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Volume 48 (2007)
- Issue 6 Pages 163-
- Issue 5 Pages 125-
- Issue 4 Pages 83-
- Issue 3 Pages 41-
- Issue 2 Pages 27-
- Issue 1 Pages 1-
Volume 48, Issue 4
Displaying 1-6 of 6 articles from this issue
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Originals
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Izumi YOSHIDA, Satoshi ISAGAWA, Nobuyuki KIBUNE, Megumi HAMANO-NAGAOKA ...2007 Volume 48 Issue 4 Pages 83-89
Published: August 25, 2007
Released on J-STAGE: April 28, 2008
JOURNAL FREE ACCESSFuran is a 5-membered ring compound with high volatility. The U.S. Food and Drug Administration (FDA) has recently published a report on the occurrence of furan in a large number of thermally processed foods. However, the FDA's analytical method, using standard curve addition, is not suitable for high-throughput routine laboratory operations. We developed a rapid and improved method for determination of furan in foods by headspace GC/MS. Quantification was achieved by using an internal standard of d4-furan and an external calibration curve of furan normalized against the internal standard. The incubation temperature for equilibration was set at 60°C to avoid the formation of furan during analysis. The levels of furan in baby foods and infant formulas were determined with this method. Validation data showed good precision and accuracy. The LOD and LOQ were 0.2-0.5 ng/g and 0.5-2 ng/g for various food matrixes, respectively. The level of furan detected was in the range of 1.4 to 90 ng/g in baby foods and in the range of non-detectable to 36 ng/g in infant formulas.View full abstractDownload PDF (226K) -
Tomoko KENJO, Yuka ISHIDE, Koji AOYAMA, Masakatsu ICHINOE2007 Volume 48 Issue 4 Pages 90-96
Published: August 25, 2007
Released on J-STAGE: April 28, 2008
JOURNAL FREE ACCESSThe fungal population and distribution of aflatoxin-producing fungi in 30 samples of imported almond powder products purchased from retail markets were examined in this study. Total counts of fungi ranged from under 1.0×10 colony-forming units (CFU)/g to 8.5×103 CFU/g as determined with the dilution plating technique. The predominant fungi in the mould-contaminated almond samples were Aspergillus niger, A. flavus and the related species, Penicillium, Cladosporium and Rhizopus.
Aflatoxin-producing ability in the isolates of A. flavus and related fungi were tested by thin layer chromatography using 2% yeast extract and 15% sucrose broth culture. Four different aflatoxigenic fungi were detected in the isolates; aflatoxins B1 and B2 were produced by some strains of A. flavus and A. parvisclerotigenus, and aflatoxins B1, B2, G1, G2 were produced by all tested strains of A. parasiticus and A. nomius. Identification of the strains was based on morphological and metabolic characters.View full abstractDownload PDF (2328K) -
Toshio HIDAKA, Keiko ISHII, Tadashi KIRIGAYA, Hiroshi KANDA2007 Volume 48 Issue 4 Pages 97-105
Published: August 25, 2007
Released on J-STAGE: April 28, 2008
JOURNAL FREE ACCESSPossible intermediates in the formation of chloroform during by the sodium hypochlorite (NaClO) treatment of L-tyrosine were investigated using HPLC and LC/MS. One product showed the same MS characteristics as the substance formed by the NaClO treatment of 4-hydroxybenzyl cyanide (4-HBC), and it was suggested to be m-chloro-4-hydroxybenzyl cyanide (m-C-4-HBC). Since m-C-4-HBC is not commercially available it was synthesized by treating 4-HBC with NaClO, and purified by extraction with ethyl acetate, followed by HPLC on preparative isolation columns, using a column switching method. The product was confirmed to be 3-chloro-4-hydroxybenzyl cyanide (3-C-4-HBC), by means of NMR spectral analysis. When L-tyrosine or 4-HBC was treated with NaClO, 3-C-4-HBC and CHCl3 were generated. When 3-C-4-HBC was treated with NaClO, CHCl3 was generated. Judging from these results, 3-C-4-HBC was confirmed to be an intermediate in the formation of CHCl3 from L-tyrosine.
Thus, the reaction pathway of CHCl3 formation from L-tyrosine treated with NaClO is concluded to be: L-tyrosine→4-HBC→3-C-4-HBC→CHCl3.View full abstractDownload PDF (1083K)
Note
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Naoki SUGIMOTO, Atsuko TADA, Takashi YAMAZAKI, Kenichi TANAMOTO2007 Volume 48 Issue 4 Pages 106-111
Published: August 25, 2007
Released on J-STAGE: April 28, 2008
JOURNAL FREE ACCESSRumput roman extract is used as a natural food preservative. Its antimicrobial activity and constituents were investigated as part of an ongoing study to evaluate its quality and safety as a food additive. The constituents were analyzed by GC/MS, and 5 major constituents were isolated and identified as capillin, capillene, caryophyllene oxide, α-curcumene and methyleugenol using NMR analysis. The antimicrobial activities against E. coli, S. cerevisiae and A. niger were measured by means of the halo test. Based on the results, we confirmed that capillin was the major active constituent. The concentrations of capillin and capillene were determined to 17.9 mg/mL and 36.1 mg/mL, respectively, from standard curves of authentic compounds on HPLC.View full abstractDownload PDF (529K)
Reports
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Kenji IIDA, Yoko UEMATSU, Kumi SUZUKI, Tetsuko YASUNO, Keiko HIRATA, K ...2007 Volume 48 Issue 4 Pages 112-117
Published: August 25, 2007
Released on J-STAGE: April 28, 2008
JOURNAL FREE ACCESSProperties of eight commercial licorice extracts used as a food additive (sweetener, listed in the List of Existing Food Additives in the Japanese Food Sanitation Law) were surveyed. Residue on ignition ranged from 0.3 to 12.4%, and pH ranged from 4.1 to 6.8, amount of glycyrrhizin, which is the major component in licorice extract, ranged from 10.9 to 77.4%, sodium ranged from 0.1 to 1.2%, potassium ranged from 0.3 to 5.0%, and ammonium nitrogen ranged from 0.03 to 2.5%. These results indicated that various products were distributed on the market. Differences in the manufacturing process may contribute to the variations of product properties.View full abstractDownload PDF (700K) -
Yoshimichi FUJIMOTO, Kenichi UCHIDA, Makoto OYAIZU, Yonekazu HAMANO2007 Volume 48 Issue 4 Pages 118-123
Published: August 25, 2007
Released on J-STAGE: April 28, 2008
JOURNAL FREE ACCESSThe differences among the small spines of 6 species of puffers have been clarified by means of microscopic observation. Small spines of puffers arise from the basement, which is composed of spines protruding from the surface skin, with roots extending horizontally in all directions in the layer under the surface skin. Using the characteristic shapes of the basement, we have classified the puffer group of “Sansaifugu” (Takifugu flavidus) and “Mefugu” (T. obscurus) as Type I and the group of “Shirosabafugu” (Lagocephalus wheeleri), “Kurosabafugu” (L. gloveri), “Dokusabafugu” (L. lunaris) and “Motosabafugu” (L. spadiceus) as Type II. The number of fore and back roots, including the branches at the ends, further varies in each group. The length and width of each root were measured. As a result, similar species within the group comprising “Sansaifugu” (T. flavidus) and “Mefugu” (T. obscurus) and 4 species of the “Sabafugu” (Lagocephalus) group including “Dokusabafugu” (L. lunaris) have been clearly distinguished. We conclude that examination of the shape of the basement of small spines can be an effective identification index.View full abstractDownload PDF (1053K)
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