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Volume 14 (1973)
- Issue 6 Pages 501-
- Issue 5 Pages 403-
- Issue 4 Pages 343-
- Issue 3 Pages 219-
- Issue 2 Pages 137-
- Issue 1 Pages 1-
Volume 14, Issue 3
Displaying 1-10 of 10 articles from this issue
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Some Knowledge on the Soluble Components from Urea Resin TablewareYutaka WADA, Shigenobu WATANABE, Takeo TAKAHASHI1973 Volume 14 Issue 3 Pages 219-228
Published: June 05, 1973
Released on J-STAGE: March 01, 2010
JOURNAL FREE ACCESSThe soluble components migrated from urea resin tablewares which had been used by children for long period have been studied.
In this paper, the authors recognized that formaldehyde dissolved continuously and the concentration varied each time to use. And the formaldehyde translated to the solution from the resin, not only as free form but also as combined form from the surface of tableware with gradual degradation.
Furthermore the appearances of the tablewares were observed by scanning electron micrographs and also they were compared with the amount of migrated formaldehyde. The results examined are as follow.
1) The average amount of formaldehyde migrated from one tableware was 684μg from urea resin and 57μg from melamine resin.
2) The amount of formaldehyde increased after irradiation with sterilizing light.
3) Ammonia, urea and urea-formaldehyde compounds were found in the solution by liquid chromatography method.
4) The urea-formaldehyde compounds run on T. L. C. were identified as monomethylolurea and dimethylolurea.
5) Free formaldehyde and low molecular compounds in resin were evaporated by heating at 100°C for 3 hrs.
6) The amount of soluble components were found to be correlated with the surface condition of tablewares.View full abstractDownload PDF (3976K) -
Katsuhiko YAMAMOTO, Shigetoshi MORISHITA, Shigetaka MORIYAMA1973 Volume 14 Issue 3 Pages 229-233
Published: June 05, 1973
Released on J-STAGE: March 01, 2010
JOURNAL FREE ACCESSRecently, the addition of natural colors has been increasing instead of artificial dyes in commercial food. In the qualitative tests of tar dyes, we used the wollen yarn staining method for the clean up of dyes. By this method, carminic acid, the pigment of cochineal and laccaic acid, coloring matter in resin known as stick lac, produced by lac insect, is caught together with acid tar dyes. In the paper chromatographic identification of the dyes, doubtful spots were shown by the above-mentioned dyes in the chromatogram for amaranth when the solvent system of isoamylalcohol: acetone: water (5: 6: 5, v/v/v) was used. Further, when solvent systems were used, it was difficult to identify which color stuff was laccaic acid or carminic acid because they were mixtures of pigments having analogous chemical structures but different Rf values.
Amaranth has three sulfonyl moieties in the molecule, laccaic acid has two carboxyls while carminic acid has one carboxyl. Therefore, electrophoretic analysis might be useful in the separation of these three color stuffs on a standpoint of negative charge in their molecules. Thus, we attempted the separation and identification of them by cellulose acetate membrane electrophoresis.
Using M/15 phosphate buffer (pH 7.0, ionic strength 0.147) as electrolyte, electrophoresis was conducted for 20 minutes at a constant current of 0.6mA/cm across membrane. The running zones of pigments moved all to the anode, and separation was complete, with the degree of mobility in the order of amaranth, laccaic acid and carminic acid.View full abstractDownload PDF (1045K) -
Effects of Food Colors on the Leucine Aminopeptidase Activity and Amino Acid Uptake in Rat Small IntestineKeiichi TANAKA, Kunio OKAHARA1973 Volume 14 Issue 3 Pages 234-238
Published: June 05, 1973
Released on J-STAGE: March 01, 2010
JOURNAL FREE ACCESSIn order to study the safety of food additives with regard to their effects on alimentary tract, we examined the effects of food colors on leucine aminopeptidase activity and amino acid uptake in rat small intestine.
Leucine aminopeptidase activity in the homogenate of intestinal mucosa was estimated by use of leucine-β-naphthylamide as the substrate. Amino acid uptake was examined by the tissue accumulation method of α-aminoisobutyric-3-14C-acid in intestinal segment of rat. The results obtained are as follow;
(1) The leucine aminopeptidase activity in mucosal homogenate was extremely decreased by the addition of xanthene or triphenylmethane colors to the incubation mixture (final concentration; 10-4M), although azo and indigoid colors gave no effect.
(2) Decrease in the enzyme activity was not observed by sorbate, saccharin and other several food additives. Xanthene-related compounds, fluorescein and certain halogenated fluorescein derivatives, inhibited leucine aminopeptidase activity.
(3) Lineweaver-Burk's plot showed that inhibition of xanthene colors was “uncompetitive type”.
(4) Tissue accumulation of α-aminoisobutyric acid in intestine was inhibited by xanthene color, phloxine, in the same rate as the metabolic inhibitors, cyanide and 2, 4-dinitrophenol. However, other types of colors did not give the inhibitory effect.
(5) The declines of leucine aminopeptidase activity and amino acid uptake were not observed with the rats administrated food color per os for three months.View full abstractDownload PDF (874K) -
Simultaneous Analysis of Metals by UHF Plasma Spectra AnalyzerKatsuhiko IKEBE, Yukio TANAKA, Ryoichi TANAKA, Nobuharu KUNITA1973 Volume 14 Issue 3 Pages 239-244
Published: June 05, 1973
Released on J-STAGE: March 01, 2010
JOURNAL FREE ACCESSIn order to carry out the simultaneous analysis of metals in foods by UHF Plasma Spectra Analyzer, the optimal conditions were investigated.
