JP3495185B2 - Method and apparatus for measuring rice taste value - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring the taste value of rice, which estimates a grade representing the taste of rice using near infrared analysis.

[0002]

2. Description of the Related Art Regarding the taste value of rice, the rice cooked by a predetermined method is sampled by a plurality of panelists, and the results are evaluated as close to the standard evaluation as possible by using statistical means. ing. Evaluation items are generally “appearance”
"Taste", "hardness", "stickiness", "aroma", and "general taste" are conducted. In addition, a taste value measuring device that directly measures the taste value by irradiating near infrared light with rice grains as a sample using the near infrared analysis method is also commercially available. Further, as another example using the near-infrared analysis method, a method of measuring components contained in rice grains, that is, protein, amylose, water content, fatty acid degree, etc. by near-infrared analysis, and measuring the taste value from the degree of their composition is also performed. ing. Japanese Patent Publication No. 6-12331 discloses a method of detecting the specularly reflected light of cooked rice as polarized light and detecting the taste of rice from the surface condition of the rice.

[0003]

The sensory test by tasting panelists usually requires 12 to 24 panelists,
Only a few points can be measured in one day to sample the rice,
There is also a problem with the reproducibility of measured values. In addition, the method of directly measuring the taste value by irradiating the sample rice with near infrared rays is to analyze the spectrum of the reflected light or the transmitted light of the near infrared irradiation for the whole grain rice of the sample rice, but it depends on the difference in taste value. Changes in absorbance in the near-infrared region are very small, and variations in basic components such as water, starch, and proteins other than taste substances, which are said to represent differences in the eating quality of rice, and physical changes such as sample particle size changes There is a problem that it is difficult to measure the taste with high accuracy due to interference of both due to scattering of the spectrum due to factors. In addition, the method of estimating the taste from the compositional degree of the components in the rice grain by the near-infrared analysis method, the range of the contained components such as protein and amylose of Japonica rice used for ordinary rice cooking is narrow, and the evaluation obtained by sensory evaluation. The correlation with the value is not very high. Further, in the technique of Japanese Patent Publication No. 6-12331, it is necessary to cook rice and measure it, which is troublesome and cannot meet the demand of the nondestructive inspection required by the user.

The present invention has been made in view of the above-mentioned problems, and provides a method and apparatus for measuring the taste value of rice which can be accurately measured by using the near infrared analysis method without cooking the rice. The purpose is to

[0005]

[Means for Solving the Problems]

[0006]

[0007]

[0008]

[0009]

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

In order to achieve the above-mentioned object, the present invention prepares a plurality of samples of milled rice of which grades showing the taste based on a sensory test are known, and prepares samples of the milled rice of each sample for each grade. The surface layer was ground to prepare the first sample and the remaining second sample of the surface layer portion, and the absorbance of each wavelength of the first spectrum obtained by irradiating the first sample with near-infrared light was determined to obtain the same grade. First
For each sample, a standard spectrum composed of the average value of the absorbance of the same wavelength of each first sample was obtained for each grade, and the first spectrum of each first sample and the standard spectrum of each grade were obtained for each grade. In comparison, the first sample is most similar to the standard spectrum of the grade to which it belongs, the first group that is most similar to the standard spectrum below the grade to which it belongs, and above the grade to which it belongs. Into a third group that is most similar to the standard spectrum of
For each grade, the second sample corresponding to each first sample is irradiated with near-infrared light to obtain a second spectrum, and the spectrum of the second sample corresponding to the first sample of the first group
The standard spectrum is used, the spectrum of the second sample corresponding to the first sample of the second group is used as the second standard spectrum, and the spectrum of the second sample corresponding to the first sample of the third group is used as the third standard spectrum. The surface layer of polished rice of the sample is ground to prepare a first sample of the surface layer and the remaining second sample, and the first sample is irradiated with near-infrared light to obtain a first spectrum. The most similar standard spectrum is obtained by comparing with the standard spectrum of the grade, and the grade of this standard spectrum is used as the initial grade, and then the second sample is irradiated with near infrared light to obtain the second spectrum, and the initial grade is obtained. The first standard spectrum, the second standard spectrum, and the third standard spectrum are compared, and when the first standard spectrum is the most similar, the initial grade is used as the grade of the sample to be measured, and the second standard spectrum and the most similar type. When is a grade one step below the initial grade, when most similar to the third standard spectrum to provide a rice palatability measuring method characterized in that a grade 1 level upper than the initial grade.

