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Ibaraki, Japan

Mizuochi S.,Nissui Pharmaceutical Co. | Nelson M.,Nelson Consulting
Journal of AOAC International

Nissui Compact Dry YM was originally certified by the AOAC Research Institute Performance Tested MethodsSM (PTM) program (PTM No. 100401) for enumeration of yeasts and molds in fruit products after 7 days of incubation. A matrix extension study, organized by Campden BRI (Chipping Campden, United Kingdom), was conducted to extend the method's claim to cooked deli Turkey, fresh whole tomatoes, cheese (Wensleydale), sliced white bread, and mayonnaise. In addition, the method was evaluated at 3 and 7 days to validate the 3 day incubation period. Compact Dry YM is a readyto- use dry media sheet, containing a cold-soluble gelling agent, selective agents, and chromogenic medium, which are rehydrated by adding 1 mL diluted sample. Yeasts and molds appear as blue colonies, while molds can also have a cottony appearance and the color may vary. Users can obtain total yeast and mold count following 3-7 days of incubation at 25 ± 1°C. Method comparison data for cooked deli Turkey, fresh whole tomatoes, cheese (Wensleydale), sliced white bread, and mayonnaise were collected in a single-laboratory evaluation by Campden BRI. A multilaboratory study was conducted on orange juice with 10 laboratories participating including the organizing laboratory. Compact Dry YM was compared to ISO 21527-1:2008, Microbiology of food and animal feeding stuffs- Horizontal method for the enumeration of yeasts and molds - Part 1: Colony count technique in products with water activity greater than 0.95, the current standard at the time of this study. Each matrix was evaluated for total yeasts and molds at each contamination level (including an uncontaminated level). In the single-laboratory evaluation (cooked deli Turkey, fresh whole tomatoes, cheese, sliced white bread, and mayonnaise), colony counts were logarithmically transformed, and then the data were analyzed at each level for repeatability (sr), RSD of repeatability (RSDr), and mean difference between methods with a 95% confidence interval (CI). A CI outside a range of (-0.5 to 0.5) on the log10 mean difference between methods was used as the criterion to establish a significant statistical difference. In the multilaboratory study on orange juice, after logarithmic transformation the data were analyzed for sr, RSDr, and mean difference with 95% CIs and also for reproducibility (sR) and RSD of reproducibility (RSDR). Regression analysis was performed on all matrixes and reported as r2. Results from Compact Dry YM at 3 and 7 days were compared separately to ISO 21527-1 and then to each other. In the single-laboratory evaluation, five contamination levels were tested. With the exception of cheese, there were few, if any, colonies recovered at the two lowest contamination levels. As a consequence, differences of a few colonies resulted in significant statistical differences indicated between Compact Dry YM (at both 3 and 7 days) and ISO 21527-1 for most of the foods at these levels. At the three higher contamination levels, statistical differences were seen between Compact Dry YM at 3 days and the ISO method for cooked deli Turkey at the middle level, tomatoes at the two middle levels, sliced white bread at the two highest levels, and mayonnaise at the middle level. After 7 days, statistical differences remained between Compact Dry and ISO methods, based on the CIs, but mean differences between methods were <0.5 log10 CFU/g for all foods at the three highest contamination levels. When comparing results between Compact Dry YM at 3 and 7 days, statistical differences were indicated for tomatoes and sliced white bread, both in the second highest contamination level. Otherwise, differences between results at 3 and 7 days were small. The sr and RSDr values were similar for Compact Dry YM (both days) and ISO 21527-1, and r2 values were ≥0.84 for all comparisons. In the multilaboratory study for orange juice, there were no statistical differences between methods across 11 data sets. Four contamination levels were tested, and at all levels mean differences between methods were <0.1 log10 CFU/mL, and CIs were smaller than (-0.05, 0.15), well within the acceptance criterion of (-0.5, 0.5). The sr, RSDr, sR, and RSDr were similar for each method, and r2 was 1.0 in all comparisons. Results indicate that Compact Dry YM offers comparable results at 3 days to the ISO standard plating method at 5 days, in a space-saving, easy-to-use format. Source

Yoshie S.,Shinshu University | Shirasawa S.,Bourbon Corporation | Yokoyama T.,Bourbon Corporation | Kanoh Y.,Shinshu University | And 5 more authors.
Biochemical and Biophysical Research Communications

