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Volume 47 (2006)
- Issue 6 Pages 243-
- Issue 5 Pages 201-
- Issue 4 Pages 137-
- Issue 3 Pages 89-
- Issue 2 Pages 33-
- Issue 1 Pages 1-
Volume 47, Issue 3
Displaying 1-8 of 8 articles from this issue
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Originals
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Shinji KANNO, Yoko KAWAMURA, Motoh MUTSUGA, Kenichi TANAMOTO2006 Volume 47 Issue 3 Pages 89-94
Published: June 25, 2006
Released on J-STAGE: August 04, 2008
JOURNAL FREE ACCESSA determination method was developed for epoxidized soybean oil (ESBO) and epoxidized linseed oil (ELO), which are used as plasticizers and/or stabilizers, in wrapping film and cap sealings. The ESBO method reported by Castle et al. was improved. Samples were extracted with acetone-hexane (3 : 7), transmethylated under alkaline conditions, then derivatized to the 1,3-dioxolanes and analyzed by GC/MS. The recoveries of spiked ESBO and ELO were between 92.6% and 104.4%. The determination limits were 0.01 mg/g for ESBO and 0.02 mg/g for ELO in the wrapping film, and 0.04 mg/g and 0.08 mg/g in the cap sealing. ESBO and ELO were surveyed in 10 samples each of wrapping film and cap sealings currently available on the Japanese market. ESBO was found at 34.7-82.8 mg/g in polyvinyl chloride (PVC) wrapping films and at 5.47-399 mg/g in cap sealings. ELO was detected at 8.6-11.4 mg/g in polyvinylidene chloride (PVDC) wrapping films, and at 46.4 mg/g in a PVC wrapping film.View full abstractDownload PDF (543K) -
Hiroshi FUJIKAWA, Kazuyoshi YANO, Satoshi MOROZUMI2006 Volume 47 Issue 3 Pages 95-98
Published: June 25, 2006
Released on J-STAGE: August 04, 2008
JOURNAL FREE ACCESSCharacteristics of the growth kinetics of Escherichia coli cells in pouched mashed potatoes under various conditions were studied with a mathematical model. Bacterial cells were inoculated in sterile mashed potatoes and then sealed in vinyl pouches, in which a very small amount of air was included. The growth curves of cells in the pouched mashed potatoes at constant temperature (12-34°C) were sigmoidal with time on a semi-logarithmic plot and were successfully described with a new logistic model recently developed by us. The rate constant of growth showed a highly linear relationship to the temperature with the square-root model, and the lag period was longer at lower temperatures. The growth curve in glass tubes containing a large volume of air was similar to that in pouches, showing that the rate of growth was not affected by the volume of the surrounding air. The growth curves in pouched mashed potatoes were very similar to those in nutrient broth or on the surface of nutrient agar, which we previously reported. These results suggested that the growth kinetics of the bacterial cells under various conditions of rich nutrition might be almost identical, and can be described with a simple growth model like ours.View full abstractDownload PDF (174K) -
Asako OZAKI, Chie KAWASAKI, Yoko KAWAMURA, Kenichi TANAMOTO2006 Volume 47 Issue 3 Pages 99-104
Published: June 25, 2006
Released on J-STAGE: August 04, 2008
JOURNAL FREE ACCESSMigration of bisphenol A (BPA) and benzophenones, i.e., benzophenone (BZ), 4-(dimethylamino)benzophenone (DMAB), Michler's ketone (MK) and 4,4'-bis(diethylamino)benzophenone (DEAB), from 21 paper and paperboard products (15 recycled paperboard boxes and 6 virgin paper products) used in contact with food was examined. Migration levels of compounds from recycled paperboard were compared under various food-simulating conditions. BPA showed the highest migration into 20% ethanol and benzophenones into 95% ethanol. No compounds migrated from virgin paper products, but compounds did migrate into food simulants from recycled paperboard food boxes. BPA migrated into 20% ethanol from all recycled paperboard food boxes between 1.0 and 18.7 ng/mL. Into 95% ethanol, migration of BZ was observed in 8 samples (1.0-18.9 ng/mL), DMAB in 12 samples (1.2-3.7 ng/mL), MK in 13 samples (1.9-9.0 ng/mL), and DEAB in 13 samples (1.0-10.6 ng/mL). The highest migration level was 27.2 ng/mL and most of the migration levels were below 10 ng/mL. These values are sufficiently low compared with the TDI and NOAEL levels. Moreover, the amount of food in daily meals that comes into contact with paperboard products is relatively small. Consequently, it was concluded that there was no safety concern regarding the tested compounds in recycled paperboard food boxes.View full abstractDownload PDF (499K) -
Yasuo TANAKA, Kyoko TAKAHASHI, Tadashi KIRIGAYA, Shiro HOSOI, Toshio H ...2006 Volume 47 Issue 3 Pages 105-110
Published: June 25, 2006
Released on J-STAGE: August 04, 2008
JOURNAL FREE ACCESSA peak considered to be due to disulfoton sulfoxide as a metabolite of disulfoton was detected in the analysis of the chingentsuai extraction solution of vegetables by GC-FPD.
In the analysis by GC/MS for identification, though the retention time and the mass spectrum were the same as those of the standard, the spectrum was different from MS library data. It appeared that decomposition of disulfoton sulfoxide occurred at the inlet.
