% when maintained at 37°C for 2 days.
The majority of isolated psychrophilic bacteria were gram-negative, catalase-positive rods.

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Gas chromatographic procedure for the determination of sodium cyclamate was studied. According to recent studies, it has been reported that sodium cyclamate reacts with nitrite and produces cyclohexanol, cyclohexanone and cyclohexene. The author's experiment showed that the major product of the reaction was cyclohexyl nitrite, together with some cyclohexanol and slight cyclohexene in the presence of excess nitrite at temp. below 5°C.
Using the blended liquid phase column consisting of DC-550 and DEGS (10% of each) on Gaschrom P (60/80mesh) at 60°C, carrier gas nitrogen (60ml/min) and a flame ionization detector, cyclohexyl nitrite and cyclohexanol were investigated. The results are given in Fig. 1- (C) and 2.
Sodium cyclamate was determined on the basis of the cyclohexyl nitrite. The cyclohexyl nitrite was prepared by treating varying amounts of sodium cyclamate with 5ml of 10% sodium nitrite and 4ml of 10% sulfuric acid in ice water and it was extracted with 10ml of n-hexane containing 0.25 v/v% n-decane as internal standard and then injected to the Shimazu gas chromatograph.
The relation between peak heights of cyclohexyl nitrite and amounts of sodium cyclamate was linear in the range of 20-600mg of the latter, and in this case, cyclohexanol did not appeared. But, when excessive amounts (>800mg) of sodium cyclamate were present, the yield of cyclohexyl nitrite diminished and that of cyclohexanol increased. The minimum limit of detection was approximately 0.1μg as sodium cyclamate.

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[in Japanese]

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