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Volume 55 (2014)
- Issue 6 Pages 231-
- Issue 5 Pages 193-
- Issue 4 Pages 167-
- Issue 3 Pages 135-
- Issue 2 Pages 65-
- Issue 1 Pages 1-
Volume 55, Issue 3
Displaying 1-5 of 5 articles from this issue
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Original Papers
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Takashi CHIBA, Yumi TAKAHASHI, Kenji SADAMASU, Akiko NAKAMA, Akemi KAIArticle type: Original Paper
2014 Volume 55 Issue 3 Pages 135-141
Published: June 25, 2014
Released on J-STAGE: July 02, 2014
JOURNAL FREE ACCESSWe describe a simple method for discrimination of Aspergillus flavus group fungi, including aflatoxin (AF) producers, by means of molecular-biological analysis of 45 strains of A. flavus. First, 20 strains of A. flavus were compared using phylogenetic tree analysis based on the nucleotide sequences of ITS 1-5.8S-ITS 2 (ITS-1/2) and aflR-aflJ intergenic spacer (aflR/J-IGS). In this analysis, the tested strains were discriminated into 4 groups at the aflR/J-IGS region. Although ITS-1/2 region analysis could not discriminate between A. flavus (AF producers) and A. oryzae/A. flavus (AF nonproducers), aflR/J-IGS region analysis could discriminate between these groups. Moreover, 45 strains of A. flavus were compared by means of both phylogenetic tree analysis based on the aflR/J-IGS region and the conventional aflatoxin production test (culture method). The phylogenetic tree analysis of the tested strains was consistent with the findings of the culture method. In addition, 49 strains of A. flavus and related species (Aspergillus spp.) were tested by multiplex PCR with primers designed on the basis of the phylogenetic tree analysis. These results were consistent with phylogenetic tree analysis based on the aflR/J-IGS region for 41 strains.View full abstractDownload PDF (711K) -
Shizuka SAITO-SHIDA, Satoru NEMOTO, Rieko MATSUDAArticle type: Original Paper
2014 Volume 55 Issue 3 Pages 142-151
Published: June 25, 2014
Released on J-STAGE: July 02, 2014
JOURNAL FREE ACCESS
Supplementary materialA multiresidue method for analyzing pesticides in vegetables and fruits by supercritical fluid extraction (SFE) and LC-MS/MS was developed. The sample preparation and SFE parameters were optimized for extracting LC-amenable polar and medium-polarity pesticides. High recoveries were achieved for most of the tested pesticides by extracting a 1 : 1 : 1 sample–Celite–anhydrous magnesium sulfate mixture with supercritical carbon dioxide at 16.4 MPa at 40℃ for 30 min with methanol added as a modifier. The recoveries of 117 pesticides fortified with 0.01 mg/kg of each pesticide were 70–120%, and the relative standard deviations were less than 25% for 112 pesticides in tomato and 103 pesticides in cucumber. No significant differences were observed in the residue concentrations determined in real samples by the SFE method and the liquid extraction method (the modified Japanese official method). Higher recoveries of polar pesticides, such as acephate and methamidophos, were achieved by the developed SFE method than by the liquid extraction method.View full abstractDownload PDF (367K) -
Ryohei TATSUNO, Taiki SORIMACHI, Shigeto TANIYAMA, Naomasa OSHIRO, Hir ...Article type: Original Paper
2014 Volume 55 Issue 3 Pages 152-156
Published: June 25, 2014
Released on J-STAGE: July 02, 2014
JOURNAL FREE ACCESSA feeding experiment of TTX-containing diet was conducted using the small scavenging marine snails Pliarcularia globosa and Reticunassa festiva. Seventy-five specimens of each species were divided into 15 groups of 5 individuals, of which 3 groups were directly submitted, without feeding, to toxin quantification as described below. TTX was not detected. Each of the remaining 12 groups was accommodated in a plastic case (80×70×40 mm) filled with seawater, and fed for 24 hours with ovary tissue (0.1 g) of the pufferfish Takifugu vermicularis, whose TTX content had previously been determined. Then the seawater was exchanged for fresh seawater, the snails were reared for 4 days without