Koseki S.,Japan National Food Research Institute |
Nonaka J.,Nisshin Seifun Group Inc.
Applied and Environmental Microbiology | Year: 2012
The objective of this study was to develop a probabilistic model to predict the end of lag time (λ) during the growth of Bacillus cereus vegetative cells as a function of temperature, pH, and salt concentration using logistic regression. The developed λ model was subsequently combined with a logistic differential equation to simulate bacterial numbers over time. To develop a novel model for λ, we determined whether bacterial growth had begun, i.e., whether λ had ended, at each time point during the growth kinetics. The growth of B. cereus was evaluated by optical density (OD) measurements in culture media for various pHs (5.5 ∼ 7.0) and salt concentrations (0.5 ∼ 2.0%) at static temperatures (10 ∼ 20°C). The probability of the end of λ was modeled using dichotomous judgments obtained at each OD measurement point concerning whether a significant increase had been observed. The probability of the end of λ was described as a function of time, temperature, pH, and salt concentration and showed a high goodness of fit. The λ model was validated with independent data sets of B. cereus growth in culture media and foods, indicating acceptable performance. Furthermore, the λ model, in combination with a logistic differential equation, enabled a simulation of the population of B. cereus in various foods over time at static and/or fluctuating temperatures with high accuracy. Thus, this newly developed modeling procedure enables the description of λ using observable environmental parameters without any conceptual assumptions and the simulation of bacterial numbers over time with the use of a logistic differential equation. © 2012, American Society for Microbiology. All Rights Reserved. Source
Nisshin Seifun Group Inc. | Date: 2014-02-25
Provided is a method of detecting or quantifying a wheat species-specific DNA in a test sample by polymerase chain reaction. The method comprises a step of amplifying a nucleic acid molecule having at partial sequence of a nucleotide sequence identified as SEQ ID NO: 1 using a nucleic acid molecule in the test sample or a nucleic acid molecule extracted from the test sample as the template and using a primer pair capable of amplifying the partial sequence and a step of detecting or quantifying the amplified nucleic acid molecule.
Nisshin Seifun Group Inc. | Date: 2012-02-24
A powder-classification method includes a mixing step in which a powder and a liquid additive are mixed together, a drying step in which the powder mixed in the mixing step is dried, a loading step in which the powder dried in the drying step is loaded into a fluid classifier, a heating step in which a gas is heated, a supplying step in which the gas heated in the heating step is supplied to the fluid classifier, and a classifying step in which the powder is classified in the fluid classifier based on a grain size of the powder.
Nisshin Seifun Group Inc. and Nisshin Engineering Inc. | Date: 2014-01-22
This method for producing magnetic particles comprises a nitriding treatment step for applying a nitriding treatment to material particles each having a core-shell structure in which an aluminum oxide layer is formed on the surface of an iron microparticle, and nitriding the iron microparticles while maintaining the core-shell structure.
Japan National Institute of Advanced Industrial Science, Technology, Nisshin Seifun Group Inc. and Oriental Yeast Co. | Date: 2015-04-01
Disclosed are a method of preparation and method of application of a circadian rhythm regulatory agent having as an active ingredient an alkylresorcinol represented by general formula (I) below and a circadian rhythm regulatory agent containing as an active ingredient an alkylresorcinol-containing extract from a cereal or a nut containing an alkylresorcinol of the following general formula (I). In the following general formula (I), R