Takaharu Kameoka

Mid-infrared spectroscopic measurement of ionic dissociative materials in the metabolic pathway.

We determine the pH dependency of the mid-infrared spectra in aqueous solution of the organic dissociative materials in the metabolic pathway: saccharide phosphates (G6P, F6P), adenosine, and its phosphates (ATP, ADP, AMP). The series of molar absorbance spectra for these reagents were obtained in a pH range of about 2 to 11 with a Fourier transform infrared (FT-IR) spectrometer equipped with a horizontal diamond attenuated total reflection (ATR) sampling accessory. We also provide a method of infrared spectral extraction of ionic dissociative materials by performing a linear least-square fitting utilizing the formulas of ionic dissociation equilibrium shift, and we obtain the infrared spectrum of each ionic species of the dissociative materials: G6P−, G6P2−; F6P−, F6P2−; ATP2−, ATP3−, ATP4−; ADP−, ADP2−, ADP3−; AMP, AMP−, AMP2−; and adenosine+, adenosine0. The infrared spectral structure of each ionic species of the dissociative materials in the metabolic pathway are discussed. Additionally, the possibility for a quantification system of the concentrations of the organic dissociative materials in varying pH is suggested.

Mid-Infrared Spectroscopic Determination of Sugar Contents in Plant-Cell Culture Media Using an ATR Method

A simple, rapid, and accurate method for determining sugar contents in plant-cell culture media by mid-infrared (MIR) spectroscopy was developed by using a Fourier transform infrared (FT-IR) spectrometer equipped with an attenuated total reflectance (ATR) accessory. We examined the potential of this method by comparison with a high-performance liquid chromatography (HPLC) method and applied it to the determination of sugar consumption by plant cells. The cultivation was carried out with Nicotiana tabacum cv. Bright Yellow No. 2 cells. We determined that MIR spectroscopy is at least as useful as the HPLC method for the sugar content determination in the culture medium and may be available to monitor the overall cell metabolisms. This study represents an important step in the development of nonintensive on-line monitoring devices for bioreactors and of simple, rapid, and accurate analysis of the cellular metabolism through the composition changes in media.

Applications of Infrared Spectroscopy to Biochemical, Food, and Agricultural Processes

Abstract Integrated investigations on infrared spectroscopic characteristics of metabolites and on applications of infrared spectroscopy to foodstuff production, food processing, and tasting are described. As the important metabolites, saccharides, which play very important roles in various functions, located in the central position of the metabolic pathways, were selected, and the spectral features of the saccharides and related materials are discussed. Additionally, the applications of spectral analysis to the monitoring of the enzyme reaction and the sugar metabolic processes, which are the main materials in food processing, are described. Furthermore, the studies on the spectroscopic measurements during the cultivation of agricultural products as foodstuffs and in the tasting as the final quality evaluation of foods are represented. These results suggest that infrared spectroscopy could be very effective for evaluating foodstuff production and the tasting of the processed foods and that the applied topics should provide fundamental information about the spectral behavior of the metabolites and bioproducts.

EFFECT OF INFRARED IRRADIATION ON DRYING CHARACTERISTICS OF WET POROUS MATERIALS

ABSTRACT We studied infrared drying characteristics of wet porous materials by comparison with the convective drying characteristics, and our attention was focused on the factors influencing their characteristics. By selecting three kinds of membrane filters, we examined the influences of the mean pore diameter and the spectral distribution of irradiation power as variables using a far-infrared heater and a near-infrared heater. The differences between the infrared and convective drying characteristics (drying rate, sample temperature, water content distribution) were experimentally obtained, and the influence of mean pore diameter of the sample on its drying characteristics was observed only in infrared drying but in convective drying. By measuring the diffuse transmittance of the membrane filter in consideration of the drying process, we deliberated that infrared radiation penetrating into the drying sample was absorbed directly by the water in the voids, and that the water vaporized there.

Influences of Monosaccharides and its Glycosidic Linkage on Infrared Spectral Characteristics of Disaccharides in Aqueous Solutions

The infrared spectral characteristics of ten different types of disaccharides (trehalose, kojibiose, nigerose, maltose, isomaltose, trehalulose, sucrose, turanose, maltulose, and palatinose) and five different types of monosaccharides (glucose, mannose, galactose, talose, and fructose) in aqueous solutions (H2O and D2O) were determined. The infrared spectra were collected using the Fourier transform infrared attenuated total reflectance (FT-IR/ATR) method and comparisons between the degrees of absorption band-shift of the saccharide spectra in the H2O solution with those in the D2O solution with respect to the saccharide concentrations were done. The study revealed that the wavenumber shifts in the bands of mono- and disaccharides in the H2O and D2O solutions could be used as an indicator of the level of interaction between the saccharides and water. The study also focused on the glycosidic linkage position and the constituent monosaccharides and found that they have a significant influence on the infrared spectroscopic characterization of disaccharides in an aqueous solution.

