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Volume 24 (1983)
- Issue 6 Pages 525-
- Issue 5 Pages 447-
- Issue 4 Pages 363-
- Issue 3 Pages 249-
- Issue 2 Pages 113-
- Issue 1 Pages 1-
Volume 24, Issue 4
Displaying 1-12 of 12 articles from this issue
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Kazue TATSUGUCHI, Naoko IKARIYAMA, Tadao WATANABE1983 Volume 24 Issue 4 Pages 363-368_1
Published: August 05, 1983
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSExponentially grown cells of Escherichia coli JE 1011 were heated in pH 7.0, 0.05M phosphate buffer containing magnesium ion (Mg2+) or Mg2+-free buffer. In nutrient broth, the growth of the former cells was 2-3.5 hour faster than that of latter cells. Cells heated at 48°C and 50°C in Mg2+-free buffer gradually became unable to form colonies on deoxycholate agar medium (DOC). Cells heated at 48°C completely recovered from the damage and formed colonies on DOC upon the addition of Mg2+ to the buffer, but cells heated at 50°C showed only slight recovery. The cells of Escherichia coli JE 1011 also lost the ability to form colonies on DOC upon ethylenediaminetetraacetate treatment. NS mutants (NS1-NS6), which are outer membrane mutants derived from JE 1011, could not grow on DOC. These results suggest that cells with substantial outer membrane damage are unable to form colonies on DOC. The release of cellular materials during heating was suppressed by Mg2+. Mg2+ also protected heat-damaged cells from the anti-microbial action of p-hydroxybenzoic acid esters, except for the butyl ester in the case of cells heated at 50°C. From these results, we suggest that the protective effects of Mg2+ against heat-damage resulted from some reinforcement of the membrane structure by Mg2+, but these effects did not extend to the severe functional and structural damage caused by heating at higher temperature. Thus, p-hydroxybenzoic acid esters can show effective antimicrobial action against cells from which Mg2+ has been removed.View full abstractDownload PDF (671K) -
Takashi HASHIZUME, Tsuyoshi YOKOYAMA, Teruo KAMIKI, Yoshiyuki NAKAMURA ...1983 Volume 24 Issue 4 Pages 369-375_1
Published: August 05, 1983
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSFoodstuffs purchased from supermarkets in Wakayama prefecture were classified into 13 groups (Groups I-XIII) according to market basket method. The homogenates of 12 groups excluding Group IV; fats, oils were dried and extracted with methanol using a Soxhlet apparatus. Group IV was extracted with methanol by liquid-liquid extraction. These methanol extracts were subjected to mutagenicity assay against S. typhimurium TA 98 and TA 100 with or without S9 mix by the preincubation method.
It was found that Group X (fish, molluscs, crustaceans) and XI (meat, egg) induced large numbers of His+ revertant colonies with and without S9 mix in S. typhimurium TA 100, and these two groups constituted about 80-90 percent of the total possible intake of net revertant colonies/day.
Studies were also carried out to test the changes of the numbers of revertant colonies caused by nitrite treatment of each group. Groups XI, IX (seasoning, beverages), VII (green vegetables), VIII (root vegetables, seaweed), II (cereal, potato) and V (beans) showed particularly high increases of His+ revertant colonies after nitrite treatment in the absence of S9 mix. The increase of mutagenic activities was generally small in the presence of S9 mix. Total daily intake of “net His+ revertant colonies” with or without S9 mix from nitrite treated foodstuffs was calculated to be 2.5 and 1.7 times those from nitrite-untreated foodstuffs, respectively.View full abstractDownload PDF (802K) -
Determination of Potassium Bromate by Anion Exchange Resin Column Separation Followed by ColorimetryStudies on Potassium Bromate in Foods. IToshio HIDAKA, Tadashi KIRIGAYA, Masaya KAMIJO, Yukio SUZUKI, Taro KAW ...1983 Volume 24 Issue 4 Pages 376-382_1
Published: August 05, 1983
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSA simple analytical method was developed for quantitative determinaion of potassium bromate in bread and fish paste products by anion exchange resin column separation followed by colorimetry.
The principles of the proposed method are as follows. Potassium bromate was extracted with water from samples, absorbed on an Amberlite IRA-47 (acetate form) resin column in 50% acetic acid condition and eluted with 0.05N potassium hydroxide -0.5N potassium acetate solution. The eluate was mixed with o-tolidine and hydrochloric acid as coloring reagents, and the absorbance of the solution was determined at 440nm after 20 minutes. The recoveries were 74-83% from bread and 79-88% from fish paste products. The detection limit was 1μg/g.
The method was applied to the analysis of bread and fish paste products. In 100 samples (bread 10, fish paste products 90), no potassium bromate was detected.View full abstractDownload PDF (747K) -
Studies on Potassium Bromate in Foods. IIToshio HIDAKA, Tadashi KIRIGAYA, Masaya KAMIJO, Yukio SUZUKI, Taro KAW ...1983 Volume 24 Issue 4 Pages 383-389_1
Published: August 05, 1983
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSIn the previous paper, a simple analytical method for potassium bromate in bread and fish paste products was reported. In this paper, the behavior of potassium bromate added to bread and fish paste products during their preparation was investigated.
The results obtained were as follows:
1) The residue level was less than 1ppm when less than 65ppm of potassium bromate was added to flour in the case of bread and when less than 350ppm was added to the ingredients in the case of fish paste products. However, potassium bromate was detectable in the products when more than 100ppm (in the former case) or more than 500ppm (in the latter case) of potassium bromate was added to the ingredients. The smaller the amount of potassium bromate added, the smaller was the residue in the bread and fish paste samples.
2) Potassium bromate decomposition was remarkable when the samples were heated during preparation.
