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Volume 54 (2013)
- Issue 6 Pages 385-
- Issue 5 Pages 351-
- Issue 4 Pages 251-
- Issue 3 Pages 173-
- Issue 2 Pages 83-
- Issue 1 Pages 1-
Volume 54, Issue 3
Displaying 1-10 of 10 articles from this issue
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Original Papers
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Kunihiko TAKAHASHI, Rie ISHII, Ryuji MATSUMOTOArticle type: Original Paper
2013 Volume 54 Issue 3 Pages 173-177
Published: June 25, 2013
Released on J-STAGE: July 18, 2013
JOURNAL FREE ACCESS2-Alkylcyclobutanones (2-ACBs) are recognized as a marker of irradiation in lipid-containing food products. Here, a rapid method for the analysis of 2-dodecylcyclobutanone (2-DCB) and 2-tetradecylcyclobutanone (2-TCB) in irradiated food products using direct solvent extraction (DSE) was developed, and the extraction efficiency was compared to that of the Soxhlet extraction method (EN 1785), which is the official method for this analysis. Briefly, 2-ACBs were extracted either by using a Soxhlet apparatus or by DSE with n-hexane. The lipid extract was purified by GPC followed by a silica gel cartridge column. Finally, 2-DCB and 2-TCB were measured using GC-MS/MS. The extraction efficiency of 2-ACBs by the DSE method was similar to that of the Soxhlet extraction method. The trueness of 2-DCB and 2-TCB spiked at 50 ng/g in lipid extracts of beef, pork, chicken, cheese and salmon with the proposed method were 76.6% to 91.6% and 81.3% to 109.0%, respectively. The limits of detection for 2-DCB and 2-TCB in lipid extracts were 15 and 20 ng/g, respectively.View full abstractDownload PDF (299K) -
—Comparison of Detection Rates and Concentrations before and after the Fukushima Daiichi Nuclear Power Plant Accident—Yukinori BANNO, Mikio NAMIKAWA, Mariko MIWA, Soichirou BAN, Taichi ORI ...Article type: Original Paper
2013 Volume 54 Issue 3 Pages 178-187
Published: June 25, 2013
Released on J-STAGE: July 18, 2013
JOURNAL FREE ACCESSSince the Chernobyl Nuclear Power Plant accident, radioactive substances have been continually monitored in foods collected in the city of Kyoto, Japan. The importance of the monitoring was increased by the Fukushima Daiichi Nuclear Power Plant accident in March 2011. Here, the detection rates and concentrations of radioactive substances were compared among food samples collected before and after the accident in Fukushima prefecture. Before the accident, 137Cs was the only radioactive substance detected in foods. The detection rate was 70% for fish and shellfish samples and the highest concentration was 1.7 Bq/kg. It was also 83% for fresh mushroom samples and the highest concentration was 7.5 Bq/kg. In contrast, the detection rate was low for vegetables and the concentrations were also lower than those of the above samples. On the other hand, after the accident, 131I was detected in food produced in the Tohoku and Kanto areas. Actually, 131I (3,400 Bq/kg), 134Cs (280 Bq/kg), and 137Cs (280 Bq/kg) were detected in mizuna, a leaf vegetable, on March 23, 2011. These radioactive substances were detected in all leaf vegetable samples examined in March and April 2011, but they were not detected in samples examined in November 2011. 131I was not detected in any food sample examined after May 2011. However, 137Cs (average=7.9 Bq/kg) was consistently detected in fish and shellfish samples until November, although the concentrations were less than the regulatory limits. It appears unlikely that foods containing radioactive substances over the regulatory limits are currently being distributed in Kyoto.View full abstractDownload PDF (482K) -
Mami GODA, Manabu HORIKAWA, Takashi IWASHITA, Motomitsu SAWADA, Daisuk ...Article type: Original Paper
2013 Volume 54 Issue 3 Pages 188-197
Published: June 25, 2013
Released on J-STAGE: July 18, 2013
JOURNAL FREE ACCESSThree unknown colors (A1, A2 and A3) in Food red No. 102 (R102) were identified by LC-MS and NMR analysis. Red dye A1 was azo rubine (AZO), which is not designated as a coloring agent in Japan. Red dye A2 was a structural isomer of Fast Red E (FRE), which is also not designated as a coloring agent in Japan. Red dye A3 was predicted to be an overreaction product of R102, possessing the R102 structural framework. Furthermore, AZO, which was assumed to have been produced by dimerization of a diazonium salt used as a synthetic intermediate of R102, was also identified in Food red No. 2 (R2).View full abstractDownload PDF (1354K) -
Seiya HARADA, Masato FURUKAWA, Eisuke TOKUOKA, Kazutoshi MATSUMOTO, Sh ...Article type: Original Paper
2013 Volume 54 Issue 3 Pages 198-203
Published: June 25, 2013
Released on J-STAGE: July 18, 2013
