JPH07104279B2 - Evaluation method of rice taste - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a taste evaluation method for scientifically performing comprehensive evaluation of rice taste.

[Conventional technology and its problems] The taste of rice is determined by the production stage such as variety, place of production, cultivation method and harvesting method, and the processing stage after harvesting such as drying, storage and rice polishing processing. Moreover, although there are various types of rice depending on the rice cooked, the taste of rice is most affected at the production stage, and then at the processing stage.

Conventionally, the comprehensive evaluation of the taste of rice is performed by a plurality of specialized examiners regarding the appearance of the cooked rice, which is related to the comprehensive evaluation of the taste.
Each comparison item such as aroma, taste, stickiness, and hardness is repeatedly compared with those of the reference rice used as the evaluation standard to see how superior or inferior it is, and the average value is taken to calculate them. It was carried out by the so-called sensory test. However, since this sensory test is performed based on the taste that varies from person to person, even if an average of multiple evaluation results by multiple examiners is taken, the evaluation value changes at different times and different places. However, it cannot be said that the value is constant and objective. In addition, the composition and physicochemical properties of rice are scientifically measured and analyzed,
Studies have been conducted to investigate the correlation with the comprehensive evaluation value of the taste obtained by the sensory test and finally to carry out the comprehensive evaluation of the taste of rice from the scientifically obtained measurement values. . As a result, among the components that make up rice, the ones that are particularly important for comprehensively evaluating the taste of rice include the content ratios of amylose and amylopectin that make up the starch quality of rice, the content ratio of protein, and the content ratio of water. It turns out to be.

In addition, the water content of white rice also has a great influence on the overall taste evaluation in relation to the viscosity and hardness of rice during cooking. If the water content of the white rice is about 15%, the rice will be cooked into perfect grains without cracking even if it is immersed in water in the pot during rice cooking, but the water content will be high.
In the case of white rice with a breaking ratio of 14%, the water absorption rate during immersion is too fast and instantly cracks in the rice grain, and soon a through crack occurs in the inside of the rice grain. Also, crushed rice absorbs water all at once as well, so it is cooked into sticky cooked rice, and because it collapses, it becomes a low-tasting cooked rice that is neither chewy nor sticky. The main reason why the water content of white rice falls below 14% is the post-harvest processing stage of rice, especially overdrying during the drying operation, and the subsequent crushing of rice during the rice polishing operation and drying due to friction heat generation. It can be said that the progress of. Therefore, in order to prevent white rice from having a water content of less than 14% and having a reduced eating quality, it is necessary to operate the dryer to prevent over-drying in the drying operation, and in the rice polishing operation, the It is necessary to control and adjust the rice milling machine so that the generation of broken rice due to wear or the like or the excessive drying due to frictional heat generation is not induced.

It should be noted that, in addition to the contents of the above-mentioned components of rice, which have a great influence on the taste of rice, that is, the contents of protein, starch, and water, the content of fats and fatty acids is small, and the lower the content, the better the taste of rice. As described above, it affects the overall evaluation of the eating quality of rice, but it can be said that the degree of the influence is not so great as the content ratio of the three components.

Normally, it is difficult for rice mills to secure a large amount of only single-brand rice that has a good taste, so there are several types or brands of rice with different tastes, for example, high-ranked rice and low-ranked rice in the overall taste evaluation. We are trying to distribute milled rice with a stable taste by mixing and to polish rice and adjusting the mixing ratio appropriately, but the selection of several brands of rice to be mixed and the determination of the mixing ratio have been done in the past. The fact is that the processing is done based on intuition based on the quality data investigated in the above, and because there is no scientific support at all, it is often the case that the polished rice does not have a stable taste as intended, Often complaints were filed by me.

From the above, it is possible to objectively perform a comprehensive evaluation of the taste of rice by scientifically measuring and analyzing the chemical constituents that make up the rice, and to identify specific famous brands that are generally said to have a good taste. The theme is to find good-tasting rice from general-brand rice, and to improve the taste of rice by mixing multiple kinds of rice with different brands or different ingredient contents.

