researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

Shades are adjusted in sweet pepper cultivation, based on solar exposure levels. Pyranometers and photosensitive films have recently been introduced to smart agriculture. However, there are no means of observing biological responses to solar exposure. In this study, we hypothesized that solar exposure levels affect the visible autofluorescence of sweet pepper under 365 nm illumination. To test this hypothesis, we cultivated sweet pepper plants under two exposure conditions, low (half of the normal) and high (the normal). Fluorescence photography (365 nm illumination) revealed that dark-fluorescent peppers only arise when cultivated under high-exposure conditions (0.7-fold decline at emission of 390 nm for high-exposure conditions). Microscopic and spectroscopic observations showed that blue autofluorescence was accompanied by an accumulation of UVB pigments (1.2-factor increase in the absorbance at 300 nm) and epidermal development (1.3-fold thicker cell wall). This study suggests that the autofluorescence of sweet pepper can possibly be used to understand the response of crop to solar radiation at a fruit level in horticulture.

DOI： 10.1007/s43630-022-00276-2

PubMed

researchmap

Authorship：Corresponding author  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOP Publishing  

Japanese tomato cultivar ‘Rinka 409’ is suitable for harvesting at a fully ripe stage since it remains firm at the stage, resulting in longer shelf life. However, it is difficult to estimate the quality change because its color does not change after the fully ripe stage. For ‘Momotaro,’ we previously proposed a fluorescence-based indicator of overripening; however, its suitability for another cultivar, ‘Rinka 409’, and its relationship with temperature and quality were unclear. Therefore, in this study, we investigated the appropriateness of this fluorescence-based index for the above purposes. In 2021, 45 tomato seedlings planted in 2020 were harvested at the fully ripe stage and used for experiments. Weight loss and firmness were evaluated to determine the quality of the tomatoes. The post-harvest temperatures were set as 10, 17, and 25 °C. The results showed that the rate of weight loss increased linearly, whereas the firmness decreased exponentially. For non-destructive estimation of these properties, the excitation-emission matrix (EEM) was measured in the range of 250–460 nm and 280–750 nm for the excitation and emission, respectively. ‘Rinka 409’ showed a strong fluorescence emission at 400 nm/620 nm of the excitation/emission, respectively, regardless of days and temperature. The fluorescence intensity, as well as the firmness, decreased exponentially. Thus, a linear relationship was observed between them. The firmness of ‘Rinka 409’ can be estimated using a simpler linear regression model using this method than previous researches.

DOI： 10.1088/1755-1315/924/1/012020

researchmap

Other Link： https://iopscience.iop.org/article/10.1088/1755-1315/924/1/012020/pdf

The study of bioactive compounds like food antioxidants is getting huge attention and curiosity by researchers and other relevant stakeholders (e.g., food and pharmaceutical industries) due to their health benefits. However, the currently available protocols to estimate the antioxidant activity of foods are time-consuming, destructive, require complex procedures for sample preparation, need technical persons, and not possible for real-time application, which are very important for large-scale or industrial applications. On the other hand, fluorescence spectroscopy and imaging techniques are relatively new, fast, mostly nondestructive, and possible to apply real-time to detect the antioxidants of foods. However, there is no review article on fluorescence techniques for estimating antioxidants in agricultural produces. Therefore, the present review comprehensively summarizes the overview of fluorescence phenomena, techniques (i.e., spectroscopy and computer vision), and their potential to monitor antioxidants in fruits and vegetables. Finally, opportunities and challenges of fluorescence techniques are described toward developing next-generation protocols for antioxidants measurement. Fluorescence techniques (both spectroscopy and imaging) are simpler and faster than available traditional methods of antioxidants measurement. Moreover, the fluorescence imaging technique has the potential to apply in real-time antioxidant identification in agricultural produce such as fruits and vegetables. Therefore, this technique might be used as a next-generation protocol for qualitative and quantitative antioxidants measurement after improvements like new material technologies for sensor (detector) and light sources for higher sensitivity and reduce the cost of implementing real-world applications.

DOI： 10.1080/10408398.2021.1992747

Scopus

researchmap

Publishing type：Research paper (scientific journal)  

J-GLOBAL

researchmap

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)=英国王立化学会  

We investigated the autofluorescence of tomato surface tissues during overripening. Microscopic images and fluorescence spectra of tissues were examined, revealing that the autofluorescence changes were related to the epidermis and the cuticle.

DOI： 10.1039/d0pp00125b

Web of Science

researchmap

Other Link： https://repository.kulib.kyoto-u.ac.jp/dspace/bitstream/2433/264237/1/d0pp00125b.pdf

Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

DOI： 10.1038/s41598-020-65955-5

researchmap

Other Link： http://www.nature.com/articles/s41598-020-65955-5

Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

Eggshells play a number of important roles in the avian and reptile kingdom: protection of internal contents and as a major source of minerals for developing embryos. However, when researching these respective roles, eggshell thickness measurement remains a bottleneck due to the lack of a non-destructive measurement techniques. As a result, many avian and reptile research protocols omit consideration of eggshell thickness bias on egg or embryo growth and development. Here, we validate a non-destructive method to estimate eggshell thickness based on terahertz (THz) reflectance spectroscopy using chicken white coloured eggs. Since terahertz waves are reflected from outer air-eggshell interface, as well as the inner eggshell-membrane boundary, the resulting interference signals depend on eggshell thickness. Thus, it is possible to estimate shell thickness from the oscillation distance in frequency-domain. A linear regression-based prediction model for non-destructive eggshell thickness measurement was developed, which had a coefficient of determination (R-2) of 0.93, RMSEP of 0.009, RPD of 3.45 and RER 13.67. This model can estimate eggshell thickness to a resolution of less than 10 mu m. This method has the potential to expand the protocols in the field of avian and reptile research, as well as be applied to industrial grading of eggs.