The present invention is a method of correcting the grade obtained from the surface layer of polished rice based on the spectrum of the remaining portion excluding the surface layer. It is usually related to the taste of polished rice
It is the surface part of rice after pearling, but on the other hand, since the rice is chewed and eaten, the central part of the remaining endosperm excluding the surface part is also related to the taste. For this reason, the taste is evaluated also in this central part, and the evaluation obtained on the surface is confirmed and its correction is performed.

Several tens of samples of polished rice of which grades showing taste are known by a sensory test are prepared for each grade, and a first sample consisting of a surface layer portion obtained by grinding the surface layer and a second sample consisting of the remaining central portion thereof are prepared. Correspond the samples. All the first samples contained in each grade are irradiated with near-infrared light, the average value of the absorbance of each wavelength of the obtained first spectrum, for example, the wavelength of every 2 nm is obtained, and it is composed of this average value. When the spectrum is a standard spectrum, a standard spectrum is obtained for each grade. Next, for each grade, the spectrum of each first sample is compared with the standard spectrum of each grade, and the set of the first samples having the spectrum most similar to the standard spectrum of the grade to which it belongs is set as the first group. Of course most of the first samples belong to the first group. However, the first sample that most closely resembles the standard spectrum of the first sample of the grade below its own grade also appears, and the set of this first sample is set as the second group, and the standard of the grade above the grade to which it belongs also The first sample set that most resembles the spectrum is
Make a group. It is the invention according to the present invention to correctly estimate the grade of the first sample belonging to the second and third groups.

For the second sample corresponding to the first sample of the first to third groups thus obtained, the second spectrum by near infrared light is obtained, and the first sample belonging to the first group is obtained.
The second spectrum of the second sample corresponding to the sample is the first standard spectrum, the second spectrum of the second sample corresponding to the second group is the second standard spectrum, and the second spectrum of the second sample corresponding to the third group. The 2 spectra are the third standard spectra. Since there are a plurality of second spectra of the second sample belonging to the same group, a spectrum composed of the average value of the absorbance of each wavelength of the plurality of second spectra may be used as each standard spectrum.

Next, a first sample and a second sample of the sample to be measured are prepared and irradiated with near infrared light to obtain a first spectrum and a second spectrum. The first spectrum is compared with the standard spectrum of each grade, and the grade of the most similar standard spectrum is used as the initial grade. This initial grade is the grade obtained by the invention of claim 1. The first to third standard spectra of the initial grade and the second spectrum are compared with each other. When the spectrum is most similar to the first standard spectrum, the initial grade is used as the grade of the sample to be measured.
When it is most similar to the 2nd standard spectrum, the grade of the measured sample is one step below the initial grade, and when it is most similar to the 3rd standard spectrum, the grade of the measured sample is one step above the initial grade. And The taste of rice is made up of a large proportion of the surface layer of polished rice, so it is often the initial grade,
Even when it goes out of this range, the upper and lower grades are about 1 grade, so the above grades are set. By thus performing the two-stage determination, even if the initial grade by the first sample is incorrect, the second grade can be corrected to obtain the correct grade.

When a specific wavelength is determined for at least one of the first standard spectrum, the second standard spectrum, and the third standard spectrum, and when the specific wavelength is compared with the second spectrum of the sample to be measured, the absorbance at the specific wavelength is compared. Preferably.

The first to third standard spectra often include one or more specific wavelengths having a characteristic in each spectrum, and the grade can be determined by comparing the absorbances of these wavelengths. Many. Since it is only necessary to compare the absorbances with respect to such specific wavelengths, the calculation time for determining the grade by comparison is greatly shortened.

For example, when the initial grade is the lowest grade and the grade is one step lower than the initial grade, this is the lowest grade, and the highest grade is the grade one step higher than the initial grade. When this is the highest grade.

When the initial grade is the lowest grade, there is no grade lower than it. In addition, since there is no higher grade than the highest grade, when the grade does not exist, the grade is not changed and the grade is the same as the initial grade.

As the spectrum or the absorbance, a second derivative of the intensity of the reflected light or the transmitted light with respect to the wavelength can be used.

The absorbance or the spectrum may be the absorbance itself, but normally, by using a value obtained by normalizing and secondarily differentiating with respect to the wavelength, it is possible to cancel a measurement error due to a drift or a change in illumination intensity.

