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Hoyoku NISHINO
1998 Volume 39 Issue 6 Pages
345-349
Published: December 05, 1998
Released on J-STAGE: December 11, 2009
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Tsuyuji SHIMADA, Masakatsu ICHINOE
1998 Volume 39 Issue 6 Pages
350-356_1
Published: December 05, 1998
Released on J-STAGE: December 11, 2009
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A mycological study was carried out of the fungi occurring in mold-ripened cheese. Samples of cheese were obtained from retail products. Fungi were enumerated by dilution plating on dichloran rose bengal chloramphenicol agar.
In 40 commercial samples examined, including 21 samples of blue-veined cheese and 6 samples of blue-veined cheese covered with white mold fermented soft cheeses.
Penicillium species derived from starter cultures, and
Geotrichum candidum and yeasts as contaminants were recovered.
Fungal counts were reported as numbers of colony-forming units per gram of sample.
Penicillium roqueforti isolates from blue-veined cheese were subdivided into 5 different types based on cultural characteristics, such as color of colony reverse, sclerotia formation and rough stipes on identification on media.
P. camemberti was examined for white cheeses. Other
Penicillium species were also isolated from these cheese samples.
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Yukari TSUMURA, Yumiko NAKAMURA, Kimihiko YOSHII, Yasuhide TONOGAI, Ma ...
1998 Volume 39 Issue 6 Pages
357-367_1
Published: December 05, 1998
Released on J-STAGE: December 11, 2009
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Twenty-one
N-methylcarbamates (NMCs) and 12 metabolites or isomers in agricultural products were simultaneously determined. As extraction was accomplished with ethyl actate instead of dichloromethane, NMCs possessing a thioether group were partly oxidized to sulfoxides. They were quantified as total amount of oxidized and non-oxidized compounds. NMCs in food samples were extracted with acetone, then the acetone was evaporated off and sodium chloride was added before extraction with ethyl acetate. The extract was evaporated and the residue was partitioned between acetonitrile and
n-hexane. The acetonitrile layer was evaporated and the residue was cleaned up on a Sep-Pak
® aminopropyl cartridge. NMCs were determined by HPLC with post-column reaction and fluorescence detection. Recoveries of NMCs from 10 kinds of agricultural products including rice, onion and apple were 56.9 to 108.2%, except for butocarboxim sulfoxide, at fortification levels of 0.1 to 1ppm. Detection limits were 0.01ppm for major NMCs.
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Kyoko SATO, Naoki SUGIMOTO, Shiho SAKAMOTO (SASAKI), Yoshinori YASUI, ...
1998 Volume 39 Issue 6 Pages
368-374_1
Published: December 05, 1998
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HPLC analysis of haematococcus algae color revealed 4 principal pigments which exhibited UV-Vis spectra similar to that of astaxanthin. HPLC analysis of saponified haematococcus algae color and LC/APCI-MS analysis of the haematococcus algae color suggested that the pigments were a group of astaxanthin monoesters. The 4 principal pigments were identified as the astaxanthin monoesters with linolenic, linoleic, oleic, and palmitic acids, by LC/APIC-MS analyses of synthetic esters of astaxanthin with the respective fatty acids.
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Kiyoshi SEKITA, Minoru SAITO, Osayuki UCHIDA, Atsushi ONO, Yukio OGAWA ...
1998 Volume 39 Issue 6 Pages
375-382_1
Published: December 05, 1998
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A subchronic toxicity study of pecan nut color was performed using F344 rats of both genders. Pecan nut color, a flavonoid extrcated from the coat of pecan nuts (
Carya pecan ENGL. et GRAEBN.), is permitted for use as a food color by the Ministry of Health and Walfare, Japan. The product containing 60% dextrin (added in the process of manufacture) was used in the experiment. Rats were administered pecan nut color at concentrations of 0% (basal diet, control group), 0.5%, 3.0% and 5.0% in the basal powder diet for 90 days. Rats in the vehicle control group were given dextrin at the concentration of 3.0% in the same manner as used for the experimental groups. No significant changes related to pecan nut color or dextrin were found in body weight or food consumption throughout the observation period, or in hematology, serum chemistry or organ weights at autopsy. Furthermore, neither gross nor histological examination revealed any adverse effect or significant difference from the control. It is concluded that feeding of diet containing pecan nut color at a concentration of 5.0% (1, 287mg/kg/day for males and 1, 344mg/kg/day for females as mean intake of pecan nut color without dextrin) for 90 days has no adverse effect in rats.
