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Determination of fermented red-yeast rice products in the supplement suspected to be hazardous for humans

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Recent Studies at Faculty of Design

Determination of fermented red-yeast rice products in the supplement suspected to be hazardous for humans

Department of Environmental Design, Faculty of Design
Tomoko Imasaka, Lecturer

 My research group in the Faculty of Design at Kyushu University is developing a time-of-flight mass spectrometer using a femtosecond (10^-15 second) laser as an ionization source. As shown in Figure 1, this mass spectrometer is combined with a gas chromatograph for separation of the analytes such as organic compounds in PM2.5 [1], which is further applied to the evaluations of biofuels [2], exhaled breath [3], and psychotropic drugs [4].

 Last year, many people ingested supplements manufactured from fermented red-yeast rice and the supplements were suspected to induce serious health hazard. We recently measured the fermented red-yeast rice products in the sample lots that are suspected to be hazardous (see Figure 2) and non-hazardous using the analytical instrument developed in my laboratory.


 The observed results were published this year in an international academic journal [5]. Figure 3 shows total ion chromatograms measured for the two sample lots. The abscissa (horizontal axis) indicates the retention time for each component to elute from the chromatograph, and the ordinate (vertical axis) represents the signal intensity (concentration) of the analytes. It is interesting to note that several components (a) – (e) are enhanced significantly in the chromatogram measured for the contaminated sample, some of which are suspected to occur as a result of the metabolism of mycotoxins. The present analytical instrument would be useful for quality management of products such as a fermented rice-yeast rice supplement and would be helpful for pre-shipment inspections to avoid unexpected incidents that appeared this time.

Figure 1: Time-of-flight mass spectrometer using a femtosecond laser as an ionization source

Figure 2: Fermented red rice yeast supplement that is suspected to induce a health hazard.

Figure 3: Total ion chromatograms obtained by measuring the samples extracted from (A) a lot suspected to be hazardous and (B) a lot considered to be normal. Components (a)-(e) are strongly enhanced for (A).

 

References (underlined text by Tomoko Imasaka, * indicates corresponding author, all peer-reviewed, click on the DOI to go to the original paper)

[1] L. Wen, K. Yoshinaga, T. Imasaka, T. Imasaka*, Trace Analysis of Nitrated Polycyclic Aromatic Hydrocarbons Based on Two-Color Femtosecond Laser Ionization Mass Spectrometry, Talanta, 2023 265, 124807.　DOI: 10.1016/j.talanta.2023.124807

[2] T. Imasaka*, K. Yoshinaga, T. Imasaka, Machine Learning for Characterizing Biofuels Based on Femtosecond Laser Ionization Mass Spectrometry, Analytical Chemistry, 2024 96, 10193-10199.　 DOI: 10.1021/acs.analchem.4c00478

[3] K. Yoshinaga, T. Imasaka, T. Imasaka*, Femtosecond Laser Ionization Mass Spectrometry for Online Analysis of Human Exhaled Breath, Analytical Chemistry, 2024 96, 11542-11548.　　DOI: 10.1021/acs.analchem.4c02214

[4] C.H. Lin, K. Yoshinaga, T. Imasaka, T. Imasaka*, Determination of Benzodiazepines via Gas Chromatography Combined with Femtosecond Laser Ionization Mass Spectrometry, Microchemical Journal, 2025 215, 114356.  DOI: 10.1016/j.microc.2025.114356

[5] T. Imasaka*, K. Yoshinaga, C.-H. Lin, and T. Imasaka, Analysis of Fermented Red-Yeast Rice Products Using Femtosecond Laser Ionization Mass Spectrometry, Journal of the American Society for Mass Spectrometry 2025 36, 1439-1442.　　DOI: 10.1021/jasms.5c00029

■Contact
Department of Environmental Design, Faculty of Design
Tomoko Imasaka, Lecturer