[0027]

[0028]

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the calibration of the first to third embodiments. Sample 1 is a sample powder of the surface layer portion obtained by grinding the surface layer of milled rice in an amount of 1 to 6% by weight with a grinding type rice polishing machine. Polished rice is obtained by removing the rice bran layer, which corresponds to approximately 10% by weight of the surface layer of rice grain, with a rice polishing machine, when 100% by weight of brown rice is used. The near-infrared light measuring device 2 irradiates the sample 1 with near-infrared light and measures the spectrum of its reflected light or transmitted light. The spectrum calculation unit 3 calculates the absorbance of the wavelength measured every 2 nm for the spectrum measured by the near infrared light measuring device 2. The grade data storage unit 4 stores the standard spectra for each grade based on the taste obtained by the sensory test, for example, 2
The data of the absorbance of the wavelength sampled for each nm are stored. The grade calculation unit 5 calculates the absorbance of each wavelength of the spectrum of the sample to be measured calculated by the spectrum calculation unit 3 and the absorbance of each wavelength of the standard spectrum of each grade stored in the grade data storage unit 4. The similarity is calculated, the grade with the highest similarity is detected, and this grade is used as the grade of the sample to be measured. The display unit 6 displays the grade calculation result.

FIG. 2 is a diagram showing the structure of a near infrared light measuring device. Near-infrared light is emitted from the light source 21, and the emitted light that has passed through the slit is reflected by the mirror 22 and enters the diffraction grating 23. By vibrating the diffraction grating 23, the near-infrared region 70
The wavelength range of 0 to 2500 nm is scanned every 2 nm. The reflection measuring unit 24 measures the reflected light reflected from the sample 1 by the light thus scanned. The transmission measuring unit 25 measures the transmitted light transmitted through the sample 1.

The taste measurement based on the above-mentioned device will be described. It has become clear that so-called good-tasting rice contains a large amount of this taste substance, and generally, non-tasting-tasting rice contains a small amount. Taste substances include reticulated starch, oligosaccharides, amino acids, magnesium phosphate, and the like. The surface layer of polished rice contains a large amount of this taste substance in an amount of 0 to 6% by weight. Further, the deterioration of the taste with time due to the so-called old rice is a phenomenon initiated by the alteration and decomposition of these taste substances, and therefore progresses as rapidly and remarkably as the surface layer. Therefore, the surface layer of 1 to 6% by weight as the sample powder is ground. Desirably, 4 to 5% by weight is good. It is possible to measure even if it is less than 1% by weight, but the accuracy is lowered. From 6% to 10% by weight or more of the surface layer of milled rice approaches the endosperm center, the composition of this part mainly contains a large amount of starch, and the taste substances and proteins present in the surface layer decrease. ing. For this reason, the difference in the composition of rice, which separates good-tasting rice from non-tasting rice, exists only in a small amount in the portion close to the endosperm center. However, the texture also affects the texture when chewing, so the texture due to this endosperm portion is also considered. The content of the taste substance contained in the above 0 to 6% by weight is about 0.1 to 0.2% by weight of the polished rice, which is a very small amount. Here, the polished rice is a rice grain obtained by removing a bran layer corresponding to about 10% by weight of the surface layer of rice grain with a rice polishing machine, when 100% by weight of brown rice is used, and is generally in a state of being commercially available.

The sample powder 1 thus obtained is irradiated with near-infrared light by the near-infrared light measuring device 2 shown in FIG. A wavelength range of 700 to 2500 nm is scanned every 2 nm to obtain a spectrum of reflected light or transmitted light. The spectrum obtained here is subjected to spectrum calculation (differentiation) processing in order to remove the influence of noise and the like and improve the measurement accuracy. The number of wavelength data points per sample of sample powder 1 is 2500-700 because the wavelength range is 700 to 2500 nm.
= 1800, because data is taken every 2 nm, 1800 ÷
2 = 900 absorbance data.

The grade representing the taste of rice will be described. In the sensory taste test, the overall taste, taste, stickiness, etc. are given as evaluation values for sample rice prepared by polishing polished rice. When determining the grade of the taste value, these may be comprehensively graded, or only the comprehensive taste value may be graded. -1
(Poor taste), 0 (intermediate taste), +1 (quantity taste), or 1
(Somewhat inferior), 2 (normal), 3 (somewhat good), 4 (good),
5 (especially good), and the grading method is not particularly limited.

