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Volume 19, Issue 6
Displaying 1-8 of 8 articles from this issue
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TOSHIHARU KAWABATA, HIDENORI SHYAZUKI1972 Volume 19 Issue 6 Pages 241-248
Published: June 15, 1972
Released on J-STAGE: January 20, 2010
JOURNAL FREE ACCESSDEVIK (1967) has reported the formation of N-nitrosamines from the heat induced reactions between D-glucose and several L-amino acids. Studies were undertaken on the possible formation of N-nitrosamines in aqueous model systems consisting of D-glucose or pentoses, and various amino acids or carbonyl compounds. In addition, analyses for N-nitrosamines in such brown colored foods as soy-sauce, Miso, chocolate, coffee, etc. were conducted. Dichloromethane extracts of the heated reaction mixtures or of foods were analysed by thin-layer chromatography with 2 solvent systems, a gas-liquid chromatograph equipped with an alkali thermoionic detecter, and a tandem gas-liquid chromatograph- mass spectrometer.
No evidence for the presence of N-nitrosamines was confirmed, while the presence of pyrazines were found in the extracts. It is concluded that DEVIK probably misidentified nonenzymatic browning products such as pyrazines or other substance as N-nitrosamines.View full abstractDownload PDF (384K) -
TAKENORI MOURI, WATARU HASHIDA, IWAO SHIGA1972 Volume 19 Issue 6 Pages 249-254
Published: June 15, 1972
Released on J-STAGE: March 08, 2010
JOURNAL FREE ACCESSEnzyme fractions decomposing nucleic acid and related substances were isolated from the fruiting body of Matsu-take (Tricholoma matsutake), and they were partially purified by chromato- graphy using DEAE-Cellulose column.
Ribonuclease (RNase) from Matsu-take had an optimum temperature of 60°C and a pH range of 7.0-7.5. The ranges of optimum temperature and pH of phosphodiesterase and phosphomono- esterase were 40-45°C and pH 6.0-6.5 and 40-45°C and pH 4.5-4.8, respectively.
Yeast RNA was degraded by RNase fraction of Matsu-take under optimum condition for its activity, and four kinds of 5'-nucleotides, namely 5'-CMP, 5'-UMP, 5'-AMP and 5'-GMP were accumulated abundantly in its digest. The acid range-enzyme activities of fruiting bodies are different from those of Shii-take, and common mushrooms.View full abstractDownload PDF (253K) -
Part IX. On the utilization of natural tocopherol mixture on the instant ramenYASUJI OKADA1972 Volume 19 Issue 6 Pages 255-261
Published: June 15, 1972
Released on J-STAGE: January 20, 2010
JOURNAL FREE ACCESSThe oxidative stability of lard and instant ramen added with natural tocopherol mixture (M-Toc.) was compared with those of lard and instant ramen to which butylated hydroxy anisol (BHA) and sesame oil were added.
1) M-Toc.showed a good antioxidative effect when the concentration was about 0.03% level to lard. Citric acid (0.005%) promoted the effect remarkably as a synergist. However, such effect of multiplication on the antioxidative activity of M-Toc. was not recognized by the addition of BHA.
2) When employed with sesame oil, M-Toc. showed a better effect as an antioxidant on the lard contained a little sesame oil.
3) The thermostability of lard added with M-Toc. was stronger than that of lard added with BHA.
In frying test, the oxidative stability of lard added with M-Toc. was also better than that oflard added with BHA.
The fat rancidity of instant ramens added with M-Toc. or BHA was similar when they were stored either at 60°C in a dark room or at room temperature in scattered light.View full abstractDownload PDF (350K) -
Part II. Changes of trypsin inhibitor activity during heat treatment and curd formation from soybean milkHIROATSU MATSUOKA, KENJI SASAGO1972 Volume 19 Issue 6 Pages 262-267
Published: June 15, 1972
Released on J-STAGE: January 20, 2010
JOURNAL FREE ACCESSChanges of trpysin inhibitor (TI) activity existing in soybean milk, whey and curd were investigated to improve the ripening condition of cheese-like product.