Therefore, we used a programmed temperature vaporization (PTV) inlet in the pulsed splitless mode to achieve a low inlet temperature and high injection pressure. As a result, the expected mass spectrum of disulfoton sulfoxide was obtained. Under this condition, the peak obtained from chingentsuai was identified as disulfoton sulfoxide. Disulfoton sulfoxide was detected from 2 of 25 chingentsuai samples, at concentrations of 0.66 μg/g and 0.14 μg/g.View full abstractDownload PDF (572K)
Notes
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Hiroshi AKIYAMA, Takahiro WATANABE, Hiroyuki KIKUCHI, Kozue SAKATA, Sh ...2006 Volume 47 Issue 3 Pages 111-114
Published: June 25, 2006
Released on J-STAGE: August 04, 2008
JOURNAL FREE ACCESSWe examined the lateral flow strip assay for identifying unauthorized genetically modified (GM) rice. The GM rice expresses the Bacillus thuringiensis (Bt) toxin, CryIAc protein, which confers tolerance to insects. The recombinant CryIAc protein was prepared from the inclusion bodies of an E. coli. strain into which the CryIAc gene had been inserted, using gel filtration chromatography. The lateral flow strip assay for the identification of GM cotton which also expresses CryIAc protein, was applied to unpolished rice and polished rice spiked with recombinant CryIAc protein. The spiked recombinant CryIAc protein was clearly detected at the level of 0.012 μg/g in both the unpolished and polished rice. After loading of the extract on the strip, a 60-minute stand time is necessary to clearly detect CryIAc protein. The detection limit was approximately 12 ng CryIAc protein per gram of rice. These results suggest that the lateral flow strip assay for GM cotton can be used to detect CryIAc protein expressed in GM rice.View full abstractDownload PDF (475K) -
Hiroshi FUJIKAWA, Kazuyoshi YANO, Satoshi MOROZUMI2006 Volume 47 Issue 3 Pages 115-118
Published: June 25, 2006
Released on J-STAGE: August 04, 2008
JOURNAL FREE ACCESSWe recently studied the growth characteristics of Escherichia coli cells in pouched mashed potatoes (Fujikawa et al., J. Food Hyg. Soc. Japan, 47, 95-98 (2006)). Using those experimental data, in the present study, we compared a logistic model newly developed by us with the modified Gompertz and the Baranyi models, which are used as growth models worldwide. Bacterial growth curves at constant temperatures in the range of 12 to 34°C were successfully described with the new logistic model, as well as with the other models. The Baranyi gave the least error in cell number and our model gave the least error in the rate constant and the lag period. For dynamic temperature, our model successfully predicted the bacterial growth, whereas the Baranyi model considerably overestimated it. Also, there was a discrepancy between the growth curves described with the differential equations of the Baranyi model and those obtained with DMfit, a software program for Baranyi model fitting. These results indicate that the new logistic model can be used to predict bacterial growth in pouched food.View full abstractDownload PDF (171K)
Reports
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Yukiko KUDO, Yoichi ONOUE, Hiroshi NAKAGAWA, Atsuko TAKAHASHI, Noriko ...2006 Volume 47 Issue 3 Pages 119-126
Published: June 25, 2006
Released on J-STAGE: August 04, 2008
JOURNAL FREE ACCESSFrom January to November, 2003, bacterial contamination was surveyed in a small egg-breaking factory that produced non pasteurized liquid egg. Test egg samples were taken at various stages of the egg processing operation. Salmonella Enteritidis was isolated from liquid egg yolk and liquid egg white on October, but was not found in any other samples (50 liquid egg samples, 21 containers and 94 attached production facilities and gloves). The data suggest that the contamination rate (3.8%) is lower than those reported previously. Levels of bacterial standard plate counts, gram-positive bacterial counts and gram-negative bacterial counts were in the ranges of 2 to 5 log CFU/g, 2 to 3 log CFU/g, 2 to 5 log CFU/g, respectively. Liquid egg containers returned from customers was contaminated with bacteria at the level of 8 log CFU per container. However, washing and application of a sanitizer containing sodium hypochlorite reduced the bacterial counts.View full abstractDownload PDF (2080K) -
Hisashi MATSUMOTO, Katsuyoshi KUWABARA, Yasuyuki MURAKAMI, Hiroshi MUR ...2006 Volume 47 Issue 3 Pages 127-135
Published: June 25, 2006
Released on J-STAGE: August 04, 2008
JOURNAL FREE ACCESSResidues of PCB and organochlorine pesticides in meats (beef, pork and poultry) and processed meat products collected in Osaka, Japan were surveyed. For 35 years from 1970 to 2004, the concentrations of PCB, HCH isomers, DDT analogues and dieldrin in all meats appeared to decline with each passing year. The concentration of each isomer of HCH in all meats declined rapidly from the early to the late 1970's and showed a gentle decline thereafter; β-HCH showed the highest residue rate of the isomers in all the time periods surveyed, except for pork and poultry samples in the early 1980's. The concentrations of DDT analogues in all meats also showed sharp declines from the late 1970's to the early 1980's, followed by a smaller decrease thereafter; the main residues were p,p'-DDD, p,p'-DDE and p,p'-DDT, and the residue rate of p,p'-DDE increased over the years. The residue levels of organochlorine pesticides in processed meat products (raw materials: beef, pork, poultry and mixture of ground beef and pork) were surveyed for 15 years (from 1990 to 2004) and there were no significant differences in the values among the materials. The concentrations of each pesticide in processed meat products tended to be lower than those of the corresponding meat samples, respectively.View full abstractDownload PDF (598K)
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