The first embodiment for determining the grade of the sample to be measured will be described below. When determining the grade of the sample to be measured using the near-infrared analysis method, a standard spectrum as a reference for determination is set. 10 to 20 samples of polished rice of the same type or the same lot as the polished rice used in the sensory test are prepared for each grade determined based on the taste obtained by the sensory test. Since it is necessary for all grades, sample rice that is several times this grade is required. It is not limited to genetic varieties such as Koshihikari and Sasanishiki that are categorized as “types” of polished rice here, but different types of sample rice that differ according to production area, storage method, storage period, etc. deal with.

With respect to all the sample rices of each grade, the sample powder obtained by grinding the surface layer of polished rice in an amount of 4 to 5% by weight was scanned in the wavelength range of 700 to 2500 nm in the near infrared region every 2 nm to obtain 900 absorbance data. obtain. These absorbance data are subjected to logarithmic processing and differential processing before use. If the reflected light intensity is R, the transmitted light intensity is T, and the wavelength is λ,
d ² (logR) / dλ ² or d ² (logT) / d
λ ² is calculated, and this second derivative is hereinafter referred to as absorbance data. As described above, the absorbance or the spectrum consisting of the absorbance at each wavelength may use the reflected light intensity R or the transmitted light intensity T, but normally, the first derivative or the second derivative of the logarithmic value of these values is used to obtain a normal value. By using it in a digitized form, the drift and changes in illumination intensity are canceled out and the measurement error is reduced.

Regarding the spectrum of each sample powder thus obtained for each grade (collection of absorbance at each wavelength),
The average value of the absorbance of each sample powder at each wavelength is obtained, and the spectrum composed of this average value is called the standard spectrum.
A standard spectrum is created for each grade.

Next, with respect to the polished rice as a sample to be measured, the surface layer powder having the surface layer ground by 4 to 5% by weight is sampled, and the spectrum is measured by irradiating with near infrared light. The measurement method and measurement values are the same as those for sample rice of known grade. The spectrum of the sample to be measured thus obtained is compared with the standard spectrum of each class obtained previously, and the class of the most similar standard spectrum is set as the class of the sample to be measured.

There are several known methods for investigating the similarity between two spectra, which will be briefly described below. The first method is the method disclosed in Japanese Patent Publication No. 6-40069 of the same applicant, where n is the number of wavelengths in the spectrum, the absorbance at each wavelength is represented by an n-dimensional vector. Letting θ be the intersection angle between the n-dimensional vector of the standard spectrum and the n-dimensional vector of the sample to be measured, cos θ represents the degree of similarity. If the two spectra match, the two vectors match and the crossing angle θ =
0, cos θ = 1, and θ becomes closer to 0 and cos θ approaches 1 as the similarity between the two spectra becomes larger. cos θ
Is expressed by the following equation (1).

[0039]

[Equation 1]

Here, xi is the absorbance at the wavelength i of the standard spectrum, and yi is the absorbance at the wavelength i of the spectrum of the sample to be measured.

The second method for checking the similarity between two spectra is to use a product moment correlation coefficient. The product-moment correlation coefficient r is expressed by equation (2). If both spectra are the same, the absorbance at each wavelength is the same, r = 1, and approaches 1 when the degree of similarity increases. xi: absorbance of standard spectrum, x is the average value of xi, y
i is the absorbance of the sample to be measured, y is the average value of yi, and n is the number of wavelengths.

[0042]

[Equation 2]

The third method for examining the similarity between two spectra is a method using variance. The square of the difference in absorbance at the same wavelength between the standard spectrum and the spectrum of the sample to be measured is calculated, and the value obtained by adding the squares is defined as the variance. This dispersion becomes 0 if both spectra match, and approaches 0 as the degree of similarity increases. The dispersion S is expressed by the following equation (3). xi indicates the absorbance at the wavelength i of the standard spectrum,
yi represents the absorbance at the wavelength i of the sample to be measured. Since the number n of wavelengths is the same in both spectra, it is not necessary to divide the sum of squares of the difference in absorbance by the degree of freedom obtained by subtracting 1 from n.