In view of the above, the present invention measures the absorbance using near-infrared light having a wavelength at which some of the components that make up rice, which are the factors that cause differences in the taste of rice, appear significantly as a difference in absorbance of near-infrared light. ,
Based on the measured value and the taste evaluation coefficient calculated by the multiple regression analysis method of the relation between the comprehensive evaluation value of the taste of many rice and the absorbance, which were previously obtained by a sensory test for the evaluation of taste, based on the conventional rice, Comprehensive evaluation value of rice taste calculated by sensory test based on each comparison items such as appearance, fragrance, taste, stickiness, hardness, etc. is calculated and displayed, and the moisture content and polished rice yield of the rice are calculated. By calculating and displaying the overall evaluation value of the taste when at least one of them is corrected to the desired predetermined value, the moisture content or the rice yield rate that can be adjusted by artificial processing is set to the predetermined value. Then, it is a technical object to provide a taste evaluation method of rice capable of displaying an objective comprehensive evaluation value corresponding to the original evaluation value of the original taste of the rice.

[Means for solving problems]

According to the present invention, a taste evaluation coefficient is obtained from the relationship between the comprehensive evaluation value of the taste of rice obtained by sensory and the absorbance at a plurality of predetermined wavelengths that affect the evaluation value when the rice is irradiated with near-infrared light. The sample rice is irradiated with near-infrared light to measure the absorbance with respect to the plurality of predetermined wavelengths, and a comprehensive evaluation value of the taste of the sample rice is directly obtained from the absorbance and the taste evaluation coefficient. In the method for evaluating the taste of rice, the comprehensive evaluation value of the taste of the sample rice is obtained by correcting the rate to a predetermined rate for at least one of the water content rate and the rice polishing yield rate of the sample rice. There is provided a method for evaluating the taste of rice, which comprises converting the evaluation value into

According to the present invention, further, a component conversion coefficient is determined from the relationship between the content ratio of a plurality of predetermined components that influence the taste of rice and the absorbance when the rice is irradiated with near infrared light, and the component conversion coefficient is occupy in the rice. The taste evaluation coefficient is determined from the relationship between the content rate of the above components and the comprehensive evaluation value of the taste of rice obtained by sensory evaluation, and the sample rice is irradiated with near infrared light without heat treatment or chemical treatment. The absorbance is measured, the content of the plurality of predetermined components in the sample rice is obtained from the absorbance and the component conversion coefficient, and then the comprehensive evaluation value of the taste of the sample rice is obtained from the content and the taste evaluation coefficient. In the taste evaluation method, the taste evaluation value is converted into a taste evaluation value when the rate is corrected to a predetermined rate for at least one of the water content rate and the rice polishing yield rate of the sample rice. Rice food characterized by A taste evaluation method is provided.

[Action]

When the different sample rices are irradiated with near infrared light, the wavelengths at which the difference in the taste of the sample rices appears remarkably as the difference in absorbance can be seen.

The present invention utilizes this absorbance characteristic, the detection signal from the detector for detecting the absorbance of the sample rice, the comprehensive evaluation value of the taste of rice obtained by sensory and the near infrared ray irradiation of the rice. Based on the taste evaluation coefficient determined by calculating the relationship with the absorbance for a plurality of predetermined wavelengths that affect the evaluation value by the multiple regression analysis method, the total evaluation value of the taste of the sample rice is calculated and displayed, and the sample is also displayed. Based on at least one of the moisture content rate and the rice polishing yield rate of rice, the comprehensive evaluation value of the taste when the value of the sample rice is corrected to a desired value is calculated and displayed.

Example of Invention

Hereinafter, the taste evaluation method of the present invention will be described in accordance with the examples illustrated in FIGS.

