Exploring how Japanese researchers are transforming light-based technology into tools that improve lives, protect heritage, and advance science.
Imagine a technology that could peer inside a pharmaceutical pill to guarantee its potency, monitor blood glucose levels without a single drop of blood, or determine the authenticity of ancient artifacts without touching them. This isn't science fiction—it's the remarkable reality of near-infrared (NIR) spectroscopy, an analytical technique that's revolutionizing fields from medicine to manufacturing. At the forefront of this quiet revolution is Japan, a country that has emerged as a global leader in advancing NIR technology through cutting-edge research and development.
Japan has become a significant player in the IR spectroscopy industry, with particular leadership in research and development for pharmaceutical analysis 1 .
Japanese companies like Shimadzu Corporation and Hitachi High-Tech Corporation stand alongside international giants as key players in the global spectroscopy market 5 .
Near-infrared spectroscopy is an analytical technique that measures how molecules interact with near-infrared light—invisible electromagnetic radiation with wavelengths just longer than what the human eye can perceive. When NIR light shines on a sample, whether it's a pharmaceutical tablet, a food product, or human tissue, specific chemical bonds within the molecules vibrate and absorb characteristic wavelengths of this light 1 . The resulting pattern of absorption creates a unique molecular "fingerprint" that reveals critical information about the sample's composition and properties 1 .
The true power of NIR spectroscopy lies in its ability to perform non-destructive analysis, meaning samples remain completely unchanged and unharmed during examination 6 . This distinguishes it from many traditional analytical methods that require extensive sample preparation or alter the material being studied.
Comparison of analysis speed across different analytical techniques
Japan has established particularly strong leadership in applying NIR spectroscopy to pharmaceutical research and development. The country is recognized for pioneering work in drug development and quality assurance initiatives, leveraging NIR technology to ensure medication safety and efficacy 1 .
One of the most promising areas of Japanese NIR research involves non-invasive medical diagnostics. Researchers across Japan are exploring innovative ways to use NIR technology for disease detection and health monitoring without invasive procedures .
Japanese researchers have pioneered the application of NIR spectroscopy to cultural heritage preservation and wood science. In a compelling 2015 study, scientists used NIR spectroscopy to distinguish between anatomically similar Japanese pine species 8 .
A remarkable example comes from a research team at Kagawa University, which has proposed a new principle called the "emission integral effect" for non-invasive blood glucose monitoring using mid-infrared spectroscopy 4 . The team discovered that dilute components like glucose may be more identifiable than concentrated ones in emission measurements, potentially explaining why mid-infrared passive spectroscopic imaging can successfully correlate with blood glucose levels despite glucose's relatively low concentration in blood 4 .
A landmark study exemplifying the innovative application of NIR spectroscopy in pharmaceutical processing comes from Japanese-affiliated researchers investigating the steaming process of Gastrodiae rhizoma (G. rhizoma), a traditional Chinese medicine known as "Tianma" 3 . Steaming is a crucial processing step that affects the active ingredients and pharmacological efficacy of the herbal product.
The research team designed an experiment using an Antaris II FT-NIR analyzer to dynamically monitor the steaming process in real-time. They collected spectra from 10 different batches of G. rhizoma during steaming, gathering approximately 200 samples total. The NIR spectra were obtained in diffuse reflection mode across the wavelength range of 4,000-12,000 cm⁻¹ with a resolution of 8 cm⁻¹ 3 .
To translate spectral data into meaningful chemical information, researchers developed multivariate calibration models using different mathematical approaches:
| Compound Analyzed | Model Type | Purpose |
|---|---|---|
| Gastrodin | Partial Least Squares (PLS) | Quantify active ingredient |
| p-hydroxybenzyl alcohol | PLS | Quantify active ingredient |
| Parishin B | PLS | Quantify active ingredient |
| Parishin A | PLS | Quantify active ingredient |
| Moisture Content | Principal Component Regression (PCR) | Measure water loss during processing |
Reference measurements for model development were obtained using high-performance liquid chromatography (HPLC) for the active compounds and the weight loss method for moisture content, according to the Chinese Pharmacopoeia 3 .