JOURNAL FREE ACCESSMore than 27 outbreaks per year of food poisoning caused by consuming horse meat were reported in Kumamoto Prefecture (including Kumamoto City) from January 2009 to September 2011. It was found that the causative agent of the outbreaks was a protein with a molecular weight of 15 kDa that had originated from bradyzoites of Sarcocystis fayeri parasitizing the horse meat. Rabit ileal loop tests showed that pepsin treatment of homogenates of frozen horse meat containing the cysts of S. fayeri induced loss of toxicity, presumably by digestion of the proteinous causative agent(s). Slices of horse meat containing the cysts were frozen at below -20°C for various periods. The cysts were collected after thawing the slices, then treated in an artificial stomach juice containing pepsin. The bradyzoites of the cysts kept at -20°C for 48 hr or more completely disappeared. Simultaneously, the 15 kDa protein also disappeared in the frozen cysts. After notifying the public and recommending freezing treatment of horse meat, no subsequent cases of food poisoning were reported. This indicates that freezing of horse meat is effective to prevent the occurrence of food poisoning caused by consuming raw horse meat containing S. fayeri.View full abstractDownload PDF (2619K) -
Sayuri TSURUDA, Tomonori SAKAMOTO, Kouichi AKAKIArticle type: Original Paper
2013 Volume 54 Issue 3 Pages 204-212
Published: June 25, 2013
Released on J-STAGE: July 18, 2013
JOURNAL FREE ACCESSA rapid and simple method for the simultaneous determination of twelve sweeteners and nine preservatives in various foods by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. The sweeteners and preservatives were extracted from solid samples with 80% and 50% methanol and from liquid samples with 80% methanol, followed by Oasis WAX cartridge cleanup. The LC separation was performed on a XSelect CSH Phenyl-Hexyl column (5 μm, 2.1 mm ×150 mm) with a mobile phase of 10 mmol/L acetate buffer (pH 4.0)–acetonitrile and MS detection with negative ion electrospray ionization. The quantification limits of acesulfame K (AK), alitame (AL), aspartame (ASP), cyclamic acid (CYC), neotame (NEO), saccharin Na (SAC), p-hydroxybenzoic acid methyl (PHBA-Me), p-hydroxybenzoic acid ethyl (PHBA-Et), p-hydroxybenzoic acid isopropyl (PHBA-iPr), p-hydroxybenzoic acid propyl (PHBA-Pr), p-hydroxybenzoic acid isobutyl (PHBA-iBu) and p-hydroxybenzoic acid butyl (PHBA-Bu) were 0.001 g/kg, those of dulcin (DU), glycyrrhizic acid (GLY), neohesperidin dihydrochalcone (NHDC), rebaudioside A (REB), stevioside (STV), sucralose (SUC) and benzoic acid (BA) were 0.005 g/kg, and those of sorbic acid (SOA) and dehydroacetic acid (DHA) were 0.02 g/kg. The mean recoveries from ten kinds of foods fortified at the levels of 0.02 and 0.2 g/kg were 70.9–119.0%, and their relative standard deviations were 0.1–11.7%.View full abstractDownload PDF (623K) -
Motoki OGISO, Shihomi ITO, Ayako KIMURA, Maki SAITO, Ayako SASAKI, Nob ...Article type: Original Paper
2013 Volume 54 Issue 3 Pages 213-218
Published: June 25, 2013
Released on J-STAGE: July 18, 2013
JOURNAL FREE ACCESSCorn is a major ingredient of mixed feed, and it has been reported that corn may be contaminated with deoxynivalenol (DON). There is also a possibility of contamination with other trichothecenes. Recently, corn-derived products such as Distiller's Dried Grains with Solubles (DDGS), corn gluten feed and corn gluten meal have been introduced and used for mixed feed. However the actual occurrence of trichothecenes has not been sufficiently investigated. So, in this study, we analyzed DON and 6 other trichothecenes, i.e., 3-acetyl-deoxynivalenol (3AcDON), 15-acetyl-deoxynivalenol (15AcDON), T-2 toxin, HT-2 toxin, nivalenol, and fusarenon-X, in DDGS, corn gluten feed, corn gluten meal, and mixed feed containing corn-derived ingredients. The major trichothecenes identified in the samples tested were DON, 3AcDON and 15AcDON. In particular, DON, 3AcDON and 15AcDON were detected in most DDGS and corn gluten feed samples. Most samples of mixed feed contained DON and 15AcDON, but only one mixed feed sample contained 3AcDON. In contrast, corn gluten meal was contaminated with lower levels of these compounds than the other samples tested. Among 36 corn gluten meal samples, DON was detected in 24 and 15AcDON was detected in 20 samples. 3AcDON was not detected in any of the corn gluten meal samples.View full abstractDownload PDF (168K)
Note
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Norinaga MIWA, Hirotaka KONUMA, Susumu KUMAGAIArticle type: Note
2013 Volume 54 Issue 3 Pages 219-223
Published: June 25, 2013
Released on J-STAGE: July 18, 2013