FIG. 1 is a schematic view of an apparatus 1 for carrying out the rice texture evaluation method according to the present invention when viewed from the front. Cabinet 2
A near-infrared spectroscopic analysis device 3 and a control device 4 whose detailed structure is described below with reference to FIG. On the front panel of the cabinet 2, a sample container mounting box 5 for mounting a sample container 17 for containing the sample rice to be measured, a light emitting diode or a CRT type display device 6 for visually displaying the operation procedure of the device and the calculation result, An operation push button 7 and a printer 8 capable of making a hard copy of a calculation result are arranged. The control device 4 is connected to the near infrared spectroscopic analysis device 3, the display device 6, the operation push button 7, the printer 8 and the like, and the input / output signal processing device 4a for processing various signals, and calculates the taste evaluation value. The taste evaluation coefficient set for this purpose, the ingredient conversion coefficient for calculating the content rate of each ingredient, the rice price for each brand or grade entered via the input device (keyboard) 9, various correction values, and various controls A storage device 4b for storing procedures and the like, and a computing device 4c for computing a comprehensive evaluation value of rice taste based on the absorbance measurement value obtained by the near-infrared spectroscopic analysis device 3 and the taste evaluation coefficient. Consists of. The taste evaluation coefficient, the component conversion coefficient set individually for each major rice component, and the necessary correction value are stored in a read-only memory (hereinafter referred to as RO
(Hereinafter referred to as “M”), the function required for the taste evaluation apparatus 1 is simply to obtain a comprehensive evaluation value of the taste of rice, and the content ratio of each component, the optimum mixing ratio, and the predetermined value based on various setting conditions. The keyboard 9 as an input device is not always necessary when the function of obtaining the converted value corrected to the water content rate and the rice polishing yield rate is not required. Further, the printer 8 is not limited to the built-in type, and may be the external connection type.

FIG. 2 is a cross-sectional view of a main part of one embodiment of the near-infrared spectroscopic analyzer 3 arranged inside the cabinet 2. The illustrated near-infrared spectroscopic analyzer 3 is of a reflection type, and has a light source 10, a reflecting mirror 11, a narrow band transmission filter 12, an integrating sphere 13, and detectors 14a and 14b as main components. Light source 10
The near-infrared light emitted from, and converted into parallel rays through an appropriate optical system (not shown) becomes near-infrared monochromatic light of a specific wavelength by passing through the narrow band transmission filter 12,
Reflector 11 configured to change the tilt angle freely
Allows the daylighting window 15 provided by opening the upper part of the integrating sphere 13.
Redirected towards. Thus, the near-infrared monochromatic light that has entered the inside of the integrating sphere 13 is a sample container equipped with the grain temperature detector 23 from the measuring unit 16 provided by opening the bottom of the integrating sphere 13.
The sample rice 18 in 17 is irradiated from directly above. Diffuse reflected light from the sample rice 18, while reflecting on the inner wall of the integrating sphere 13, finally arrives at the pair of detectors 14a, 14b arranged symmetrically with respect to the measuring unit 16, Thereby, the intensity of the reflected light is measured. Although two detectors are provided in this embodiment, the number of detectors is not limited to two, and may be one or three or more.

Here, the configuration of the narrow-band transmission filter 12 provided between the light source 10 and the reflecting mirror 11, which becomes a near-infrared monochromatic light of a specific wavelength by transmitting the light emitted from the light source 10 and a request for this The physical characteristics and the like that are performed will be described. The narrow band transmission filter 12 is an arbitrary plurality of filters each having different main wavelength transmission characteristics, for example, six filters 12a to 1
2f, which are attached to a rotating disk and rotated by an appropriate angle so that desired filters 12a to 12f can be sequentially selected and exchanged so that the desired filters 12a to 12f are positioned on the line connecting the light source 10 and the reflecting mirror 11. And The dominant wavelength in the transmission characteristics of the filter is the maximum transmission wavelength of the near-infrared light that is transmitted when the incident optical axis is perpendicular to the surface of the filter. As another specific configuration example of the narrow band transmission filter 12, the light source 10 and the reflecting mirror 22 are located inside, and a plurality of filters 12a to 12f are configured in a prismatic shape, and the filter 12a to 12f is configured with a central point P by an electric motor 19 or the like. There is also a configuration in which it can be rotated about the axis (see FIG. 3). In addition, the inclination angle of the rotation surface with respect to the incident optical axis of the narrow band transmission filter 12,
If it is possible to finely and continuously adjust by the electric motor 19 or the like, near-infrared monochromatic light of different wavelengths shifted from the main wavelength of the transmission characteristics of each filter can be continuously produced.

