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Volume 37 (1996)
- Issue 6 Pages 343-
- Issue 5 Pages 247-
- Issue 4 Pages 165-
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- Issue 2 Pages 65-
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Volume 37, Issue 6
Displaying 1-11 of 11 articles from this issue
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Mitsuo NAKAZATO, Hitoshi OGAWA, Hirofumi USHIYAMA, Chigusa KOBAYASHI, ...1996 Volume 37 Issue 6 Pages 343-350_1
Published: December 05, 1996
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSAn HPLC method was developed for the determination of geniposidic acid (GA) and caffeine (CF) in leaves of Eucommia ulmoides used in health foods. GA and CF in dried leaves were simultaneously extracted with water under reflux by heating. The extract was cleaned up with a C18 and ion-exchange type cartridge, then GA and CF were separated on an ODS column, with a UV detector (GA, 240nm; CF, 275nm). The recoveries of GA and CF added to samples were 94.2-94.7% and 90.4-96.7%, respectively. The determination limits of GA and CF in dried leaves were 10μg/g, and those in beverage samples were 1μg/g.
The GA and CF contents of 15 commercial samples were surveyed. The contents of GA in dried leaves of only Eucommia ulmoides, in mixtures of dried leaves of Eucommia ulmoides and others, and in beverage samples, were 290-1, 500, 160-1, 300 and 3.6-19μg/g, respectively, while CF was only detected in the mixtures with leaves of green tea or oolong tea, at 2, 100-9, 800μg/g.View full abstractDownload PDF (1019K) -
Yumi AKIYAMA, Miho YANG, Takao MITSUHASHI, Nobuyuki TAKEDA, Masahiko T ...1996 Volume 37 Issue 6 Pages 351-362_1
Published: December 05, 1996
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSA method was developed for determining 107 pesticides in agricultural products. Residues were extracted from samples with acetonitrile, and coextractives were removed with both ODS and PSA mini-column cleanup. Analysis was performed by gas chromatography with mass spectrometry. Positive analytes were confirmed on the basis of retention time and relative response ratio of two fragment ions. A limit of detection of 0.01ppm was available for all compounds with two injections per sample for both scan and selected ion monitoring mode analyses.
Recovery data were obtained by fortifying 3 matrices (brown rice, lemon, and spinach) at 0.1ppm. Recoveries were more than 50% except for 6 pesticides, whose recoveries varied among the different matrices. The method demonstrated acceptable performance for screening analysis (including polar compounds). The method was applied to 157 samples. From 69 samples, 34 pesticides were detected at levels of more than 0.01ppm. No sample was contaminated to a level that would contravene the Food Sanitation Law in Japan.View full abstractDownload PDF (1268K) -
Yasuhide TONOGAI, Yukari TSUMURA, Yumiko NAKAMURA, Tadashi SHIBATA1996 Volume 37 Issue 6 Pages 363-371_1
Published: December 05, 1996
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSA rapid analysis of 5 kinds of triazine herbicides and 3 kinds of metabolites in agricultural products by FTD-GC was developed. The pesticides in vegetables and fruits were extracted with methanol, re-extracted with 20% ethyl acetate/n-hexane and then cleaned up on Sep-pak Silica. The pesticides in cereals and beans were extracted with acetonitrile and then cleaned up on Sep-pak Silica, after the removal of lipids with n-hexane.