JOURNAL FREE ACCESSThe survival and recovery of Salmonella Enteritidis inoculated on stainless steel surfaces with different metal contents and surface finishes were examined. Two S. Enteritidis strains possessing different levels of biofilm productivity were inoculated with tryptone soya broth (TSB) and egg yolk emulsion (EY) on the surface of stainless steel squares (1 cm×1 cm) and stored at 22℃ under a dry condition. After storage, cells were recovered from the stainless steel surfaces by swabbing with a cotton swab. The numbers of cells recovered by swabbing and the cells remaining on the stainless steel squares were counted. The survival ratio of the strain possessing high biofilm productivity was greater than that of the strain possessing low biofilm productivity. The survival ratio of S. Enteritidis suspended in TSB was often higher than that in EY. There were no significant differences in the survival and recovery ratios of S. Enteritidis based on stainless steel composition or surface finish. From all except one sample, more than 98% of viable cells of S. Enteritidis were recovered by swabbing with a cotton swab.View full abstractDownload PDF (323K)
Reports
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Maki KOBAYASH, Kenji OHTSUKA, Yasuhiro TAMURA, Sanae TOMIZAWA, Teruaki ...Article type: Report
2013 Volume 54 Issue 3 Pages 224-231
Published: June 25, 2013
Released on J-STAGE: July 18, 2013
JOURNAL FREE ACCESSA survey of pesticide residues in 116 imported tea samples on the Tokyo market from April 1992 to March 2010 was carried out. Twenty-two kinds of pesticides, including organophosphorus, organochlorine, pyrethroid and others, were detected at levels between trace (below 0.01 ppm) and 4.0 ppm in 76 samples. The rate of detection was 90% in non-fermented tea, 89% in semi-fermented tea, and 49% in fermented tea. Organophosphorus pesticide was not detected in puer tea, which is fermented with bacteria. The pesticide residues tended to be decreased by a fermentation process. However, organochlorine and pyrethroid pesticides appeared to be chemically stable, so they were still detected in fermented teas. Residue levels of these pesticides were calculated as less than 1% of ADI, except for ethion (45% of ADI) based on the daily intake of tea. Therefore, these teas should be safe when drunk in customary amounts.View full abstractDownload PDF (487K) -
Takaomi TAGAMI, Akihiro TAKEDA, Akiko ASADA, Airin AOYAMA, Takahiro DO ...Article type: Reports
2013 Volume 54 Issue 3 Pages 232-236
Published: June 25, 2013
Released on J-STAGE: July 18, 2013
JOURNAL FREE ACCESSWe developed a method for the separation and identification of illegal adulterants (hydroxythiohomosildenafil, aminotadalafil, thiosildenafil, dimethylsildenafil, and thiodimethylsildenafil) from dietary supplements using high-performance liquid chromatography-mass spectrometry. The separation was achieved on a C18 column: the mobile phase consisted of 5 mM ammonium formate (pH 6.3)–acetonitrile (75 : 25, v/v) and acetonitrile, with gradient elution at a flow rate of 0.2 mL/min. The proposed method could also be used to separate vardenafil, homosildenafil, and dimethylsildenafil, all of which have the same molecular weight. Furthermore, the proposed method could simultaneously separate hydroxythiohomosildenafil, aminotadalafil, thiosildenafil, dimethylsildenafil, thiodimethylsildenafil, vardenafil, and homosildenafil. Thus, this method may be useful to identify medicinal ingredients for erectile dysfunction and their analogs and to control the quality of dietary supplements.View full abstractDownload PDF (425K)
Validation Study
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Satoshi TAKATORI, Haruna YAMAMOTO, Naoki FUKUI, Satoko YAMAGUCHI, Yoko ...Article type: Validation Study
2013 Volume 54 Issue 3 Pages 237-249
Published: June 25, 2013
Released on J-STAGE: July 18, 2013
JOURNAL FREE ACCESSA validation study was conducted on a rapid multiresidue method for determination of pesticide residues in vegetables and fruits by LC-MS/MS. Pesticide residues in the vegetables or fruits were extracted with acetonitrile in a disposable tube using a homogenizer, followed by salting out with anhydrous magnesium sulfate and sodium chloride in the presence of citrate salts for buffering. The extract was purified with a double-layered cartridge column (graphite carbon black/primary secondary amine silica gel; GCB/PSA). For citrus fruits a purification step with a C18 column was added (this column was connected to the GCB/PSA column). After removal of the solvent, the extract was resolved in methanol/water and analyzed by means of LC-MS/MS. The method was validated according to the method validation guideline of the Ministry of Health, Labour and Welfare of Japan; recovery tests were performed on 8 kinds of vegetables and fruits [cabbage, cucumber, Japanese radish, onion, potato, spinach, Amanatsumikan (a citrus fruit) and apple] by fortification of 161 pesticide residues at the concentrations 0.01 and 0.05 μg/g (each concentration of pesticide residue was extracted from 2 samples on 5 separate days). The trueness of the method for 127 pesticides in all 8 commodities was 70–120% with satisfactory repeatability and within-run reproducibility. This method is concluded to be applicable for determination of pesticide residues in vegetables and fruits.View full abstractDownload PDF (464K)
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