Next, the physical characteristics required for the narrow band transmission filter 12 will be described with reference to FIG. FIG. 4 is a graph (absorbance curve) showing the relationship between the irradiation wavelength and the absorbance when different sample rices are irradiated with near-infrared light whose wavelength continuously changes. The absorbance log I ₀ / I is the common logarithm of the reciprocal of the ratio of the reflected light amount I from the sample rice to the reference irradiation light amount (total irradiation light amount) I ₀ . The curve A shown by the solid line shows the absorbance in the case of Nipponbare in Table 1 above, the curve B shown by the dashed line shows the Koshihikari curve, and the curve C shown by the dotted line shows the absorbance curve in the case of Ishikari. From the figure, the short-wavelength region of near-infrared light of 1900 nm or less is a low absorbance region, and there is a slight difference in the absorbance difference with respect to the content of each component constituting rice such as amylose, protein, and water. , With a wavelength of 1900 nm as the boundary, it becomes a high absorbance range,
It can be easily understood that the difference in the content of each of the above components remarkably appears as a difference in absorbance. Since the present invention elucidates this phenomenon and uses it to measure the taste difference of rice of different qualities, the wavelength of the near-infrared monochromatic light with which the rice is irradiated for the measurement is in the wavelength range. Of 1900-2500 nm,
A specific peak is seen on the absorbance curve for each component, for example 1940m, 2100nm, 2180nm, 2230nm, 2280nm, 2310nm
Are suitable. Therefore, a narrow band transmission filter
Each of the filters 12a to 12f included in 12 has a difference in taste, that is,
In order to produce near-infrared monochromatic light of each wavelength suitable for measuring each component of rice, it is required to have each wavelength as a main wavelength.

Next, a specific operation in the above embodiment will be described. First, the near-infrared spectroscopic analyzer is operated until the light source 10 is turned on by operating the operation push button 7 and the near-infrared monochromatic light of the specific wavelength reaching the measuring unit 16 based on the light emitted from the light source 10 is stabilized. After preheating the whole of No. 3, the sample container 17 containing the sample rice is placed at a predetermined position directly below the measuring unit 16 of the near-infrared spectroscopic analyzer 3, and the measurement preparation is completed.

After the measurement preparation work is completed, first, the filter 12a having the main wavelength of 1940 nm is selected so as to be on the line connecting the light source 10 and the reflecting mirror 11 (see FIG. 2), and the wavelength is set.
Measurement work of reflection absorbance when the sample rice 18 was irradiated with 1940 nm near-infrared monochromatic light. The measurement work of the reflection absorbance is performed by measuring the total irradiation light amount irradiated to the sample rice 18, that is, the reference irradiation light amount, and actually reflecting it on the sample rice 18 when the reference irradiation light amount is irradiated to the sample rice 18. Measurement of the amount of reflected light. Either of these two measurements may be performed first for one filter, but in the following description, the measurement of the reference irradiation light amount will be performed first. To measure the reference irradiation light amount, the tilting angle of the reflecting mirror 11 having a variable tilting angle is set to such an angle that these reflected lights directly hit the inner wall of the integrating sphere 13 by using a rotating means (such as an electric motor). (Not shown) is performed in a changed state. By doing so, the light from the reflecting mirror 11 directly applied to the inner wall of the integrating sphere 13 is diffused and reflected on the inner wall in multiple directions, and finally the detectors 14a, 14b.
And is detected as the reference irradiation light amount. On the other hand, the amount of reflected light from the sample rice 18 is measured by the above-described principle after the tilt angle of the reflecting mirror 11 is returned to the original position shown in FIG. After the preparation for measurement, the first filter selection, the measurement of the reference irradiation light amount, and the measurement of the reflected light amount are performed by storing the procedure program in the ROM in the storage device 4b of the control device 4 and automatically executing the procedure program according to the program. It goes without saying that you can make it happen. In addition, it is also useful to improve the measurement accuracy that the reference irradiation light amount and the reflected light amount of one filter are measured a plurality of times so that the average thereof can be taken as the measurement value. Each measured value based on the reference irradiation light amount detected by the detectors 14a and 14b and the reflection light amount from the sample rice 18 is communicated to the control device 4 as actual measurement data, and a writable memory (hereinafter referred to as RAM) in the storage device 4b. Once said).