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Masakazu HORIE, Terumitsu YOSHIDA, Koichi SAITO, Hiroyuki NAKAZAWA
1998 Volume 39 Issue 6 Pages
383-389_1
Published: December 05, 1998
Released on J-STAGE: December 11, 2009
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A simple and rapid screening method using HPLC for the simultaneous determination of 13 veterinary drugs (oxytetracycline, quinoxaline-2-carboxylic acid, thiabendazole, 5-hydroxythiabendazole, albendazole-2-aminosulfone, sulfadimidine, flubendazole, zeranol, β-trenbolone, sulfadimethoxine, sulfamonomethoxine, oxolinic aid, and enrofloxacin) in meat and fish has been developed. The drugs were extracted with 0.25% metaphosphoric acidmethanol-acetonitrile (6:2:2, v/v), and the extracts were cleaned up on an OASIS HLB (60mg) cartridge. The HPLC separation was performed on a Wakosil-II-5C18 RS column (150×4.6mm i. d.) with a gradient system of 0.025mol/L phosphate buffer (pH 2.5)-acetonitrile as the mobile phase at a flow rate of 0.6mL/min. The drugs were detected with ultraviolet (UV) and fluorescence detectors with time programming. The calibration graphs were rectilinear from 1 to 20ng for each drug. The recoveries at levels of 0.02-0.1μg/g were 75.1-90.5%.
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Yoko KAWAMURA, Kyoko NISHI, Tamae MAEHARA, Takashi YAMADA
1998 Volume 39 Issue 6 Pages
390-398_1
Published: December 05, 1998
Released on J-STAGE: December 11, 2009
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The migration of styrene dimers and trimers from polystyrene containers into instant foods and their content in the container were determined by GC and GC/MS. Thirty-two kinds of instant foods, which included Chinese noodles, Japanese noodles (udon), buckwheat noodles (soba), chow mein (yakisoba), spaghetti, soup (miso-soup, minestrone, etc.) and rice (gomokumeshi, chuka-don and gruel) were analyzed. In the whole instant foods, the migration levels of the total trimers ranged from undetectable to 62.4ng/g (0-33.8μg/cup) while dimers were not found. In the case of Chinese noodles, the migration into noodles was higher than that into soup and the total migration level at 30 minutes after adding hot water was 1.5 times higher than that at 10 minutes. In the case of Chinese noodles and soup in EPS (expandable polystyrene) containers, the contents of dimers and trimers in the material of the containers were under 800μg/g, and they did not detect in the foods. Raw or non-fried noodles had a lower migration level than fried noodles even in PSP (polystyrene paper) cups which contained more than 4, 800μg/g of dimers and trimers. The migration during microwave oven cooking was somewhat higher than during hot-water cooking.
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Masahiro TERAUCHI, Hisayuki KANAMORI, Masao NOBUSO, Shinji FUKUDA, Sho ...
1998 Volume 39 Issue 6 Pages
399-405_1
Published: December 05, 1998
Released on J-STAGE: December 11, 2009
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Biologically active compounds in leaves of
Lycium chinense (Lycii Folium) were examined to develop the effective use of this plant as a health food. The methanol extract of Lycii Folium exhibited antimicrobial activities, and one of the active compounds was identified as lyciumoside I (
1) which is a characteristic component of
Lycium chinense. Furthermore, the methanol extract of Lycii Folium inhibited the growth of
Helicobacter pylori. The active component against
H. pylori was also identified as
1. Quantitative analyses revealed that
1 was extracted into Kuko tea in high concentration. The hydrolysis products of
1 were also assayed for antimicrobial activity to study their structure-activity relationship.
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Hironari KIRIHARA, Mamoru YOTORIYAMA, Takeshi UEHARA, Kanako KUROSAKI, ...
1998 Volume 39 Issue 6 Pages
406-409_1
Published: December 05, 1998
Released on J-STAGE: December 11, 2009
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Capillary electrophoresis (CE) has been applied to distinguish the species of mushrooms with similar shapes morphologically.