[0044]

[Equation 3]

Next, a second embodiment will be described. Similar to the first embodiment, 10 to 20 sample powders of the surface layer of polished rice of which grades are known by sensory test are prepared for each grade, and all sample powders of each grade are irradiated with near infrared light. And obtain the spectrum. kj is a coefficient, xi is the absorbance at the wavelength i, n is the number of wavelengths, and c is the grade in the equation (4). Regression analysis using the least squares method is performed with xi and c as numerical data, and an n-dimensional simultaneous equation is used. Solve a normal equation to obtain k0, k1, ... kn.

C = k0 + k1x1 + k2x2 + ... + knxn (4) Next, the surface layer powder obtained by grinding the surface layer of the polished rice of the sample to be measured is irradiated with near infrared rays to measure the spectrum, and each wavelength i
The absorbance yi at is calculated, and this yi is calculated as xi in equation (4).
Substituting into Since this c usually has a value including the decimal point, the grade represented by the integer value closest to this c is the grade of the sample to be measured.

Next, a third embodiment will be described. In the first and second embodiments, the surface layer powder obtained by grinding the surface layer of milled rice (this is referred to as the first sample) was used as the sample, but in the present embodiment, the upper layer powder is removed and the remaining The part (referred to as a second sample) is also used as a sample, the initial grade is first calculated in the first sample, and the initial grade is corrected using the second sample. Since the taste of rice is chewed and eaten, it is also affected by the degree of chewing, and the endosperm of the central part of polished rice is also involved.
The initial grade determined on the surface is corrected with the second sample in the middle.

10 to 20 samples of polished rice of which grades showing taste based on a sensory test are known are prepared for each grade, and the surface layer of this sample is ground to make the first sample of the surface layer portion and the remaining second sample.
A sample is prepared and each is irradiated with near infrared light to obtain a first spectrum and a second spectrum. The spectrum wavelength and wave number are the same as in the first embodiment. The first sample and the second sample collected from the same polished rice are associated with each other. The second sample may be in the form of granules, but it is better to make it powdery like the first sample.

A standard spectrum is obtained by averaging the absorbances at the same wavelength for all the first samples of the same grade. Therefore, the standard spectra are obtained for the number of grades. Next, the similarity between the first spectra of all the first samples of the same grade and the standard spectrum of the grade to which the user belongs belongs to, and the set of the first samples most similar to the grade to which the user belongs belongs to the first group, the self group. The first sample set most similar to the class below the class to which it belongs belongs to the second group, and the first sample set most similar to the class above the class to which it belongs belongs to the third group. Naturally the first
Many first samples fall into the group.

Next, the second sample corresponding to the first sample of each group
A near-infrared spectrum of the sample is obtained, a standard spectrum obtained by averaging the absorbances of the same wavelength is obtained, the standard spectrum of the first group is the first standard spectrum, that of the second group is the second standard spectrum, and that of the third group. This is the third standard spectrum. That is, the first to third standard spectra are set for each grade.

For polished rice as a sample to be measured, a first sample and a second sample are prepared and irradiated with near infrared light to obtain a first spectrum and a second spectrum. The first spectrum is compared with the standard spectrum of each grade to find the most similar standard spectrum, and the grade of this standard spectrum is used as the initial grade. Next, the similarity between the second spectrum and the first to third standard spectra of the initial grade is examined to determine the most similar standard spectrum. If the most similar spectrum is the first standard spectrum, the initial grade is the grade of the sample to be measured. For the second standard spectrum, the grade is one step below the initial grade, and for the third standard spectrum, the grade is one step above the initial grade. This is because the grade difference due to the first sample is small, so even if there is a deviation,
It is sufficient to correct the grade. If the initial grade is the lowest grade, the grade below is the initial grade, and if the initial grade is the highest grade, the grade above is the initial grade. As a result, even if the initial grade by the first sample is incorrect, it is corrected by the second sample to the correct grade.

FIG. 3 is a diagram showing the relationship between the standard spectra of the first sample and the second sample of this embodiment. The standard spectra of the first sample are S1 to S5 (the grades are 1 to 5), and the standard spectra of the second sample are three or two for each S1 to S5. For example, for S3, the first standard spectrum S3M corresponding to the same grade as S3, the second standard spectrum S3D corresponding to the grade one step below this, and the third standard spectrum S3U corresponding to the grade one step above S3M. Is provided. However, S
1D is S1M and S5U is S5M.

In the present embodiment, any one of the three methods described in the first embodiment may be used as the method for checking the similarity between the two spectra.