When the measurement of the absorbance at the irradiation wavelength of 1940 nm is completed, the process proceeds to the measurement of the absorbance at the next irradiation wavelength, that is, 2100 nm in the case of this example. Here, too, the measurement of the reference irradiation light quantity is as described above.
The same method and procedure is performed as at 1940 nm. As in the previous time, each measured value is communicated to the control device 4 as actual measurement data for calculating the content rate of each component, and stored in the storage device 4b.
Temporarily stored in RAM. Similarly in the following, each absorbance measurement at the remaining irradiation wavelength, that is, the wavelength 2180nm, 2230nm, 2280nm, 2
The absorbance measurement at 310 nm is sequentially performed, and each measurement value is communicated to the control device 4 as actual measurement data and stored in the RAM.

In addition, the replacement / selection operation of each filter 12a to 12f of the narrow band transmission filter 12 accompanying the transition to the absorbance measurement at the next specific wavelength after the measurement of the absorbance at a certain specific wavelength is normally performed by the memory of the control device 4. Although it is automatically performed according to the procedure program written in advance in the ROM in the device 4b, even in the case of the present embodiment, it is not always necessary to perform the absorbance measurement for all the above 6 wavelengths, and it is the object of measurement. The wavelength can be arbitrarily selected in consideration of the accuracy required for the taste evaluation value to be obtained or the time required for the measurement, and the selection can be made by the measurement wavelength selection button in the operation push button 7. it can.

The above-described measurement of absorbance is performed by simply replacing the six filters 12a to 12f set in the narrow band transmission filter 12 in order to measure the spot-like absorbance at each main wavelength of each filter 12a to 12f. Although it was a method, 90 ° which is the standard of the incident angle of the incident light on the surface of the filter
, The maximum transmission wavelength shifts in the range of several tens of nm from the main wavelength, making continuous absorption measurement in the wavelength region 1900 to 2500 nm in which the difference in eating quality of rice significantly appears in the absorbance difference. Is also possible. In the case of the first embodiment (second
(Refer to the figure), Narrow band pass filter 12 configured in the shape of a disk
This can be done by gradually and continuously changing the angle of the incident optical axis on the optical axis by an appropriate adjusting means (not shown) such as an electric motor based on a command signal from the control device 4.

Next, the arithmetic unit 4c of the control device 4 uses a large amount of actual measurement data obtained by the absorbance measurement stored in the RAM of the storage device 4, that is, the measured values of the reference irradiation light amount and the reflected light amount at each measurement wavelength, and the storage device. The total evaluation value of the taste of rice is calculated based on the taste evaluation coefficient for calculating the taste evaluation value stored in the ROM of 4 in advance.

The taste evaluation coefficient pre-written in the ROM of the storage device 4 is the absorbance measurement value from the detector based on the comprehensive evaluation value of the taste obtained by the sensory test method for many sample rices. It is a constant obtained by signal processing and calculation by the multiple regression analysis method.

Here, an example of multiple regression analysis is shown. For example, 6 filters with different wavelengths λ ₁ = 1940nm, λ ₂ = 2100nm, λ ₃ = 2180n
When m, λ ₄ = 2230 nm, λ ₅ = 2280 nm, λ ₆ = 2310 nm are used, the following linear relationship is established.

Ta = F ₀ + F ₁ · X ₁ a + F ₂ · X ₂ a + F ₃ · X ₃ a + F ₄ · X ₄ a + F ₅
・ X ₅ a + F ₆・ X ₆ a + C Ta is the overall evaluation value of taste measured by sensory test method for sample a.

F _{0 to} F ₆ are coefficient values obtained by this multiple regression analysis.

X ₁ a to X ₆ a correspond to the filter numbers of λ ₁ to λ ₆ , respectively, and are the absorbances (log I ₀ / I) of sample a measured with a near-infrared spectroscopic analyzer.

C is an error term, and here C = 0.