Water-extracts of mushrooms were cleaned up with a Sep-Pak C
18 cartridge using methanol. After evaporation, the residue was dissolved in water and 50mmol/L anhydrous caffeine was added as an internal standard for the analysis by CE. Migration time (MT) of electroosmotic flow (EOF), relative migration (RM) and mobility (μ) on CE-grams were used as indexes for distinguishing the species of mushrooms.
Naematoloma sublateritium and
Naematoloma fasciculare,
Lentinus edodes and
Lampteromyces japonicus and
Rhodophylus rhodopholius and
Rhodophyllus crassipes could be distinguished by this method.
Indexes of numerical values of RM and μ on CE-grams were species-specific, indicating that mushroom species might be identified by analyzing the water-soluble proteins of mushroom.
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Takiko SUGITA, Yoko KAWASAKI, Masahiro NAGATA, Hajimu ISHIWATA, Takash ...
1998 Volume 39 Issue 6 Pages
410-414_1
Published: December 05, 1998
Released on J-STAGE: December 11, 2009
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Polyvinyl acetate (PVAc) has been used in many countries as a masticatory substance in chewing gum base. A method was developed for the determination of residual vinyl acetate monomer (VAcM) in PVAc for chewing gum base. PVAc (2.5g) was dissolved in toluene and the prepared solution was injected into a gas chromatograph equipped with a capillary column coated with DB-1 (0.32mm i. d.×30m, 5μm film thickness) and an FID. The calibration curve of VAcM showed a good linear correlation (
r=0.9998) in the range of 0.19μg/mL-9.6μg/mL. The method was applied to determine VAcM in 12 PVAc samples for chewing gum base. Residual VAcM was found in 6 samples (3-12μg/g). In addition, acetic acid (a raw material) was detected in all samples, and isopropanol and ethyl actate, which are solvents used in the production, were detected in 10 samples.
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Yukihiro GODA, Shinobu SAKAI, Takatoshi NAKAMURA, Kazunari KONDO, Hiro ...
1998 Volume 39 Issue 6 Pages
415-420_1
Published: December 05, 1998
Released on J-STAGE: December 11, 2009
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Seeds of “Moroheiya” (
C. olitorius) contain not only strophanthidin (SP) glycosides, but also digitoxigenin (DG) glycosides. In an earlier paper, we reported that SP glycosides were not detected in fresh “Moroheiya” (including green leaf, green stem, shoot and pod), which is ingested in Japan as a vegetable, in dried health tea products and in health food products. In this report we deal with analysis of DG glycosides in them.
Methanol extracts of edible samples were hydrolyzed in methanol-0.3mol/L HCl (2:1) for 6 days at room temperature. A solution of the hydrolysate in a mixture of hexane-ethyl acetate (1:1) (2mL) was applied to a Bond Elut Silica cartridge. The eluate by 10mL of the solvent mixture was concentrated to dryness and the residue was redissolved in methanol (1mL). Then, 10μL of the solution was subjected to HPLC to determine DG at UV 220nm.
Well-matured seeds and their pods contained DG glycosides at a concentration of 200 and 4μg/g, respectively, as DG. However, DG glycosides, as well as SP glycosides, were not detected in the edible samples.
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Yuichi FUCHI, Kikuo HOASHI, Hiroshi AKAEDA, Yoshihiro MAKINO, Tamao NO ...
1998 Volume 39 Issue 6 Pages
421-425_1
Published: December 05, 1998
Released on J-STAGE: December 11, 2009
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Forty-nine specimens of “Hoshifugu” puffer fish,
Arothron firmamentum (23 male and 26 female specimens) were collected from the Bungo Channel, Oita Prefecture, during 1991 to 1997, and examined for the anatomical distribution and the seasonal variation of toxicity by the mouse assay method.
Skin showed a rather low level of toxicity and the frequency of toxic specimens was 6.1% with the maximal lethal potency of 29 mouse unit (MU)/g. Ovary showed a higher level of toxicity (frequency 80.8%) with the maximal lethal potency of 640MU/g. On the other hand, the muscle, liver, testis and intestine were non-toxic. Ovaries collected in 6 different months (March, May, and August-November) were found to be toxic with the frequency of 50-100%. Skins were found to be toxic in August and October. It appears that this species has high toxicity in the ovary during early summer to autumn.
