2023 Fiscal Year Research-status Report
Monitoring the absolute vegetable freshness index: light-NMR spectroscopy fusion approach
| Project/Area Number |
22K20606
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| Research Institution | National Agriculture and Food Research Organization |
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Principal Investigator |
李 心悦 国立研究開発法人農業・食品産業技術総合研究機構, 食品研究部門, 研究員 (40963947)
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| Project Period (FY) |
2022-08-31 – 2025-03-31
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| Keywords | komatsuna / freshness assessment / fluorescence fingerprint / informative fluorophores / selectivity ratio / PLSR analysis |
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| Outline of Annual Research Achievements |
This year, the feasibility of fluorescence spectroscopy for assessing the freshness of komatsuna (Japanese mustard spinach) was investigated. Different batches of komatsuna were acquired from the farm and treated under different storage conditions (including storage temperatures and durations) to achieve different freshness degrees, and then the corresponding fluorescence fingerprints of each fraction of komatsuna (including blade, stem, and petiole) were collected. Taking the freshness indicated by cumulative temperature as the objective and the collected fluorescence spectrum of komatsuna as the predictor, partial least squares regression (PLSR) analysis was respectively performed on each part of the komatsuna to establish a freshness prediction model with relatively high accuracy (the coefficients of determination of prediction are around 0.7-0.8). The models were built based on the informative fluorophores chosen by the stepwise selectivity ratio method. Based on the wavelengths of excitation and emission with higher selectivity ratios, it was known that the informative fluorophores (fluorescence components) important for the freshness prediction model construction could be attributed to chlorophylls, vitamins, or a specific component involved in stress responses, by which allows for the understanding of the model construction.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
We have previously developed methods using near-infrared (NIR) spectroscopy to assess the freshness of green vegetables, such as komatsuna and broccoli. This time, we estimate the freshness of komatsuna using a different non-destructive spectroscopy named fluorescence fingerprint (FF), which is a three-dimensional structure consisting of an excitation-emission matrix containing fluorophore intensities. We found that FF exhibited similar freshness prediction capabilities to NIR spectroscopy and provided complementary information (important fluorescence components) on komatsuna freshness compared to NIR spectroscopy. Furthermore, it was also found that the fluorescence components important for model construction are different in each fraction of komatsuna (including blade, stem, and petiole), which is different from the conclusions reported in studies of other vegetables such as spinach. This discovery is to be published and has not been reported so far. Therefore, the research is progressing smoothly as per the proposal.
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| Strategy for Future Research Activity |
To verify the applicability of fluorescence spectroscopy and investigate whether there are common informative fluorophores in different green vegetables for freshness assessment, it is planned to apply the same research approach to broccoli. It is expected that a reliable prediction model for vegetable freshness evaluation can be constructed based on the screened useful fluorescence signals, and the prediction model can be constructed with fewer wavelengths to improve the evaluation speed, which is beneficial to practical applications.
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| Causes of Carryover |
To make full use of this fund and achieve more precise research objectives, further experiments on broccoli freshness estimation using fluorescence spectroscopy are planned to validate and enrich the current research findings. Also, the results obtained are going to be published additionally (submitting one paper and exchange at academic conferences).
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Research Products
(5 results)