In the above-described first to third embodiments, the sample,
The absorbance for all wavelengths was measured every 2 nm for the standard spectra and each spectrum of the first sample and the second sample.
If a wavelength that can explain the grade can be detected, the absorbance at that wavelength may be measured. For example, when limited to domestic non-glutinous rice, a wavelength between 1710 and 1730 nm may be used. By limiting the number of wavelengths in this way, the measurement of the absorbance and the calculation of the similarity become very simple.

[0055]

EFFECTS OF THE INVENTION As is clear from the above description, according to the present invention, the surface layer portion showing the taste of polished rice is irradiated with near-infrared light, and the spectrum obtained is preliminarily determined by a sensory test to determine the taste grade. As compared with the standard spectrum of the surface layer of the sample, the grade of the standard spectrum with the highest degree of similarity is used as the grade of the sample to be measured, so that the grade representing the taste of rice can be accurately estimated. In addition, the surface layer portion is used as the first sample, and the remainder excluding this is used as the second sample. First, the initial grade is estimated with the first sample, and then the initial grade is corrected with the second sample. Even if it is large, the magnitude can be correctly estimated again.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a near infrared light measuring device.

FIG. 3 is a diagram showing the relationship between the grades of the standard spectra of the first sample and the grades of the first to third standard spectra of the second sample.

[Explanation of symbols]

1 sample rice 2 Near infrared light measuring instrument 3 Spectrum calculation section 4 Grade data storage 5 Grade calculator 6 Display

─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-3-242537 (JP, A) JP-A-2-290537 (JP, A) JP-A-56-162183 (JP, A) JP-A-6- 313754 (JP, A) JP-A-8-102892 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01N 21/00-21/01 G01N 21/17-21/61 PATOLIS

Claims (4)

(57) [Claims] 1. Prepared a plurality of samples of milled rice of each grade for which the grade representing the taste based on a sensory test is known, and grinding the surface layer of the milled rice of each sample for each grade to make the first portion of the surface layer portion. The absorbance of each wavelength of the first spectrum obtained by irradiating the first sample with near-infrared light is obtained by preparing the sample and the remaining second sample, and the absorbance of each wavelength is measured for the first sample of the same grade. A standard spectrum composed of the average value of the absorbance of the first sample at the same wavelength is obtained for each grade, and the first spectrum of each first sample and the standard spectrum of each grade are compared for each grade, and the first sample is analyzed by itself. The first group most similar to the standard spectrum of the belonging grade, the second group most similar to the standard spectrum below the own grade, and the second group most similar to the standard spectrum above the own grade. Divided into 3 groups, each Regarding the grade, the second sample corresponding to each first sample is irradiated with near-infrared light to obtain the second spectrum, and the spectrum of the second sample corresponding to the first sample of the first group is used as the first standard spectrum, The spectrum of the second sample corresponding to the first sample of the second group is set as the second standard spectrum, the spectrum of the second sample corresponding to the first sample of the third group is set as the third standard spectrum, and polished rice of the sample to be measured is used. The surface layer is ground to prepare a first sample of the surface layer and the remaining second sample, and the first sample is irradiated with near-infrared light to obtain a first spectrum. The most similar standard spectrum is obtained by comparing with the spectrum, and the grade of this standard spectrum is used as the initial grade.
Next, the second sample is irradiated with near-infrared light to obtain a second spectrum, which is compared with the first standard spectrum, the second standard spectrum, and the third standard spectrum of the initial grade, and when the spectrum is most similar to the first standard spectrum. Is the grade of the sample to be measured, the grade that is one step below the initial grade when it is most similar to the second standard spectrum, and the grade that is one step above the initial grade when it is most similar to the third standard spectrum. A method for measuring the taste value of rice, which comprises: 2. When determining a specific wavelength for at least one of the first standard spectrum, the second standard spectrum, and the third standard spectrum, and comparing with the second spectrum of the sample to be measured, the absorbance at the specific wavelength The method for measuring the eating quality value of rice according to claim 1, wherein 3. When the initial grade is the lowest grade and the grade is one step lower than the initial grade, this is the lowest grade,
When When the top grade was a grade 1 level upper than the initial grade is characterized in that it the highest grade claim 1
Alternatively, the method for measuring the eating quality value of rice according to item 2 . 4. A spectrum or as absorbance any one of claims 1 to 3, characterized by using a second-order differential value of the intensity of the reflected light or transmitted light and second-order differential at a wavelength of
The method for measuring the taste value of rice according to the item .