For sample a (assuming solid line in Fig. 4), X ₁ a = 0.6
1, X ₂ a = 0.60, X ₃ a = 0.56, X ₄ a = 0.53, X ₅ a = 0.65, X ₆ a
= 0.67, and the multiple regression equation is Ta = F ₀ + 0.61F ₁ + 0.60F ₂ + 0.56F ₃ + 0.53F ₄ + 0.65F ₅ +0.
It becomes 67F ₆ . Similarly, the absorbance can be substituted into the multiple regression equation for up to n samples to obtain the following taste evaluation coefficient.

T = 144.7 + 234.6X ₁ + 6371X ₂ -1122X ₃ + 303.7X ₄ -536.4
X in ₅ -4969X ₆ ... (1) The same procedure as taste evaluation coefficient, amylose is a major component constituting the rice, protein, water, can be determined as necessary the content of fat and the like. For example, the component conversion coefficient of amylose is based on the content measured using a large number of samples by a chemical quantitative analysis method, for example, an iodine colorimetric colorimetric method or an iodine amperometric titration method, and an arbitrary detected value from the light receiving element is used. The signal processed value and the value are obtained using the multiple regression analysis method.

Here is an example. For example, five filters with different wavelengths λ ₁ = 2100nm, λ ₂ = 2180nm, λ ₃ = 2230nm, λ ₄
= 2280 nm, λ ₅ = 2310 nm is used, the following linear relationship is established.

In the amylose measurement, the wavelength of 1940 nm in which the change in the water content is markedly shown as the difference in absorbance is excluded.

Aa = F ₀ + F ₁ · X ₁ a + F ₂ · X ₂ a + F ₃ · X ₃ a + F ₄ · X ₄ a + F ₅
・ X ₅ a + C Aa is the amylose content percentage measured by the chemical quantitative analysis method for sample a.

F _{0 to} F ₅ are coefficient values obtained by this multiple regression analysis.

X ₁ a to X ₅ a correspond to the filter numbers of λ ₁ to λ ₅ , respectively, and the absorbance (log I ₀ / I) of sample a measured by a near-infrared spectroscopic analyzer.

C is an error term, and here C = 0.

In the case of sample a (assuming the solid line in FIG. 4), X ₁ a = 0.
60, X ₂ a = 0.56, X ₃ a = 0.53, X ₄ a = 0.65, X ₅ a = 0.67, and the multiple regression equation is Aa = F ₀ + 0.60F ₁ + 0.56F ₂ + 0.53F ₃ +0 It becomes .65F ₄ + 0.67F ₅ . Similarly, the component conversion coefficient for obtaining the amylose content shown below can be obtained by substituting the absorbance into the multiple regression equation for up to n samples.

_{A = 33.3 + 2380X 1 -2300X 2} -640X 3 + 1405X 4 -880X 5 ...
(2) In the above calculation formula (1), F _{0 to} F ₆ (F ₀ = 144.7, F ₁ = 23
4.6, F ₂ = 6371, F ₃ = -1122, F ₄ = 303.7, F ₅ = -536.4, F ₆ =
-4969) is a taste evaluation coefficient which is stored in advance in the ROM of the storage device 4b or is input to the control device 4 via the input device 9 when calculating the taste evaluation value for measuring the sample, The formula (1) is suitable for the average Japanese to evaluate the taste of Japanese rice, but this taste evaluation coefficient has different standard tastes depending on the region or country in which the rice is eaten. In some cases, different numbers may be appropriate.

In the above calculation formula (2), F _{0 to} F ₅ (F ₀ = 33.3, F ₁ = 238
0, F ₂ = 2300, F ₃ = −640, F ₄ = 1405, F ₅ = −880) is stored in advance in the ROM of the storage device 4b, or via the input device 9 when measuring the sample. This is a component conversion coefficient for calculating the component content rate that is input to the control device 4.