1) The degree of residual TI activity in soybean milk samples after heat treatment are as follows: 100°C for 10min., 32.8-33.9%; 100°Cfor 20min., 27.4-31.3%; 120°C for 10min., 10.8-15.1% and 120°C for 20min., 3.5-8.1%.
2) Trypsin inhibitor activity units per mg of solid matter were 0.31 and 0.05 in whey samples treated at 100°C for 10min. and 120°C for 20min., respectively. In curd samples, they showed 0.19 and 0.09, respectively. Total TI activity existing in curd samples showed higher than that in whey samples.
4) Protease activities, produced by Pen. caseicolum, under the condition at pH 6.7 and 7.6 were little inhibited by the addition of unheated soybean milk sample and curd made from heat treated soybean milk (120°C for 20min.).View full abstractDownload PDF (316K) -
Part III. Test on aflatoxin contamination and its possibility on riceMASARU MANABE, SHINJI MATSUURA1972 Volume 19 Issue 6 Pages 268-274
Published: June 15, 1972
Released on J-STAGE: January 20, 2010
JOURNAL FREE ACCESSExtensive studies were made to investigate whether or not rice, one of the important raw materials of fermented foods, contained aflatoxin and had possibility of aflatoxin contamination. Forty six samples of domestic rice (stored for 0.5 to 1.5 years) throughout Japan and 11 samples imported from various countries in 1966 or 1967 were subjected to the investigation. Beforeaflatoxin analysis, three kind samples of the rice were prepared by treatment in the following ways: (I) Non treatment rice; (II) cultured rice: it was prepared by adding sterilized water to rice and cultivating micro-organisms on the surface of its grains at 30°C for 1 to 2 weeks; (III) another cultured rice: it was also prepared on the same way after sterilizing the surface of the grains.
Although aflatoxin-like substances were detected in a few samples but no aflatoxin was detected in all the samples. Molds isolated from rice were investigated on the possibility to produce aflatoxin by cultivating on rice. As the result, no mold produced aflatoxin.View full abstractDownload PDF (387K) -
Part IV. Degradation of added aflatoxin during miso fermentationMASARU MANABE, SHINJI MATSUURA1972 Volume 19 Issue 6 Pages 275-279
Published: June 15, 1972
Released on J-STAGE: January 20, 2010
JOURNAL FREE ACCESSAs a basic experiment for the study of aflatoxin degradation during fermentation of miso, the effect of hydrogen-ion concentration to the degradation of aflatoxin was examined. It was found that the pH value for the most effectiVe degradation of aflatoxin was over 9 and contrary the most stable pH values for aflatoxin were 4-5. The pH values of 95 samples of the commercial miso from all of the prefectures in Japan were mostly between 4.6-5.4. As the result of this survey, it was shown that there was no effect of pH value of the miso as regard to aflatoxin degradation.
A certain amount of aflatoxin was added to green miso before fermentation in order to investigate the degradation of the toxin during miso fermentation. There was some degradation of aflatoxin B1 and G1 in miso in the early stage of the fermentation, but in the later the velocity was remarkably reduced. As the result, above 50 percent of aflatoxin B1 and G1 remained in miso after 1 month fermentation. With regard to aflatoxin B2 and G2, no degradation was detected during miso fermentation.View full abstractDownload PDF (277K) -
YOSHIMASA YAMANO, MICHIKO TAKAGAWA, YOSHIAKI FUKUI1972 Volume 19 Issue 6 Pages 280-282
Published: June 15, 1972
Released on J-STAGE: January 20, 2010
JOURNAL FREE ACCESSEating qualities of cooked rice stored in an electric jar were investigated.
Hardness with a texturometer increased during storage, and adhesiveness did not change so remarkably. The difference between the texture of control and that of the sample stored for 20.5 hours was not significant. Change in color was observed, but very little after storage about a day. Flavor of the sample stored 14 hours was significantly distinguished from that of control. This concepted odor was not so bad as unacceptable.
From these results, physical qualities of cooked rice stored in an electric jar a day is considered to be acceptable.View full abstractDownload PDF (146K) -
1972 Volume 19 Issue 6 Pages 283-292
Published: June 15, 1972
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESSDownload PDF (754K)
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