Near-infrared Spectroscopy (NIRS)
Near-infrared spectroscopy (NIRS)
Japanese: 近赤外分光法（きんせきがいぶんこうほう）
Non-destructive analysis using light. Simultaneously estimates moisture, protein, and sugar content.
NIRS irradiates samples with near-infrared light (800-2500nm wavelength) and estimates components from absorption spectrum patterns. Moisture, protein, fat, and sugar can be measured simultaneously in seconds.
Calibration is required beforehand, but once built, rapid non-destructive analysis is possible. Miso factories use it for raw material inspection and product quality checks. Knowing contents just by shining light — an excellent example of science contributing to fermentation quality control.
Calibration curve construction requires statistical correlation between chemical reference values and NIR spectra. Chemometric methods like principal component analysis (PCA) and PLS regression are employed. Temperature fluctuations and sample heterogeneity affect accuracy, so periodic calibration updates are recommended.