Recoveries of the pesticides ranged between 50.3 and 92.9% for vegetables and fruits, and between 62.6 and 78.6% for cereals and beans, except for metabolites of metribuzin and cyanazine.View full abstractDownload PDF (940K) -
Analysis of Natural Coloring Matters in Food. VSadaji YAMADA, Harumi OSHIMA, Isao SAITO, Junko HAYAKAWA1996 Volume 37 Issue 6 Pages 372-377_1
Published: December 05, 1996
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSAnalysis of gardenia yellow in food products has been carried out by the detection of crocin and/or geniposide as indicator compounds. However, neither indicator compound was present in a few food products. As a new analytical strategy for gardenia yellow, we adopted crocetin, which is produced from colored components of gardenia yellow by alkaline hydrolysis, as an indicator compound. Crude extracts from food products were hydrolyzed in 0.1N NaOH for 30min at 50°C and the resultant hydrolyzates were analyzed by HPLC. Recoveries from jelly, candy and rice crackers through the whole analytical procedure were 85.6, 86.0 and 80.5%, respectively. When 20 food products labeled as containing gardenia yellow were analyzed, 11 of them had different chromatographic patterns from an authentic preparation and crocin was not detected at all in 5 samples. However, crocetin was found in every food product after alkaline hydrolysis, in the range of 0.1-13.4μg/g (as crocetin). Geniposide was found in only 3 food products.View full abstractDownload PDF (774K) -
Hajimu ISHIWATA, Motohiro NISHIJIMA, Yoshinobu FUKASAWA, Yoshio ITO, T ...1996 Volume 37 Issue 6 Pages 378-384_1
Published: December 05, 1996
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSThe concentration of sorbic acid in foods sold in Japan was estimated using the results of official inspection in F. Y. 1994 by 92 local governments covering almost the whole of Japan. The total number of inspection samples was 38, 133 including 1, 824 of imported foods. The detection rate of sorbic acid in the foods in which the compound is permitted was 53.9% (17, 279/32, 072) at the detection limit of 0.01g/kg. The average concentration of sorbic acid in all samples in which usage is permitted was 16.2% of the legal maximum, but that in the samples in which sorbic acid was actually detected was 40.0% of the limit. The highest concentration of sorbic acid was observed in fish paste products (0.662g/kg). The concentration was 33.1% of the limit. The concentration in vinegar-pickled foods reached 39.0% of the limit. Sorbic acid was found in 318 out of 6, 061 samples in which its use is not permitted (5.2%) such as pickled foods (detection rate was 37.9% of 66 samples examined, and the average concentration in the 66 samples was 0.161g/kg), dry fruits other than prunes (20.9% of 67 samples, and 0.050g/kg), processed seaweed (13.3% of 15 samples, and 0.101 g/kg), etc. No sorbic acid was detected in other foods, such as sauces and other seasonings (198 samples), canned or bottled foods (173 samples), noodles (59 samples), etc.
Estimated daily intake of sorbic acid was calculated to be 29.0mg per capita based on the above results and the consumption amount of foods according to the “National Nutrition Survey” published by the Ministry of Health and Welfare, Japan. This estimated value was almost the same as recent reports of the daily intake of sorbic acid estimated by a marketbasket method in Japan (27.0mg) and by a food additives questionnaire survey of food and food additive producers in the UK (29.4mg). Foods that contributed substantially to the intake of sorbic acid were fish paste (28.3% of total intake), meat products (15.4%) and soybean paste (11.9%).View full abstractDownload PDF (1026K) -
Naoko OZEKI, Hisao OKA, Yoshitomo IKAI, Yuko ITO, Junko HAYAKAWA, Take ...1996 Volume 37 Issue 6 Pages 385-389_1
Published: December 05, 1996
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSA technique for the analysis of coal tar dyes using TLC is described. The 12 coal tar dyes permitted for use in food in Japan were separated on an amino-modified silica gel plate using ethanol-acetonitrile-15% aqueous ammonia-10% aqueous sodium chloride solution (3:3:1:1) as the solvent system. To investigate the applicability of the present amino TLC for the analysis of coal tar dyes in food, 70 foods were analyzed and the chromatographic behavior of the dyes was investigated. The separation was not affected by coexisting substances from the food and the spots showed no tailing and always gave the same Rf values as the standards with good reproducibility. These results indicated that the present amino TLC makes it easier to identify the dyes in food, and this should therefore be a useful technique for the analysis of coal tar dyes in food.View full abstractDownload PDF (611K) -
Hirofumi KUSUNOKI, Teizo TSUKAMOTO, Connie F. C. GIBAS, Ida F. DALMACI ...1996 Volume 37 Issue 6 Pages 390-394_1
Published: December 05, 1996
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSDirect detection of E. coli O157 by flow cytometry (FCM) was performed using heattreated E. coli O157 and FITC-labeled anti-E. coli O157 IgG. The flow cytogram which was obtained within 30 minutes revealed an obvious difference between E. coli O157 treated with and that untreated with FITC-labeled anti-E. coli O157 IgG. There was also a clear difference between E. coli O157 and other strains of E. coli than E. coli O157 in reaction with FITC-labeled IgG.