DOI： 10.1038/s41598-020-57774-5

Web of Science

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER  

The potential of UV-induced fluorescence imaging was investigated as a non-destructive tool to monitor postharvest quality degradation of tomatoes harvested at the red stage and stored at 25 degrees C. The fluorescence images (excitation at 365 nm) were found to be a better indicator of tomato quality degradation than color images after color saturation. Tomatoes were stored at 25 degrees C for 9 d. The changes in color and fluorescence of tomato were evaluated by two types of images: Color and fluorescence images. A conventional colorimeter was also used for as a reference. Changes in the RGB ratio for these two types of images were opposite. In the color images, the G ratio decreased rapidly for the initial 3 or 5 d and then stabilized afterwards. On the other hand, in the fluorescence images, the G ratio increased continuously up to 9 d. Given that temperature conditions during transportation and storage of tomatoes is not always ideal, the results from this research provide the foundation for developing a postharvest monitoring system of mature tomato quality degradation.

DOI： 10.1016/j.postharvbio.2019.111031

Web of Science

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE Computer Society  

Actin has two functional forms-monomeric actin and polymerized filaments. Actin filaments have been shown to contribute to the spatial arrangement of gene expression in the nucleus and to the establishment of pluripotent stem cells. However, the chemicals used to manipulate actin polymerization are cytotoxic and genotoxic, highlighting the importance of finding alternative methods. In this study, we showed that terahertz irradiation effectively stimulates polymerization of actin without denaturing its molecular structure.

DOI： 10.1109/IRMMW-THz.2018.8510110

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier B.V.  

DOI： 10.1016/j.eaef.2017.12.001

Scopus

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Optical Society (OSA)=米国光学会  

We measured the optical properties of drying wood with the moisture contents ranging from 10% to 200%. By using time-resolved near-infrared spectroscopy, the reduced scattering coefficient mu(s)' and absorption coefficient mu(a) were determined independent of each other, providing information on the chemical and structural changes, respectively, of wood on the nanometer scale. Scattering from dry pores dominated, which allowed us to determine the drying process of large pores during the period of constant drying rate, and the drying process of smaller pores during the period of decreasing drying rate. The surface layer and interior of the wood exhibit different moisture states, which affect the scattering properties of the wood. (C) 2016 Optical Society of America

DOI： 10.1364/OE.24.009561

Web of Science

researchmap

Authorship：Lead author,　Corresponding author   Language：Japanese  

researchmap

Event date： 2021.9

Venue：オンライン  

researchmap

Event date： 2021.7

Venue：オンライン  

researchmap

Event date： 2020.7

researchmap

Event date： 2019.11

Venue：京都府京都市  

researchmap

Event date： 2019.9

Venue：北海道札幌市  

researchmap

Event date： 2019.9

Language：Japanese  

researchmap

Event date： 2019.9

Venue：北海道札幌市  

researchmap

Event date： 2019.9

researchmap

Event date： 2019.6

Language：Japanese  

researchmap

Event date： 2018.10

Language：English  

© 2018 IEEE. Actin has two functional forms-monomeric actin and polymerized filaments. Actin filaments have been shown to contribute to the spatial arrangement of gene expression in the nucleus and to the establishment of pluripotent stem cells. However, the chemicals used to manipulate actin polymerization are cytotoxic and genotoxic, highlighting the importance of finding alternative methods. In this study, we showed that terahertz irradiation effectively stimulates polymerization of actin without denaturing its molecular structure.

researchmap

Event date： 2018.6

Language：Japanese  

researchmap

Event date： 2018.3

Language：Japanese   Presentation type：Poster presentation  

researchmap

Event date： 2018

researchmap

Event date： 2017

Language：Japanese  

researchmap

Event date： 2017

Language：Japanese  

researchmap

Event date： 2016.11

Language：Japanese  

researchmap

Event date： 2016.11

Language：Japanese  

researchmap

Event date： 2016.11

Language：Japanese  

researchmap

Event date： 2015.11

Language：Japanese  

researchmap

Event date： 2015.3

researchmap

Venue：オンライン  

researchmap

researchmap

Venue：岩手県盛岡市  

researchmap

Language：Japanese   Presentation type：Poster presentation  

researchmap

Venue：つくば市  

researchmap

Presentation type：Poster presentation  

Venue：東京都目黒区  

researchmap

Venue：高知県南国市  

researchmap

researchmap

Venue：オンライン  

researchmap

Country：Australia  

researchmap

researchmap

Venue：つくば市  

researchmap

Venue：つくば市  

researchmap