feeding, and then the seawater was changed again. This feeding/rearing cycle (5 days) was repeated 8 times, and 3 groups were sampled every 2 cycles. The combined viscera and combined muscle of each group were each extracted with 0.1% aqueous acetic acid, and then TTX was quantified by liquid chromatography-mass spectrometry. The estimated amount of ingested TTX was calculated by multiplying the difference between the amounts of ovary tissue supplied and remaining by the toxin content (122–126 MU/g). Similar mean values of 5.1 MU/group/cycle in P. globosa and 5.3 MU/group/cycle in R. festiva were obtained. Toxin content (TTX amount per gram of tissue) and toxin amount (TTX amount per group) during the experimental period were 0.23–2.85 MU/g and 0.05–0.96 MU/group, respectively, in P. globosa viscera. Both values increased markedly from the 2nd cycle to the 6th cycle. In contrast, no such increase in toxin content/amount was observed throughout the experimental period in P. globosa muscle (<0.05–0.86 MU/g, <0.02–0.27 MU/group), R. festiva viscera (<0.05–0.8 MU/g, <0.02–0.33 MU/group), and R. festiva muscle (<0.05–0.81 MU/g, <0.02–0.23 MU/group). The remaining ratio of TTX (percentage of total toxin amount [sum of the toxin amount of viscera and muscle] to estimated TTX ingestion amount) was less than 4% in P. globosa, and less than 2% in R. festiva after the 4th cycle, suggesting that the possibility that these two species would accumulate TTX at levels high enough to raise food hygiene issues is low.View full abstractDownload PDF (483K)
Reports
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Yoshio OGAWA, Dai HIROSE, Ayano AKIYAMA, Masakatsu ICHINOEArticle type: Report
2014 Volume 55 Issue 3 Pages 157-161
Published: June 25, 2014
Released on J-STAGE: July 02, 2014
JOURNAL FREE ACCESSPenicillium roqueforti is a well known starter used for blue cheese production. Two closely related species, P. carneum and P. paneum, were previously classified as varieties of P. roqueforti. Penicillium roqueforti does not produce patulin, a mycotoxin harmful for human health, whereas both P. carneum and P. paneum actively produce this toxin. From the viewpoint of food safety, it is thus important to confirm that P. carneum and P. paneum are not used for cheese production. In the present study, the taxonomic position of Penicillium strains used for blue cheese production was examined on the basis of the partial sequence of β-tubulin. Twenty-eight Penicillium strains isolated from blue cheeses were investigated. All the examined strains belonged to P. roqueforti. Therefore, the Penicillium strains used for production of the blue cheese samples examined here do not negatively impact on human health.View full abstractDownload PDF (215K) -
Yukari KATO, Hisaya TERADAArticle type: Report
2014 Volume 55 Issue 3 Pages 162-166
Published: June 25, 2014
Released on J-STAGE: July 02, 2014
JOURNAL FREE ACCESSA rapid and simple method using ultra high performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) was developed for the determination of linamarin in cassava products and beans containing cyanogen compounds. Linamarin was extracted with acetonitrile–water (3 : 1) cleaned up using an amino solid-phase extraction cartridge, and then determined by UHPLC-MS/MS. The recoveries from cassava fortified at the levels of 10 μg/g and 100 μg/g were 96.1% and 95.3%, respectively, and their relative standard deviations were 2.6% and 1.4%, respectively. The recoveries from tapioca fortified at the levels of 1 μg/g, 10 μg/g and 100 μg/g were 81.1%, 91.9% and 97.1%, respectively, and their relative standard deviations were 3.3%, 5.4% and 2.1%, respectively. The contents of linamarin in 14 cassava, 9 tapioca and 4 butter bean samples were surveyed by this method, and linamarin was detected in the range of 0.1–245 μg/g in 11 cassava, 0.1–0.5 μg/g in 5 tapioca and 4,950–5,590 μg/g in 4 butter bean samples. The quantitation limit was 0.1 μg/g and the detection limit was 0.03 μg/g.View full abstractDownload PDF (350K)
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