Chiaki Ishikawa

Ms. Chiaki Ishikawa

Institute of Food Research, National Agriculture and Food Research Organization, Tsukuba, Japan
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Research Focus & Metrics

Academic Career Length

36Years (1991-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 September 2022 in Metabolites
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Journal Article
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YDYasuhiro Date
Yasuhiro Date
CIChiaki Ishikawa
Chiaki Ishikawa
MUMakoto Umeda
Makoto Umeda
YTYusuke Tarumoto
Yusuke Tarumoto
MOMegumi Okubo
Megumi Okubo
HOHiroshi Ono
Hiroshi Ono
Sugarcane is essential for global sugar production and its compressed juice is a key raw material for industrial products. Sugarcane juice includes various metabolites with abundances and compositional balances influencing product qualities and functionalities. Therefore, understanding the characteristic features of the sugarcane metabolome is important. However, sugarcane compositional variability and stability, even in pretreatment processes for nuclear magnetic resonance (NMR)-based metabolomic studies, remains elusive. The objective of this study is to evaluate sugarcane juice metabolomic variability affected by centrifugation, filtration, and thermal pretreatments, as well as the time-course changes for determining optimal conditions for NMR-based metabolomic approach. The pretreatment processes left the metabolomic compositions unchanged, indicating that these pretreatments are compatible with one another and the studied metabolomes are comparable. The thermal processing provided stability to the metabolome for more than 32 h at room temperature. Based on the determined analytical conditions, we conducted an NMR-based metabolomic study to discriminate the differences in the harvest period and allowed for successfully identifying the characteristic metabolome. Our findings denote that NMR-based sugarcane metabolomics enable us to provide an opportunity to collect a massive amount of data upon collaboration between multiple researchers, resulting in the rapid construction of useful databases for both research purposes and industrial use.

15 August 1991 in Journal of Applied Physics
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Journal Article
Closed access
CIChiaki Ishikawa
Chiaki Ishikawa
SSShinobu Sasaki
Shinobu Sasaki
EMEijin Moriwaki
Eijin Moriwaki
YHYoshihiro Hamakawa
Yoshihiro Hamakawa
KSKazuo Shiiki
Kazuo Shiiki
KSKiminari Shinagawa
Kiminari Shinagawa
The dynamic behavior of a 180° wall was observed in a Co-based amorphous alloy film using a Kerr microscope. As a function of an anisotropy direction the amplitude of the 180° wall movement was measured with the drive field applied transverse to the 180° wall of the closure domain structure. The anisotropy direction was varied by magnetic heat treatment. It was found that the 180° wall moved independently of the anisotropy direction, that is, the 180° wall movement is related only to the applied high-frequency field. To clarify the cause of the 180° wall movement, the magnetic energy of the domain structure and the eddy current loss caused by the high-frequency field were calculated. However, the movement could not be understood completely in terms of energy balance since the magnetostatic energy increases faster than the decrease of the eddy current loss, when the 180° wall moves.

17 July 2024 in Nutrients
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RARisa Araki
Risa Araki
CIChiaki Ishikawa
Chiaki Ishikawa
TKTomomi Kawasaki
Tomomi Kawasaki
TKToshiro Kobori
Toshiro Kobori
TSToshihiko Shoji
Toshihiko Shoji
YTYoshiharu Takayama
Yoshiharu Takayama
β-(1,3/1,4)-glucan is a major component of cereal grains, such as oats and barley. In this study, we investigated the effects of cooked waxy barley, which contains β-(1,3/1,4)-glucan, on upper respiratory tract physical symptoms and mood status by performing a randomized, parallel-group, comparative trial. The primary outcome was assessed using the Wisconsin Upper Respiratory Symptom Survey-21 and Profile of Mood States second edition. Twenty-seven healthy Japanese adult participants were supplemented with 100 g of cooked waxy barley (containing 1.8 g of β-glucan) or 100 g of cooked white rice daily for 8 weeks. Participants receiving cooked waxy barley reported a reduction in cumulative days of sneezing (p < 0.05) and feeling tired (p < 0.0001) compared with the control group. After the intervention period, there were significantly less severe nasal symptoms, such as runny nose, plugged nose, and sneezing (p < 0.05), and a significantly greater reduction of the Tension-Anguish score (p < 0.05) in the barley group than in the control group. This study suggests that supplementation of cooked waxy barley containing β-(1,3/1,4)-glucan prevents or alleviates nasal upper respiratory tract symptoms and improves mood status. The findings of this study should be confirmed by double-blind trials with a larger number of participants.

20 August 2025 in Metabolites
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Journal Article
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YDYasuhiro Date
Yasuhiro Date
CIChiaki Ishikawa
Chiaki Ishikawa
HOHiroshi Ono
Hiroshi Ono
Background: Metabolomics is a powerful tool used for the evaluation of sugarcane components which are key factors influencing its response to biotic and abiotic stresses. However, little is known about the compositional variability and diversity of the sugarcane juice metabolome under practical field conditions in temperate climates. Methods: In this study, we characterized metabolomic differences and variability in sugarcane juice components during the maturation stage of nine cultivars grown in a temperate climate in Japan using a nuclear magnetic resonance-based metabolomics approach, aiming to provide insights into genotype-dependent adaptability to environmental and climate changes. Results: Principal component analysis revealed distinct metabolic profiles based on cultivar and maturation level. Notably, sucrose levels increased from September to December accompanied by decreased glucose and fructose levels across all cultivars. Early-maturing cultivars had high sucrose content even with shorter growing periods, suggesting particular advantages for sugar production in temperate climates. Additionally, 4-aminobutyric acid accumulated in all cultivars as maturation progressed. On the other hand, trans-aconitic acid, choline, and branched-chain amino acids showed cultivar-dependent trends. In one example, choline concentrations increased significantly in specific cultivars during maturation. Conclusions: These findings support a deeper understanding of metabolic adaptation and may aid in identifying cultivars better suited to environmental fluctuations.