Method of simultaneously analyzing amount of nutritional component in various foods having different physicochemical properties and compositions by near-infrared reflectance spectroscopy

1. A method of simultaneously analyzing amounts of a plurality of nutritional components in a plurality of foods or agricultural sources having different physicochemical properties and compositions by near-infrared reflectance spectroscopy, the method comprising:

(1) analyzing an amount of a nutritional component contained in a plurality of various species of foods and agricultural sources having different physicochemical properties and compositions by using analytical methods of analyzing components described in Korean Food Standard Codex;

(2) classifying the plurality of various species of foods or agricultural sources into a calibration sample set and a validation sample set;

(3) irradiating a near-infrared ray to the calibration sample set and the validation sample set to simultaneously obtain primitive near-infrared absorption spectra thereof;

(4) correcting scatter of the primitive near-infrared absorption spectrum of the calibration sample set obtained in the step (3);

(5) obtaining a derivative based on the primitive absorption spectrum of which scatter has been corrected, followed by subjecting the derivative to a math treatment represented by W-X-Y-Z where W is a differentiation degree, X is a gap (nm) of wavelength used to measure a spectrum, Y is a primary smoothing to smooth the connection of the spectrum during a math treatment with respect to the gap of wavelength, Z is a secondary smoothing to smooth the connection of the spectrum during the math treatment with respect to the gap of wavelength, and performing statistical analysis on the resultant derivative by comparing content values obtained based on the resultant derivative with content values obtained by using the analytical methods obtained in the step (1), thereby selecting primary calibration equations;

(6) validating the primary calibration equations selected in the step (5) by applying the primary calibration equations to the primitive near-infrared absorption spectra of the validation sample set obtained in the step (3) to obtain an optimal calibration equation; and

(7) quantitatively analyzing the nutritional component in the plurality of various foods or agricultural sources having different physicochemical properties and compositions by using the optimal calibration equation.

2. The method of claim 1 , wherein the plurality of various foods or agricultural sources having different physicochemical properties and compositions have at least one form selected from the group consisting of solid, liquid, and viscous semi-solid.

3. The method of claim 1 , wherein a ratio of the number of samples constituting the calibration sample set to the number of samples constituting the validation sample set in the step (2) is in a range of 2:1 to 3:1.

4. The method of claim 1 , wherein the near-infrared ray is irradiated by a horizontal direct contact food analyzer (DCFA) module, and the various foods or agricultural sources having different physicochemical properties and compositions are placed in a measurement vessel that is a cover-free, and transparent reflective vessel.

5. The method of claim 1 , wherein the nutritional component comprises at least one selected from the group consisting of a protein, a carbohydrate, a sugar, a fat, a fatty acid, an amino acid, an organic acid, a moisture, a vitamin, and a mineral.

6. The method of claim 1 , wherein the primitive near-infrared absorption spectra are obtained in a range of 400 nm to 2,500 nm.

7. The method of claim 1 , wherein a mode to measure the near-infrared absorption spectra is any one mode selected from the group consisting of a diffuse reflectance mode, a transmission-reflectance mode, and a transmission mode.

8. The method of claim 1 , wherein the near-infrared absorption spectrum is corrected by using at least one method selected from the group consisting of standard multiplicative scattering correction (standard MSC), inverse MSC, detrend correction, standard normal variate (SNV) correction, and weighted MSC.

9. The method of claim 1 , wherein the statistical analysis performed on the resultant derivative is a multivariate regression analysis.

10. The method of claim 9 , wherein the multivariate regression analysis is any one selected from the group consisting of multiple linear regression (MLR), principal component regression (PCR), partial least squares (PLS), and modified partial least squares (MPLS).

11. The method of claim 1 , wherein, when the nutritional component is carbohydrate, the scatter is corrected by weighted multiplicative scattering correction (weighed MSC), and the math treatment is selected from the group consisting of 1-4-5-1, 1-4-1-1, and 1-4-10-5.

12. The method of claim 1 , wherein, when the nutritional component is protein, the scatter is corrected by standard multiplicative scattering correction (standard MSC), and the math treatment is selected from the group consisting of 2-5-5-3, 2-5-10-1 and 2-6-1-1.

13. The method of claim 1 , wherein, when the nutritional component is fat, the scatter is corrected by standard normal variate (SNV) correction, and the math treatment is selected from the group consisting of 1-1-1-1, 1-1-3-1, and 1-3-10-5.