The most suitable analytical conditions were as followed: magnetron anode current 270mA, field current 360mA, Plasma gas 1.8L/min, sheath gas 3.0L/min. After ashing of the samples, it was found to be suitable for the preparation of solution to use 0.5 N-nitric acid. Measurement of diverse ions was influenced considerably by sodium and potassium, however, the sensitivity was increased by the dilution of solution.
The detection limit of each metals in unpolished rice was measured under the conditions above-mentioned, and simultaneous analysis of metals in tangle, coffee bean, spinach, fish (crucian carp) and soybean were examined.View full abstractDownload PDF (947K) -
Naoki SATO, Katsuhiko TSURUTA, Isao KAMADA, Seiichi NARITA, Hiroshi AB ...1973 Volume 14 Issue 3 Pages 245-248
Published: June 05, 1973
Released on J-STAGE: March 01, 2010
JOURNAL FREE ACCESSA simple method for determination of tin in a large number of canned foods were investigated by atomic absorption spectrophotometry with a three-slot burner and acetyleneair flame.
Samples were prepared from the foods mainly by extraction with hydrochloric acid and partially by the method of wet ashing.
Among various coexistent substances, an effect of concentration of sugar was investigated, and it was found that increase in concentration of sugar caused considerable decrease in absorbance.
Dissolved tin in syrups of canned foods was able to be determined sufficiently exactly by extraction with hydrochloric acid and standard addition method.
Dissolving of tin in canned foods proceeded after opening of the canned foods, and was essentially correlated with inside coating materials of cans.View full abstractDownload PDF (635K) -
Formation of Formaldehyde in Hydrogen Peroxide Treated FoodsHajimu ISHIWATA, Akio TANIMURA1973 Volume 14 Issue 3 Pages 249-252
Published: June 05, 1973
Released on J-STAGE: March 01, 2010
JOURNAL FREE ACCESSIdentification of the Escherichia coli K-12 (E. coli) inhibiting substance formed by the decomposition of glycine with hydrogen peroxide (H2O2) or bleaching of foods with H2O2 were studied.
The inhibition substance zone appeared at Rf 0.2-0.4 on the bioautogram (n-butanol: acetic acid: water=60: 15: 25) of glycine oxidation products, and the substance was positive to qualitative tests of formaldehyde (Rimini test, egg albumin iron test, acetylacetone test and chromotropic acid test). Melting point, paper chromatogram, thin-layer chromatogram and infrared spectrum of yellow crystal obtained with the addition of acetylacetone reagent to the extracts from the zone of Rf 0.2-0.4 on the paper chromatogram were coincident with those of 3, 5-diacetyl-1, 4-dihydrolutidine (DDL).
Since E. coli inhibiting substance in the glycine oxidation products was proved to be formaldehyde from the above results, it was examined on the formation of formaldehyde in foods treated with H2O2.
Commercial foods containing 2-30ppm of formaldehyde were bleached with 3% hydrogen peroxide under the following conditions (10g of the samples were treated with 50ml of 3% H2O2, and kept at 50°C for 1 hour). Formaldehyde was produced in these samples at the level of 16-34ppm, while its concentration in soaking solutions was within the range of 10-68ppm. Further, the amounts of formaldehyde were determined after standing at room temperature for a week, and 40-68ppm of formaldehyde was found in the foods. In case distilled water was used as soaking solution, no increase in formaldehyde content was observed.View full abstractDownload PDF (768K) -
Katsuhiko NODA, Naoyoshi KENJO, Tsuyoshi TAKAHASHI1973 Volume 14 Issue 3 Pages 253-257
Published: June 05, 1973
Released on J-STAGE: March 01, 2010
JOURNAL FREE ACCESSA rapid method was described for the dialysis, extraction and quantitative determination of sorbic acid in several kinds of cheeses. Sorbic acid in Cheddar cheese, processed cheese and cheese spread was extracted by dialysis, sodium bicarbonate solution was added and shaken with ethyl ether for removing some interfering substances. Sorbic acid was extracted by ethyl ether in low pH range and determined by gas-liquid chromatography using 10% neopentyl glycol succinate +1% H3PO4 as liquid phase of column. It was apparent that by this method benzoic acid, dehydroacetic acid and some other substances did not interfere with the sorbic acid analysis. This method was found to be useful for routine analysis.View full abstractDownload PDF (636K) -
Masahiro IWAIDA, Ryoko EBINE, Akio TANIMURA1973 Volume 14 Issue 3 Pages 258-263
Published: June 05, 1973
Released on J-STAGE: July 27, 2010
JOURNAL FREE ACCESS -
Distribution of Dimethylnitrosamine in Marine FoodsMasayoshi NAKAMURA, Mutsuo USUKI1973 Volume 14 Issue 3 Pages 264-271
Published: June 05, 1973
Released on J-STAGE: March 01, 2010
JOURNAL FREE ACCESSDownload PDF (1038K) -
Kiyoshi TERAO, Mikio YAMAZAKI, Takaaki MIYAKI1973 Volume 14 Issue 3 Pages 272-273
Published: June 05, 1973
Released on J-STAGE: March 01, 2010
JOURNAL FREE ACCESSDownload PDF (1448K)
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