The tasting evaluation value T calculated according to the above formulas (1) and (2) and the respective content rates of the respective components such as amylose, protein and water which are the main components of rice are calculated by the arithmetic unit 4c. At the same time, while being visually displayed on the display device 6, a hard copy of each calculated value is sent out from the printer 8 automatically or based on a command to the operation push button 7. Then, if the moisture content and the rice polishing yield of the sample rice measured by the known measuring means and the desired predetermined moisture content and the rice polishing retention are input to the input device 9, the predetermined moisture is obtained. The taste evaluation value corrected to the content rate and the rice polishing yield rate is visually displayed on the display device 6, and a hard copy is fed from the printer 8. Correction for water content
If the water content rises or falls by 1% around 15.5%, the original taste evaluation value will decrease by 0.05, and the rice polishing yield will increase by 90%. 0 for the value.
It was experimentally found that the rate of change decreased and the rate of change was approximately proportional. Regarding the content of amylose, the content ratio with amylopectin, which constitutes starch together, is more important than the content ratio of amylose itself. Therefore, it is preferable to display the content ratio instead of the content ratio. Further, after measuring the content rate of the main components that make up the rice, the overall evaluation of the taste is performed by the respective content rates and the overall evaluation value of the taste by the sensory test of the known rice and the taste evaluation coefficient calculated by each content rate. The method of obtaining the value can obtain almost the same numerical value as the method of the present invention. As an example, Tx = 5 × 10 ⁶ / (A × P ^0.3 × 7.8 K) ² K = 6 × 10 ⁻³ M ² −0.18M + 2.43.

Here, A is the amylose content percentage, P is the protein content percentage, and M is the water content percentage value.

In the above-mentioned taste evaluation device, the reflection-type near-infrared spectroscopic analysis is carried out by measuring the intensity of light when the sample rice is irradiated with near-infrared monochromatic light of a specific wavelength, by measuring the intensity of the reflected light from the sample rice. Although the device was used, as shown in FIG.
The bottom of 13 is formed of a transparent glass plate 13a, and a detector 21c is arranged below the measurement unit 23 to measure the intensity of transmitted light that has passed through the sample rice, and the transmission type near infrared spectroscopy is performed. An analyzer can also be used. Furthermore, a more precise near-infrared spectroscopic analyzer that measures absorbance based on both reflected light and transmitted light can be used.

In the above description, of the amylose and amylopectin that compose the starch, the description was based on the analysis of amylose, but instead of amylose, the content ratio of amylopectin was measured,
The component conversion coefficient of amylopectin can be set in the equation (2).

〔The invention's effect〕

As described in detail above, according to the taste evaluation device for rice according to the present invention, anyone can perform sensory tests based on taste with individual differences, or time-consuming, skill-based chemical quantitative analysis and other methods. It is possible to easily and accurately obtain a comprehensive evaluation value of rice taste, and taste when the moisture content of rice and / or rice polishing yield is corrected to a desired value. By calculating and displaying the evaluation value, when comparing the comprehensive evaluation of the taste of various rice, the moisture content and the rice polishing yield rate that can be adjusted by artificial processing are set to predetermined values, and the original rice It is possible to secure high accuracy of the comprehensive evaluation value of the taste of.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention, and FIG.
Fig. 3 is a schematic cross-sectional view of a main part of the near-infrared spectroscopic analyzer, Fig. 3 is a schematic cross-sectional view of a main part of the other embodiment, and Fig. 4 is a relationship between near-infrared light irradiation wavelength and absorbance for rice of different brands. Is a graph (absorbance curve) showing In the figure, 1 ... rice taste evaluation device, 2 ... cabinet,
3 ... near infrared spectroscopy analyzer, 4 ... control device, 4a ... input / output signal processing device, 4b ... storage device (ROM, RAM), 4c ...
… Computing device, 5 …… Sample container mounting box, 6 …… Display device,
7 ... Operation push buttons, 8 ... Printer, 9 ...
… Input device, 10 …… Light source, 11 …… Reflector, 12 …… Narrow band transmission filter, 12a-12f …… Narrow band transmission filter,
13 ... integrating sphere, 14a, 14b, 14c ... detector, 15 ... daylighting window, 16 ... measuring part, 17 ... sample container, 18 ... sample rice, 19
...... Motor, 20 …… Transparent glass, 21 …… Detector, 22 ……
Reflector, 23 ... Grain temperature detector.