Sugar metabolic analysis of suspensions of plant cells using an FT-IR/ATR method.

A simple, rapid and accurate evaluation of the sugar uptake rate of suspended plant cells from culture media was developed with the predicted sugar contents measured by mid‐infrared spectroscopy using a Fourier transform infrared (FT‐IR) spectrometer equipped with an attenuated total reflectance (ATR) accessory. We performed plant cell cultivation with Nicotiana tabacum cv. Bright Yellow No.2 (TBY‐2) in culture media, which had various combinations of glucose, fructose and sucrose concentrations at the initial stage, and measured simultaneously each sugar content in the medium by the FT‐IR/ATR method. By applying a logistic function to the predicted sugar contents and cell density in the medium during cultivation, the specific sugar uptake rates by the suspended TBY‐2 cells were easily and continuously obtained. Thus the kinetic sugar uptake phenomena by the TBY‐2 cells were well confirmed overall using the developed method. Additionally it was found that the fraction of sucrose of the initial total sugar content might kinetically affect the sugar uptake process and cell growth. Also, the relationship between the nondimensional cell density and sucrose content could be classified into three groups on the basis of the initial fraction of sucrose.

Field Server Projects

A field server is a sensor node which can create a wireless sensor network and simultaneously serve as Wi-Fi hotspots in open fields. Since 2001, we have been working on several Research and Development projects to develop field server technology and its applications. So far, three generations of field servers have been developed and are in use in more than a dozen countries for collaborative research and educational applications such as a global sensor network for Earth observation, food safety/IT-agriculture, advanced sensor technology in fields and image monitoring for urban areas. The field servers have proved to be quite robust for field applications. More work is in progress to develop applications for the field server and resolve issues with power consumption and increasing the communication range for certain applications

X-Ray Fluorescent and Mid-Infrared Spectroscopic Analysis of Tomato Leaves

This study aims to develop a simple, rapid, simultaneous and quantitative method for evaluating nutrimental elements of the plant vigor using X-ray fluorescent (XRF) and mid-infrared (MIR) spectroscopy. Tomato, which is one of the typical agricultural products cultivated by hydroponics, was used as the sample, and the leaves would be an index of the nutrimental conditions. We developed the quantitative methods to analyze the XRF and MIR spectroscopic information, and studied the effects of the cultivation conditions on the nutrient information between branches of a trunk. The experimental results presented a great potentiality to obtain the nutrient information on the chemical elements such as Ca and the organic components such as the nitrogen in the plural modes using the both spectroscopic methods. This study presents an important step in the development of XRF and MIR spectroscopic analysis of the plant vigor in the agricultural fields

Strawberry cultivar identification and quality evaluation on the basis of multiple fruit appearance features

Display Omitted We developed an image analysis system to evaluate the appearances of strawberries.The developed system could simultaneously evaluate multiple appearances in detail.The system could sort/classify strawberries based on the multiple appearances.Combining the multiple appearances improved the accuracy of cultivar identification.Our system provides a new method for phenotyping may contribute to breeding programs. The appearances of agricultural products are important indices for evaluating the quality of commodities and the characteristics of different varieties. In general, the appearances are evaluated by experts based on visual observations. However, the concern regarding this method is that it lacks objectivity, and it is not quantifiable because it depends greatly on an empirical knowledge. In addition, agricultural products have multiple appearance features; therefore, several of them need to be analyzed simultaneously for correct evaluation of the appearance. In this study, we developed a new image analysis system that can simultaneously evaluate multiple appearance characteristics such as the color, shape and size, of agricultural products in detail. To evaluate the effectiveness of this system, we conducted quality evaluations and cultivar identification on the basis of cluster analysis, multidimensional scaling and discriminant analysis of the appearance characteristics. The results of the cluster analysis revealed that strawberries could be classified on the basis of their appearance characteristics. Furthermore, we were able to visualize the small differences in the appearance of the fruit based on multiple characteristics on a two-dimensional surface by performing multidimensional scaling. The results demonstrate that our system is effective for qualitative evaluations of the appearance of strawberries. The results of the discriminant analysis revealed that the accuracy of strawberry cultivar classification using 14 cultivars was <42%, when only single feature was used. However, the rate increased to 68% after combining the three features. These results indicate that our system exploits the advantage of analyzing multiple appearance characteristics.

Mid-Infrared Spectroscopic Analysis of Sugar Metabolism by Rice Cells Suspending in Culture Medium

Abstract A simple, rapid and accurate method for analyzing sugar metabolic and alcohol production kinetics of suspension plant cells was developed by mid-infrared spectroscopy using a Fourier transform infrared spectrometer equipped with an attenuate total reflection accessory. Additionally the sugar metabolic kinetics was studied by focusing our attention on sugars as carbon sources in media at cultivation. Thus the relationship between the kinetic sugar uptake phenomena and alcohol production rate was well confirmed.