Since the muscle of “Hoshifugu” puffer fish specimens caught in the Bungo Channel was non-toxic, the muscle of this species appears to be edible without risk to humans.
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Takashi OHURA, Atsushi YAMAMOTO, Shuji KODAMA, Akinobu MATSUNAGA
1998 Volume 39 Issue 6 Pages
426-430_1
Published: December 05, 1998
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A simple and rapid method for determination of imazalil in citrus fruit was developed by HPLC using derivative analysis of spectra. Imazalil was extracted from citrus fruit with acetonitrile under alkaline conditions and the extract was concentrated to dryness. The residue was dissolved in 10mmol/L KH
2PO
4-acetonitrile (2:3) and filtered through a 0.45μm membrane filter. The sample solution thus prepared was subjected to HPLC with photodiodearray (PDA) detection. The first to fourth-order derivative spectra, that have characteristic maxima and minima, were calculated from imazalil spectra data recorded with the PDA. By plotting the first to fourth-order derivative values at the above maxima and minima from sample spectral data against analysis time, several derivative spectrum chromatograms were obtained. We found that imazalil in samples could be determined from only third-order derivative spectrum chromatograms at 213 and 233nm. The recoveries of imazalil in citrus fruits fortified at 1μg/g and 4μg/g were 89.8-90.1% and 91.9-93.3%, respectively. The proposed method was applied to the analysis of commercially available citrus fruits. Imazalil contents thus determined agreed well with these obtained by the official method. The lower limit of determination of imazalil in citrus fruit was found to be 0.5μg/g.
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Tadashi TSUKIOKA, Tetsuya YOSHIDA, Moritoshi SATO
1998 Volume 39 Issue 6 Pages
431-435_1
Published: December 05, 1998
Released on J-STAGE: December 11, 2009
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An analytical method by GC/MS has been established for the herbicide difenzoquat in cereals. Difenzoquat was extracted with acetone, concentrated with a rotary evaporator, and applied to an Extrelut 20 column. The column was washed with
n-hexane, eluted with ethyl acetate containing 4% formic acid, and concentrated. The residue was dissolved in 0.1mol/L NaOH solution, adsorbed on an ODS mini column, washed with 50% methanol, and eluted with ethyl acetate containing 4% formic acid. The elute was concentrated and analyzed by GC/MS. This method gave a recovery of over 80% with a C. V. below 6% and a detection limit of 1μg/kg. This method, with excellent sensitivity and selectivity, should be useful as a routine analytical method for cereals.
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Hirokazu OGIHARA, Takahiro HITOMI, Nobuhiro YANO
1998 Volume 39 Issue 6 Pages
436-439_1
Published: December 05, 1998
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Effects of intensity of high hydrostatic pressure and its duration on the inactivation of
Aeromonas hydrophila,
Escherichia coli,
Pseudomonas aeruginosa,
Salmonella Enteritidis,
S. Typhimurium, and
Staphylococcus aureus in phosphate buffer were investigated.
Among the strains examined,
A. hydrophila was most susceptible to pressure, and a 6D decrease of viable count with 10
8CFU/mL cell suspension was observed after exposure to 250MPa for 10min. To obtain the same reduction of viable count,
P. aeruginosa,
E. coli,
S. Typhimurium, and
S. Enteritidis had to be treated for 250MPa·30min, 300MPa·30min, 400MPa·10min, and 400MPa·10min, respectively.
S. aureus was the most resistant to pressure, and survivors were observed after 600MPa·30min. The results suggest that each strain has a specific pressure region where inactivation proceeds rapidly with increase of both pressure and duration of the process.
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Susumu HIRANO, Noriyuki OKAWARA, Makoto ONO
1998 Volume 39 Issue 6 Pages
440-443_1
Published: December 05, 1998
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Setsuko TABATA, Akihiro IBE, Hideki OZAWA, Hisashi KAMIMURA, Kazuo YAS ...
1998 Volume 39 Issue 6 Pages
444-447_1
Published: December 05, 1998
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Kumiko SASAKI, Yumiko NAKAMURA, Takahiro NINOMIYA, Toshitsugu TANAKA, ...
1998 Volume 39 Issue 6 Pages
448-452_1
Published: December 05, 1998
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