To establish an effective induction method for hepatic differentiation using serum-free media, the effects of activin in serum-containing and serum-free conditions on embryoid body (EB) induction into mesendoderm were investigated by Western blot analysis and real-time reverse transcription-polymerase chain reaction (RT-PCR) as a first step. The expression of P-smad2 and mesendodermal markers was markedly enhanced by 100 ng/ml activin under serum-free conditions but were inhibited or masked under serum-containing conditions. Next, serum-free Lanford medium was used to attempt the direct induction of activin-treated EBs expressing mesendodermal markers into hepatic lineage cells and this induction was compared to that induced using Iscove's Modified Dulbecco's medium containing 20% fetal bovine serum. Once immersed in the Lanford medium, EBs began to show typical hepatic features by day 17, including Alb, AFP, TTR, and AAT expression detected by RT-PCR, and ALB, AFP, and CK18 expression detected by immunostaining. On day 22, these cells were of high quality characterized by the expression of metabolizing enzymes, including Ugt1a1, Slcola4, cyp3a11, cyp2b10, and cyp7a1 detected by real-time PCR, a 50-fold greater cyp3A11 response than control to 100 μM dexamethasone stimulation, specific cellular uptake of indocyanine green, and glycogen storage in the cytoplasm. These results indicate that this simple two-step induction method under serum-free conditions induces hepatic lineage cells with high quality directly from mouse embryonic stem (ES) cell-derived mesendoderm. © 2009 Elsevier Inc. All rights reserved. Source

Shibahara Y.,Nissui Pharmaceutical Co. | Uesaka Y.,Nissui Pharmaceutical Co. | Wang J.,Nippon Suisan Kaisha Ltd. | Yamada S.,Nippon Suisan Kaisha Ltd. | Shiomi K.,Tokyo University of Marine Science and Technology
Food Chemistry

Fish is one of the most common causes of food allergy and its major allergen is parvalbumin, a 12 kDa muscular protein. In this study, a sandwich enzyme-linked immunosorbent assay (ELISA) for the determination of fish protein in processed foods was developed using a polyclonal antibody raised against Pacific mackerel parvalbumin. The developed sandwich ELISA showed 22.6-99.0% reactivity (based on the reactivity to Pacific mackerel parvalbumin) to parvalbumins from various species of fish. The limits of detection and quantitation were estimated to be 0.23 and 0.70 μg protein per g of food, respectively. When the sandwich ELISA was subjected to inter-laboratory validation, spiked fish protein was recovered from five model processed foods in the range of 69.4-84.8% and the repeatability and reproducibility relative standard deviations were satisfactorily low (≤10.5%). Thus, the sandwich ELISA was judged to be a useful tool to determine fish protein in processed foods. © 2012 Elsevier Ltd. All rights reserved. Source

Shibahara Y.,Nissui Pharmaceutical Co. | Ii T.,Nissui Pharmaceutical Co. | Wang J.,Nippon Suisan Kaisha Ltd. | Yamada S.,Nippon Suisan Kaisha Ltd. | Shiomi K.,Tokyo University of Marine Science and Technology
Journal of the Food Hygienic Society of Japan

The major fish allergen is parvalbumin, a sarcoplasmic protein. In this study, a novel lateral flow immunoassay for the detection of fish protein in food products was developed using a polyclonal antibody raised against Pacific mackerel Scomber japonicus parvalbumin. The proposed lateral flow immunoassay showed high reactivity to various fish parvalbumins, but the reactivity to bullfrog parvalbumin was very low. The detection limit of the immunoassay for fish parvalbumin was estimated to be 2.0 μg protein/g, which matches the sensitivity required in the current Japanese food labeling system. Furthermore, the lateral flow immunoassay could detect fish parvalbumin without being affected by food matrices and was applicable even to heat-denatured parvalbumin. These results showed that the lateral flow immunoassay developed in this study is specific to fish parvalbumin, and should be useful as a rapid detection method for fish protein in processed food products. Source

Teramura H.,Nissui Pharmaceutical Co. | Uchida M.,Nissui Pharmaceutical Co. | Kodaka H.,Nissui Pharmaceutical Co.
Biocontrol Science

We evaluated the effectiveness of using Compact DryR X-BC (CD-XBC), a ready-to-use and self-diffusing dry medium sheet culture system based on a novel detection principle, for the detection and enumeration of Bacillus cereus. All 13 B. cereus strains, which were studied for the inclusivity study, grew as blue/green colonies on the CD-XBC. When 3 yeast strains and 103 bacterial strains other than B. cereus were tested for the exclusivity study, 5 strains formed white colonies, and 4 strains formed blue/green colonies, while 94 other strains failed to grow. The 4 strains that formed blue/green colonies were B. thuringiensis, which is known to have the same biochemical features as B. cereus. The CD-XBC method was compared with the MYP agar method (MYP) and the NGKG agar method (NGKG) in 130 artificially contaminated food samples. The correlation coefficients between CD-XBC and MYP, and CD-XBC and NGKG were 0.972 and 0.971, respectively. Source

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