Food Hygiene and Safety Science (Shokuhin Eiseigaku Zasshi)
Online ISSN : 1882-1006
Print ISSN : 0015-6426
ISSN-L : 0015-6426
Volume 14 , Issue 1
Showing 1-16 articles out of 16 articles from the selected issue
  • Reference to Microbiological and Chemical Contamination and its Prevention
    Toshitaka NAKAE
    1973 Volume 14 Issue 1 Pages 1-17
    Published: February 05, 1973
    Released: March 01, 2010
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  • Norihide NOSE, Susumu KOBAYASHI, Kazuhiro KIMURA, Yoshinori KIKUCHI
    1973 Volume 14 Issue 1 Pages 18-24
    Published: February 05, 1973
    Released: March 01, 2010
    Polychlorinated biphenyls (PCB) were determined after being converted to biphenyl by dechlorination. Sodium hydro-bis- (2-methoxy ethoxy) aluminate (RDB) was used for dechlorination of PCB. Outline of the procedure is as follows.
    The mixture of hexane extract from the sample and toluene solution of RDB was refluxed on a boiling water bath for 1 hour in 50ml centrifuge tube attached to a reflux condenser with ground glass joint. After cooling the mixture, unreacted RDB was decomposed with distilled water by cooling and the mixture was neutralized with hydrochloric acid. The content in the centrifuge tube was shaken for 30 seconds, then was centrifuged for 5 minutes. The content was decanted into a graduated cylinder to measure the amount of hexane. Liberated biphenyl in hexane was determined by the gas chromatography equipped with flame ionization detector.
    The lower limit of the biphenyl concentration identified was 0.3ppm.
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  • Junichi KURISAKI, Kenji SASAGO, Tomokichi TSUGO, Kunio YAMAUCHI
    1973 Volume 14 Issue 1 Pages 25-30
    Published: February 05, 1973
    Released: March 01, 2010
    Benzoic acid, one of the synthetic preservatives, was detected in cheese as a natural product, and identified using gas chromatograph and a combined gas chromatograph-mass spectrometer. A method for measuring benzoic acid content of cheese was investigated. This method is based on ether extract, cleaning up with acid-treated Florisil column chromatography and gas chromatographic analysis. The recovery was 96.4%.
    The amounts of benzoic acid in 25 samples of cheese were determined. The values ranged from 1.6 to 40.6μg/g of cheese. Not so significant differences were found in benzoic acid content between cheese varieties, domestic and imported. From the viewpoint of food hygiene, these amounts might be acceptable, but benzoic acid produced in cheese may contribute to the antimicrobial activity of cheese.
    The precursors of benzoic acid in cheese were investigated by manufacturing the yeastripened cheese, to which hippuric acid, phenylalanine, tyrosine, phenylalanine-U-14C, or tyrosine-U-14C was added. It was suggested that the greater amount of benzoic acid in cheese might be produced from hippuric acid in milk by bacteria in the early stage of ripening and a small part might be derived from phenylalanine. Tyrosine was not converted into benzoic acid.
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  • I. Modified Cu-dithiocarbamate Colorimetric Method for the Determination of Secondary Amines
    Toshiharu KAWABATA, Tohru ISHIBASHI, Masamichi NAKAMURA
    1973 Volume 14 Issue 1 Pages 31-36
    Published: February 05, 1973
    Released: July 27, 2010
    A modified Cu-dithiocarbamate method was devised for determining secondary amines in foods. Procedure is as follows: A 5ml of trichloroacetic acid (TCA) extract of food sample and 1ml of 2% TCA solution are taken into a 50ml separatory funnel to which are added 10ml of 5% CS2-chloroform and 0.2ml of the alkali reagent, and the funnel is shaken vigorously by a mechanical shaker for 2 minutes. Then 1ml of the Cu-reagent is added to the funnel and it is shaken vigorously for 1 minute. Immediately after shaking, 1ml of 30% acetic acid solution is added to the reaction mixture, then the funnel is shaken for a few seconds. The lower layer (CHCl3) in the funnel is separated in a test tube to which 0.4g of anhydrous Na2SO4 is added to remove moisture. The color intensity of the CHCl3 solution is determined at 435mμ by a spectrophotometer. Similar test is conducted with the test solution containing 5μg of standard dimethylamine-nitrogen (DMA-N) (1ml of 5μg/ml of DMA-N is added to 5ml of the test solution). The concentration of secondary amines may be calculated by the following equation:
    where, C; concentration of secondary amine-N (DMA-N equivalent, p. p. m.)
    A1; absorbance obtained with a test solution
    A2; absorbance obtained with the test solution containing 5μg of standard DMA-N
    *; amount of standard DMA-N added (5μg)
    The recovery of DMA-N added to food samples is approximately 97%.