The NIR spectroscopy method demonstrated impressive accuracy in monitoring the herbal medicine processing:
| Compound | RMSEP | Rₚ² | Accuracy |
|---|---|---|---|
| Gastrodin | 0.0181 | 0.9591 | Excellent |
| p-hydroxybenzyl alcohol | 0.0143 | 0.9307 | Excellent |
| Parishin B | 0.0132 | 0.9309 | Excellent |
| Parishin A | 0.0244 | 0.9277 | Excellent |
| Moisture | 2.15 | 0.9201 | Excellent |
This successful application of NIR spectroscopy as a Process Analytical Technology tool represents a significant advancement over traditional subjective color judgment and time-consuming HPLC methods 3 . The study highlights how NIR spectroscopy can enhance quality control in traditional medicine processing by providing real-time monitoring of multiple chemical components simultaneously.
The advancement of NIR spectroscopy research in Japan and globally relies on a sophisticated collection of instruments, software, and analytical tools. This "scientific toolkit" enables researchers to extract meaningful information from the complex NIR spectra and develop practical applications across diverse fields.
| Tool Category | Specific Examples | Function and Application |
|---|---|---|
| Instrumentation | FT-NIR Analyzers (Antaris II) 3 , Portable NIR Spectrometers 6 | Laboratory and field-based spectral acquisition |
| Software & Algorithms | Partial Least Squares (PLS) 3 , Principal Component Analysis (PCA) 8 , Stepwise Multiple Linear Regression (SMLR) 3 | Extracting meaningful information from complex spectral data |
| Reference Methods | HPLC 3 , Reference Chemical Standards 3 | Model calibration and validation |
| Specialized Accessories | Integrating Sphere Diffuse Reflection Accessories 3 , Fiber Optic Probes | Adapting instrumentation to different sample types and measurement scenarios |
As Japan continues to innovate in NIR spectroscopy, several emerging trends suggest exciting directions for future research and application:
Two of the most significant trends in Japanese NIR research are the integration of artificial intelligence and the ongoing miniaturization of instruments. Experts are increasingly implementing AI and machine learning to improve data analysis and interpretation of complex NIR spectra 1 .
Simultaneously, the push for portable and miniaturized spectrometers continues to advance 1 . Japanese researchers and companies are developing increasingly compact NIR devices that maintain high performance despite reduced size.
Laboratory instruments with AI-assisted data analysis
Portable devices with real-time AI interpretation
Wearable NIR sensors with continuous monitoring capabilities
The Society for functional Near Infrared Spectroscopy (SfNIRS) has a significant Asian presence, with the 2026 biennial conference scheduled for Macau and active Japanese participation in this growing field 7 .
Japan's extensive efforts to improve environmental monitoring and food safety standards have accelerated demand for NIR spectroscopy instrumentation 1 .
Continued expansion in these traditional strengths includes new methods for disease detection, counterfeit drug identification, and non-destructive analysis of biological samples .
Japan's strong position in both instrumentation manufacturing and research applications, combined with its culture of precision and quality, suggests the country will remain at the forefront of NIR spectroscopy advancements for the foreseeable future. As research continues to overcome current challenges like calibration complexity and matrix effects 6 , NIR spectroscopy will likely find even broader adoption across scientific, industrial, and medical fields.
From ensuring the quality of life-saving medications to preserving cultural treasures and pioneering non-invasive medical diagnostics, Japan's advancements in near-infrared spectroscopy demonstrate how fundamental scientific principles, when applied with creativity and precision, can transform diverse aspects of human life.
The story of NIR spectroscopy in Japan is ultimately about making the invisible visible—revealing hidden chemical information that helps us make better medicines, protect our heritage, understand our bodies, and improve our world. As this technology continues to evolve, guided by Japanese precision and innovation, we can expect even more remarkable applications of this extraordinary ability to see what the eye cannot.