Among twelve other strains of E. coli tested, six strains exhibited agglutination titers ranging from 1 to 4. The same six strains also gave weakly positive results in FCM. It is therefore possible to count the numbers of E. coli bearing the O157 antigen by using FCM.View full abstractDownload PDF (603K) -
Hideo NAMIKI, Kazuhiko NIINUMA, Mariko TAKEMURA, Reiko TOU, Masaru YAN ...1996 Volume 37 Issue 6 Pages 395-400_1
Published: December 05, 1996
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSThe importance and usefulness of dried food in cases of natural disaster or famine have been widely recognized. Several food drying procedures, such as lyophilization, drying in the sun, sublimation under normal atmospheric pressure, and drying by hot air have been developed. However, little work has been done on biochemical and nutritional evaluation of dried foods produced by different drying procedures. In this report, we compared a newly developed drying procedure using far-infrared irradiation (infrared at 10μm) and lyophilization, which is currently used most frequently. Dehydration of fresh carrots by the two procedures gave essentially the same results. This indicates that the far-infrared irradiation drying is as effective as lyophilization. The amounts of carotenoid and carotene components did not change after lyophilization or far infrared drying at 20°C or 40°C. The amount of carotenoid after far infrared treatment at 60°C decreased to 60% of that in the fresh sample. Microscopic observation of the tissues dried by the two procedures revealed that lyophilzation caused cracks in the tissue. Tissues dried by far-infrared showed a similar structure to the fresh sample and rehydrated tissue retained a natural texture. Additional treatment at 60°C for 1h effectively reduced bacterial numbers in the tissue without loss of carotenoid contents. These results indicate that the far-infrared drying procedure should be useful for the preparation of dried foods.View full abstractDownload PDF (3214K) -
Akiko TERASHI, Shinichi YAMAGUCHI, Shohei YAMAMOTO, Shuichi ETO1996 Volume 37 Issue 6 Pages 401-406_1
Published: December 05, 1996
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSA method for determination of maleic hydrazide in agricultural products by gas chromatography was developed. Maleic hydrazide was extracted by reflux in hydrochloric acid solution. The extract was reacted with dimethyl sulfate under an alkaline condition to form the dimethyl derivative, which was extracted twice with ethyl acetate. After deactivated Florisil column chromatography, the derivative was determined by gas chromatography using a nitrogen-phosphorus detector and gas chromatography-mass spectrometry.
The recovery of maleic hydrazide added to agricultural products at 1ppm was 72.0-98.2%. The detection limit of maleic hydrazide was 0.5ppm.View full abstractDownload PDF (549K) -
Evaluation of Enzyme-Linked Immunosorbent Assay (ELISA) Kit for Paralytic Shellfish Poisoning ToxinsFumiko KASUGA, Yukiko HARA-KUDO, Kenji MACHII1996 Volume 37 Issue 6 Pages 407-410_1
Published: December 05, 1996
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSThe reliability and utility of an enzyme-linked immunosorbent assay (ELISA) kit for paralytic shellfish poisoning (PSP) toxins were examined. Compared with the mouse bioassay, which is an official method worldwide, as described by the Association of Official Analytical Chemists (AOAC), the system showed remarkable sensitivity to saxitoxin (STX). The recovery of saxitoxin diacetate (STX-A) from clam meat was almost 100% over a certain range of the toxin concentration. However, the kit exhibited unpredictable cross-reactivities to a mixture of gonyautoxins (GTXs), and underestimated the toxicity of some naturally contaminated shellfish samples which were harvested in the sea near Japan.
We consider that the existing mouse bioassay can not be replaced with the ELISA kit for the purpose of screening inshore shellfish samples. Considering the advantages of this method, however, the kit should be available for certain uses provided that its limitations are borne in mind.View full abstractDownload PDF (546K) -
Toshihiro NAGAYAMA, Maki KOBAYASHI, Masako ITO, Hiroko SHIODA, Toshio ...1996 Volume 37 Issue 6 Pages 411-417_1
Published: December 05, 1996
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESS
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