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  • II. Differentiation and Quantification of Nitrosated Secondary Amines by Gas-Liquid Chromatography
    Toshiharu KAWABATA, Tohru ISHIBASHI, Masami MATSUI
    1973 Volume 14 Issue 1 Pages 37-44
    Published: February 05, 1973
    Released: July 27, 2010
    Volatile secondary amines in foods can be differentiated and determined as follows: The secondary amines in a food sample are extracted with trichloroacetic acid, the extract is distilled in vacuum under alkaline condition; the amines in the distillate are nitrosated with sodium nitrite in acid solution (at 30°C for 30min.); the nitrosamines formed are extracted with methylene chloride, being concentrated and subjected to determination by a gas chromatograph with a modified thermoionic detector.
    Two different types of columns, Chromosorb W-25% PEG 6, 000, and Chromosorb W-24% Versamid 900, both of which being packed in coiled glass tubings (3×2, 500mm), are employed_for gas-liquid chromatography, and the former column is suitable for the quantitative analysis of nitrosated secondary amines.
    The recoveries of secondary amines added to foods were found more than 95%. The presence of primary and tertiary amines in foods at natural level did not interfere the analysis significantly. The application of the procedure to the analysis of salted Alaska pollack and fish ham samples disclosed that dimethylamine was the main component among the secondary amines in the materials so far tested, and a trace amount of diethylamine was also detected.
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  • Masamichi TOYOMIZU, Ricardo INOUYE, Takashi NAKAMURA
    1973 Volume 14 Issue 1 Pages 45-50
    Published: February 05, 1973
    Released: July 27, 2010
    As it appears that gel filtration promises to be a powerful tool in the study on the discoloration of oxidized lipid, the discolored lipid and the oxidized lipid were subjected to gel filtration on Sephadex LH-20 or Bio-Beads S-X 3 with CHCl3: MeOH (2: 1) or benzene as a solvent.
    In the discoloration of oxidized linolenate by trimethylamine-blowing, the discoloration proceeded with the time of oxidation and was accompanied by a notable decrease in active groups such as peroxide and carbonyl. Most of the discolored products were fractionated into the largest molecular size fraction. Furthermore, the spot test with trimethylamine showed that the larger the molecular size of oxidized linolenate fraction, the stronger was the discoloration.
    On the basis of these results, the authors concluded that the discolored product was the large molecular size molecule produced by the reaction between the oxidized and polymerized lipid and trimethylamine.
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  • Shigenobu WATANABE, Yoshihisa SAITO, Humiko IWASAKI, Yutaka WADA, Take ...
    1973 Volume 14 Issue 1 Pages 51-55
    Published: February 05, 1973
    Released: March 01, 2010
    It was studied in this report on the determination of secondary amines in food, by use of the modified fluorometric method reported by Tamura being accompanied with favorable results.
    The principal of the method is as follows.
    1) Amines were separated by steam-distillation in alkaline solution.
    2) Amines reacted with 1-dimethylaminonaphtalene-5-sulfonyl chloride (Dansylchloride) to produce sulfonamide in weak alkaline medium.
    3) After standing for 3 hours, the products were separated on the T.L.C. (Adsorbent; Wakogel: Avicel=3: 1 Solvent; 0.5M Boric Acid soln. Developing Solvent; Ethyl Ether: Petro. Ether=2: 1).
    4) After the development, the part containing dimethylamine was scraped and extracted with methanol.
    5) Determine the intensity of fluorescence and calculate.
    The results are as follow.
    1) Recovery values were 70-105%
    2) A linear calibration curve was obtained in the range from 0.2 to 1.0μg for dimethylamine.
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  • Naoko NAKANO, Takehiko KUNIMOTO, Kageaki AIBARA
    1973 Volume 14 Issue 1 Pages 56-64
    Published: February 05, 1973
    Released: March 01, 2010
    To establish the method for detection of mycotoxins from grains contaminated by Fusarium, the recovery study of fusarenon-X (Fu-X) or diacetoxyscirpenol (DAS) added to rice powder was carried out. Fu-X or DAS was extracted from hexane-washed rice powder with methanol-NaCl and transfered into chloroform by liquid-liquid partition, and the extracts were analyzed by silica gel TLC. The toxins were detected on a thin-layer chromatogram by spraying with sulfuric acid or p-anisaldehyde and determined quantitatively by densitometry in the range of 0.25-2μg/spot. Quantitative analysis of DAS were also studied by the fluorometric method with the detection limit of 0.05μg per spot. The same samples extracted were assayed biologically using the inhibitory activity of these mycotoxins on the growth of mouse leukemia cells in vitro. The limit of determination ranged 0.04-0.15μg and 0.003-0.01μg for Fu-X and DAS, respectively.