3) When the total bromide was estimated in commercial fish paste products in which potassium bromate was not detectable, we observed products which suggested that about 350ppm of potassium bromate had been added to the ingredients.
The above finding and the result of our experiments suggest that few commercial fish paste products contain significant amounts of potassium bromate.View full abstractDownload PDF (2003K) -
Shigemi OKA, Toshibumi TSUZUKI, Yoshiaki ANDO1983 Volume 24 Issue 4 Pages 390-395_1
Published: August 05, 1983
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSA total of 16 strains of Clostridium perfringens type A (13 strains from the United States, England, and Japan, implicated in food-poisoning outbreaks, and 3 strains from natural sources) have been studied to determine the relationship between heat-resistance and germination properties of spores. The results obtained are summarized as follows:
1) On the basis of spore resistance at 95°C for 30min, these strains were divided into two groups: i) the strains producing heat-sensitive spores (5 food-poisoning strains and 3 strains from natural sources), ii) the strains producing heat-resistant spores (8 food-poisoning strains).
2) Both heated and unheated spores of the strains of the heat-sensitive group were able to germinate completely in medium “A” containing a combination of L-alanine, inosine, and calcium chloride in the presence of carbon dioxide, although they hardly germinated in medium “K” containing potassium chloride and potassium phosphate buffer (pH7.0, 50mM).
3) Heated spores of the strains of the heat-resistant group were able to germinate in both media “A” and “K”, the extent of germination being slightly greater in the latter than in the former. However, little or no germination occurred with unheated spores of the same strains in these media.
Accordingly, there appears to exist a relationship in these 16 strains of C. perfringens between spore heat-resistance and spore germination properties.View full abstractDownload PDF (676K) -
Studies on Mycotoxins in Foods. VKatsuhiko YAMAMOTO, Haruo TSUBOUCHI, Kazuo HISADA, Yoshio SAKABE1983 Volume 24 Issue 4 Pages 396-402_1
Published: August 05, 1983
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSA plan for sampling of retailed grainy peanut and nut products was designed on the basis of the law of binomial distribution to search for lots with aflatoxin (AF) contamination of 0.1% or more in kernel number and to estimate the proportion of contaminated kernels.
In this plan a grainy sample (500-1000g) was divided into several subsamples of equal weight (100-200g) followed by comminution and re-mixture of comminuted subsamples, and AF analyses were performed on the mixed subsamples to estimate the contamination level of the original sample and on each subsample to obtain the proportion of contaminated kernels.
In a 1981-1982 survey of 144 market samples collected in the Nagoya district, 2 lots of peanut samples were AF positive with AF B1 contamination levels of 40.0 and 418ppb; the proportions of contaminated kernels were 0.17 and 0.60%, respectively.View full abstractDownload PDF (815K) -
Kenji TANNO, Masahiko TAKAYAMA, Masakazu IKOMA, Bunichi SAITO, Hiroyas ...1983 Volume 24 Issue 4 Pages 403-407_1
Published: August 05, 1983
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSThe microbicidal effects of iodine-glycin complex solution (IG), which contains potassium tetraglycin triiodide (16.0% as active iodine at final conc.) and phosphoric acid (8.0% at final conc.), were examined on various microbes.
Minimum microbicidal concentrations (as active iodine) of IG, acting within 10min, were 4.0-8.0ppm for Gram-negative bacteria, 3.0-7.0ppm for Gram-positive bacteria, 1800-4000ppm for bacterial spores and 2.0-160ppm for fungi.
The fungicidal effects of IG on Aspergillus niger were compared with those of six kinds of commercial disinfectants. The effects of IG were comparable or superior, and no surviving spores were detected in the solution by the pour-plating culture method when the spores were suspended (ca. 104/ml) in 2000-fold dilution of IG for 10min.View full abstractDownload PDF (451K) -
Effects of Tar Dyes on RNA Synthesis (Part 4)Makoto YOSHIMOTO, Shoji HATANO, Tadao WATANABE1983 Volume 24 Issue 4 Pages 408-410_1
Published: August 05, 1983
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSIncorporation of 3H-UTP into RNA, and protein and RNA contents were measured in nuclear preparations from rats after two doses of Ponceau 3R, Amaranth, or Sunset Yellow FCF (300mg/kg of body weight). The incorporation of UTP was greater in nuclei from both Ponceau 3R- and Amaranth-treated rats than in those from control rats. Furthermore, two doses of Ponceau 3R increased the RNA content in liver nuclei. No significant difference was observed in the protein content of nuclei isolated from rats treated with these azo dyes or not treated. Nuclear preparations from Sunset Yellow FCF-treated rats showed no difference from the control.
These results suggest that Ponceau 3R and Amaranth stimulate in vivo RNA synthesis in rat liver nuclei.View full abstractDownload PDF (362K) -
Takeji CHIKAMOTO, Tomoaki INOUE, Takeshi MAITANI, Motonori FUJIWARA1983 Volume 24 Issue 4 Pages 411-412
Published: August 05, 1983
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSDownload PDF (260K) -
Studies on the Toxic Substances in Infected Cereals (X)Takumi YOSHIZAWA, Hiroko HOSOKAWA1983 Volume 24 Issue 4 Pages 413-415
Published: August 05, 1983
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSDownload PDF (301K) -
Studies on Natural Benzoic Acid in Agricultural Products and Processed Foods. IToshihiro NAGAYAMA, Motohiro NISHIJIMA, Kazuo YASUDA, Kazuo SAITO, His ...1983 Volume 24 Issue 4 Pages 416-422
Published: August 05, 1983
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSDownload PDF (612K) -
Takahiro ODA1983 Volume 24 Issue 4 Pages 423-428
Published: August 05, 1983
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSDownload PDF (2013K)
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