Claims (15)

[Claims] 1. A taste evaluation coefficient is calculated from the relationship between the comprehensive evaluation value of the taste of rice obtained by sensory evaluation and the absorbance at a plurality of predetermined wavelengths that affect the evaluation value when the rice is irradiated with near infrared light. Specified, the sample rice is irradiated with near infrared light to measure the absorbance with respect to the plurality of predetermined wavelengths, and a comprehensive evaluation value of the taste of the sample rice is directly obtained from the absorbance and the taste evaluation coefficient. In the method for evaluating the taste of rice, the comprehensive evaluation value of the taste of the sample rice is obtained by correcting the rate to a predetermined rate for at least one of the water content rate and the rice polishing yield rate of the sample rice. A method for evaluating the taste of rice, which comprises converting the evaluation value. 2. A component conversion coefficient is determined from the relationship between the content of a predetermined component that influences the taste of rice and the absorbance when the rice is irradiated with near infrared light, and the sample rice is exposed to near infrared light. The method for evaluating the taste of rice according to claim (1), wherein the content of the predetermined component in the sample rice is calculated and displayed from the absorbance measured by irradiation and the component conversion coefficient. 3. A moisture content conversion coefficient is determined from the relationship between the moisture content of rice and its absorbance when the rice is irradiated with near infrared light, and the sample rice is irradiated with near infrared light for measurement. The moisture content of the sample rice was calculated from the absorbance and the moisture content conversion coefficient, and based on this moisture content, a comprehensive evaluation value of the taste of the sample rice was calculated based on a predetermined moisture content of the sample rice. Claim (1) to be converted into an evaluation value when corrected to a rate
Item or the method for evaluating the taste of rice according to item (2). 4. The rice according to any one of claims (1) to (3), wherein the light reflected from the sample rice is received to measure the absorbance of near infrared light by the sample rice. Taste evaluation method. 5. The method according to claim 1, wherein the absorbance of near infrared light by the sample rice is measured by receiving the light transmitted through the sample rice.
Item 6. The method for evaluating the taste of rice according to any one of Items (3) to (3). 6. The light absorption of near infrared light by the sample rice is measured by receiving the light reflected from the sample rice and the light transmitted through the sample rice. The method for evaluating the taste of rice according to any one of 1. 7. The method for evaluating the taste of rice according to any one of claims (1) to (6), wherein the sample rice is unmilled brown rice grain or white rice grain. 8. The method of evaluating the taste of rice according to any one of claims (1) to (6), wherein the sample rice is pulverized into powder. 9. A component conversion coefficient is determined from the relationship between the content of a plurality of predetermined components that affect the taste of rice and the absorbance of the rice when it is irradiated with near-infrared light. The taste evaluation coefficient is determined from the relationship between the content rate and the comprehensive evaluation value of rice taste obtained by sensory evaluation, and the absorbance is measured by irradiating near-infrared light on the sample rice without heat treatment or chemical treatment. Then, the content rate of the plurality of predetermined components in the sample rice is obtained from the absorbance and the component conversion coefficient, and then the taste evaluation of rice is obtained from the content rate and the taste evaluation coefficient to obtain a comprehensive evaluation value of the taste of the sample rice. In the method, the taste evaluation value is converted into a taste evaluation value when the rate is corrected to a predetermined rate for at least one of the water content rate and the rice polishing yield rate of the sample rice. How to evaluate the taste of rice. 10. The method for evaluating the taste of rice according to claim 9, wherein the content of the predetermined component is displayed. 11. The taste evaluation method for rice according to claim 9, wherein the light reflected from the sample rice is received to measure the absorbance of near infrared light by the sample rice. 12. The taste evaluation method of rice according to claim 9, wherein the absorbance of near infrared light by the sample rice is measured by receiving the light transmitted through the sample rice. 13. The taste evaluation of rice according to claim 9, wherein the absorbance of near infrared light by the sample rice is measured by receiving the light reflected from the sample rice and the light transmitted through the sample rice. Method. 14. The method for evaluating the taste of rice according to any one of claims (9) to (13), wherein the sample rice is unmilled brown rice grain or white rice grain. 15. The method for evaluating the taste of rice according to any one of claims (9) to (13), wherein the sample rice is pulverized into powder.