    Recovery of added Fu-X and DAS calculated from these two assay methods averaged approximately 85%.
    These results suggest that the combination of the chemical and biological assay method is very effective for the examination of scirpene mycotoxins.
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  • Shigeo MURAKOSHI, Toshichika OHTOMO, Hiroshi KURATA
    1973 Volume 14 Issue 1 Pages 65-68
    Published: February 05, 1973
    Released: March 01, 2010
    Toxic effects of nine representative mycotoxins to silkworm larvae have been determined by feeding trial. The 2nd and 4th instar of the larvae were fed ad libitum with artificial diet containing different concentrations of the crystalline mycotoxins for ten days. The larvae (mostly 4th instar) were highly susceptible to aflatoxin B1, G1, and ochratoxin A, and were relatively susceptible to sterigmatocystin, diacetoxyscirpenol and β-nitropropionic acid and were less to kojic acid, patulin and penicillic acid. On the eighth day after the beginning of feeding, the larvae fed on 1ppm diet of aflatoxin B1 indicated about 60% of the mortality. It was a noticeable finding that apparently reduction of number of molting of the larvae occurred at the high concentration of kojic acid administered and, in some cases of aflatoxin G1 administration, specific gross-findings which appeared in some part of the segments of the larvae were recognized as blackend and marked hyperplasic changes. Such susceptibility of larvae to aflatoxins and ochratoxin A appeared sufficient to warrant further investigation into the use of larvae as an agent for bioassay.
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  • Yoshihito OMORI, Akira TAKANAKA, Satoru TANAKA, Yoshio Ikeda, Tsuyoshi ...
    1973 Volume 14 Issue 1 Pages 69-74
    Published: February 05, 1973
    Released: March 01, 2010
    Vomiting and diarrhoea occurred in cats given a 10ml per kilogram dose of canned orange juice sample containing high concentration of tin (452ppm), which also developed intoxications in man. Increase of tin concentration by condensation of the sample resulted in an acceleration of onset of toxic manifestations, however, adjustment of pH value to neutral range appeared to have little effect on the development of gastro-intestinal disorders. Presence of tin as complex with citrate in the sample was suspected and the tin complex prepared from stannic chloride and sodium citrate was given to cats as aqueous solution at various doses. Administration of the complex with doses above 9mg tin per kilogram developed toxic effects in every animal tested. Toxic effects of the juice sample disappeared after removal of tin by hydrogen sulfide treatment, but symptoms appeared again following the addition of as much tin to the treated sample as pretreatment level. Thus high concentration of tin in orange juice was suspected to be a cause of intoxication.
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    1973 Volume 14 Issue 1 Pages 75-80
    Published: February 05, 1973
    Released: March 01, 2010
    Effect of short term administration of dibutylhydroxytoluene (BHT) on lipids and drug metabolizing enzyme system of liver in female rats were investigated.
    1) BHT administration caused liver enlargement and the increase of cholesterol in microsomes and mitochondria, and that of phospholipid in microsomes, but no change in serum cholesterol, liver glycogen and triglyceride contents.
    2) BHT administration did not change the percentage composition of phospholipids. However, BHT administration increased the percentage of stearic acid in mitochondria phosphatidyl ethanolamine and phosphatidyl choline fractions, while it decreased that of unsaturated fatty acid such as arachidonic acid.
    3) The activity of aminopyrine demethylase, the contents of cytochrome P-450 and b5, and the spectral difference of aniline binding increased significantly by the BHT administration.
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  • Differentiating Properties of the Five Groups, Pseudomonas I/II, III/IV-NH, III/IV-H, Vibrio and Moraxella
    Masayo OKUZUMI, Susumu HORIE, Masayuki KIMURA, Masamitsu AKAHORI, Masa ...
    1973 Volume 14 Issue 1 Pages 81-89
    Published: February 05, 1973
    Released: March 01, 2010
    In our preceeding papers, it was reported that almost all of the bacterial strains isolated from fresh, frozen and spoiled sea-fish could be placed in the 6 groups, Pseudomonas I, II, III/IV-NH, III/IV-H, Vibrio, and Moraxella. In the present study, a number of biological properties of 314 isolates, including 33 of Pseudomonas I, 36 of Pseudomonas II, 75 of Pseudomonas III/IV-NH, 77 of Pseudomonas III/IV-H, 60 of Vibrio and 43 of Moraxella, were investigated in the hope of finding differentiating features among these groups. The results obtained are summarized below.
    Although Pseudomonas I had been differentiated from Pseudomonas II basing on the fluorescent pigmentation, in the present work it was shown that there was a great similarity between the general biological properties of Pseudomonas I and II organisms. Accordingly, it was proposed that the two groups should be classified as an identical one, Pseudomonas I/II. The Pseudomonas I/II organisms grew in NaCl absent nutrient agar, but failed to grow in 7% NaCl. The Pseudomonas I/II was characterized with acid production from glucose in only aerobic condition, inability of H2S production and of casein hydrolysis, resistance to 5μg/ml malachite green and 100μg/ml leucomycin. Pseudomonas III/IV-NH also grew in NaCl absent medium and did not in 7% NaCl. This group was distinguished from Pseudomonas III/IV-H with H2S production, nitrate reduction and resistance to 50μg/ml methylene blue. Basing on the several features of Pseudomonas III/IV-NH found in this work it was suggested that the group is identical with Pseudomonas putrefaciens. Pseudomonas III/IV-H was clearly distinguished from Pseudomonas I/II and III/IV-NH with growth response at 0 and 7% NaCl and the other several properties mentioned above. The most important feature, which distinguished Vibrio from the other groups was ability of acid production from glucose in both aerobic and anaerobic conditions. Failure to grow both at 0 and 7% NaCl, ability of nitrate reduction, and sensitivity to 5μg/ml malachite green were also found to be useful for the identification of the Vibrio group. Moraxella was characterized with the stout or coccoid form of the cells, growth ability in both 0 and 7% NaCl media, failure of acid productian from the carbohydrates, sensitivity to 3 I.U. /ml penicillin and 0.1μg/ml ampicillin.
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  • A Problem concerning the Determination of Chloride and Sulfate in Food Coal-Tar Dyes
    Yasuhide TONOGAI, Chieko KAMIYOSHI, Yukio NOMURA
    1973 Volume 14 Issue 1 Pages 90-93
    Published: February 05, 1973
    Released: March 01, 2010
    The problems concerning the determination of chloride and sulfate in food coal-tar dyes by the method of the “Japanese Standards of Food Additives” were pointed out, and following results were obtained.
    1. It is necessary to use the same quality of activated charcoal because of its different ability to adsorb chloride and sulfate.
    2. The official method gave apparently lower results because of the adsorption of chloride and sulfate on activated charcoal.
    3. Accurate results were not given by the official titration method for the determination of sulfate in food dye, because of unreliabe end point.
    Therefore, turbidimetry was proposed for the determination of sulfate in food dye in order to compensate these problems and simplify the official inspection of coal-tar dyes.
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  • Shoji KIMURA, Shihoko TERADA
    1973 Volume 14 Issue 1 Pages 94-99
    Published: February 05, 1973
    Released: July 27, 2010
    A method of quantitative analysis of BHA in food is very complicated and it is very hard to analyze many samples in a few days. We studied a simple method for the quantitative analysis of BHA in food. BHA in food was extracted by hexane-acetonitrile, was separated by thin layer chromatography and was developed with a mixture of 2% 2, 6 dichloroquinone-chlorimide and 2% sodium borate.
    After an hour, the color spot on thin layer chromatogramy was scanned densitometrically by transparent methods. The amount of BHA was estimated from spot areas. The wave-length of filter is 624mμ.
    The recovery of BHA added into food was 80-100%. As the result, this method can be applied to the test of many foods.
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  • Relation of Alkalinity to Recovery in the Determination of Secondary Amines
    1973 Volume 14 Issue 1 Pages 100-104
    Published: February 05, 1973
    Released: March 01, 2010
    In the previous paper, the colorimetric determination method of dimethylamine in foods using alkali-steam distillation was reported. Recently, however, a question was proposed agamst the steam distillation with 10N sodium hydroxide solution, because there were some possibilities of formation of dimethylamine from monomethylamine, trimethylamine or trimethylamine oxide which were contained in foods.
    Comparing the color intensity of dimethylamine, monomethylamine, trimethylamine and trimethylamine oxide after steam distillation with sodium hydroxide, color intensity of monomethylamine, trimethylamine and trimethylamine oxide were much less than that of dimethylamine, and in the case of dimethylamine, its recovery by the same procedure was between 98-102%. And also, by the addition of 500ppm of trimethylamine oxide into the fish meat slurry followed by alkali-steam distillation, the changes of the values did not exceed 5% compared with the control. From the results of the experiments, we could not find any disturbance in the process of the determination.
    A proposed method in which magnesium oxide is used instead of 10N sodium hydroxide solution was also tested, but the recovery of dimethylamine in the proposed method was below 10%.
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  • 1973 Volume 14 Issue 1 Pages 135
    Published: 1973
    Released: March 01, 2010
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