JP2892084B2 - Rice quality evaluation method and rice quality evaluation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a quality evaluation method for evaluating the quality of rice, more specifically, measuring the content of predetermined components contained in rice,
The present invention relates to a method for evaluating rice quality based on the measured values.

[Conventional technology and its problems]

The quality of rice, especially its taste, is determined at the production stage such as selection of quality, production area, cultivation method, harvest method, drying,
It is determined at the stage of post-harvest processing such as storage and rice processing, and well, it is affected at the time of rice processing, but it is the production stage that affects the taste of rice most. Next, the processing stage.

Conventionally, quality evaluations of rice, especially evaluations of taste, have been conducted by several expert examiners in terms of the appearance, aroma,
A so-called sensory test is conducted by repeatedly testing each comparative item such as taste, stickiness, and hardness with respect to those of a reference rice as an evaluation standard to determine how superior or inferior it is, and taking an average value. It was done. However, since this sensory test is performed based on tastes that vary from person to person, even if the average of multiple evaluation results by multiple examiners is taken, the evaluation value changes at different times and places. However, it is not a constant objective and absolute value. In addition, scientifically measure and analyze the composition and scientific properties of rice,
A study was conducted to investigate the correlation between the taste evaluation values obtained in the sensory tests described above, and finally to evaluate the quality of rice from scientifically obtained measurement values. It has been found that among the constituent components, those which are particularly important in evaluating the quality of rice are the content ratio of amylose and amylopectin, the protein content and the water content constituting starch of rice.

Next, it will be described how the magnitude of the content of each component constituting rice affects the quality of rice, particularly its taste.

Generally, Koshihikari and Sasanishiki are popular brands with good taste in Japan. For example, Koshihikari and several brands of rice, including Sasanishiki, are compared with the protein content of white rice of each standard milling degree and the amylose content of starch, as shown in Table 1 below. Become. Note that the content of each component is not always the same as shown in the table for the same brand, but also depends on the geological conditions (soil and water quality) of the cultivated production area, and also on the weather conditions (temperature, sunshine hours). , Rainfall, etc.), it goes without saying that the content of each component slightly changes.

According to Table 1 above, the main factors that make Koshihikari and Sasanishiki good in taste are that the protein content is low and the amylose content ratio in starch is low compared to other general brand rice. I can understand.

As described above, apart from the fact that the protein content and the amylose content ratio in the starchy substance have a great influence on the taste of rice, and thus on the quality of rice, the water content of white rice also has a high quality,
In particular, it has a great influence on the taste in relation to the viscosity and hardness of rice during cooking. When the white rice has a water content of about 15%, even if it is immersed in the water of a rice cooker, the rice does not crack and cooks into complete rice grains, but if the water content is less than 14%, the rice is immersed. When the water absorption rate is too fast, the rice grains crack instantaneously,
Shortly afterwards, a penetrating crack will be formed in the inside of the rice grain, so that it absorbs water in the cracks and releases glue from the cracks. There will be no low quality cooked rice. The main reason why the moisture content of white rice falls below 14% is the excessive drying in the post-harvest processing stage, especially in the drying operation, followed by the generation of broken rice and the drying due to frictional heating in the milling operation. It can be said that the progress of. Therefore, the moisture content is 14%
In order to prevent the white rice from deteriorating in quality, it is necessary to operate the dryer in the drying operation to prevent excessive drying, and in the polishing operation, the generation of broken rice due to wear of parts or the like It is necessary to control and adjust the rice mill so as not to induce excessive drying due to frictional heating.

In addition, the above ingredients of rice that have a great effect on the quality of rice,
In other words, besides the contents of protein, starch, and water, the contents of fats and fatty acids, and the lower the content, the better the taste of rice. It can be said that the degree of the influence is not so large as to the degree of the content of the three components.

Usually, in a rice mill, it is difficult to secure a large quantity of high quality single brand rice alone.Therefore, several kinds or several brands of rice having different quality, such as a high rank rice and a low rank rice of quality evaluation. Rice is mixed and polished, and the mixing ratio is adjusted appropriately to promote the distribution of polished rice with stable quality.However, selection of several types of rice to be mixed and determination of the mixing ratio have been investigated in the past. The fact is that the processing is performed based on intuition based on quality data, and there is no scientific support at all, and in many cases, the milled rice does not have the desired quality and stable rice. It was often raised.

On the other hand, it has been empirically known that when rice is cooked by adding a small amount of mochi rice to glutinous rice (general white rice), the viscosity of the cooked rice is increased and the taste is improved. The following can be said in terms of the relationship. Starch is composed of amylose and amylopectin. As the content of amylose in starch increases, the taste of rice tends to decrease as described in connection with Table 1 above. Therefore, if rice is cooked by adding a small amount of waxy rice having amylopectin content of almost 100% to general glutinous rice having amylopectin content ratio of about 78% in starchy substance, the amylopectin content ratio is high, that is, The taste is improved almost as much as the taste of rice having a low amylose content. However, when the content ratio of amylopectin exceeds a certain level, the viscosity becomes too strong, and conversely, the taste of rice is reduced.

Based on the above, the chemical composition of rice is measured and analyzed scientifically to objectively evaluate the quality of rice and to be caught by certain well-known brands that are generally considered to be of good quality. The theme is to find good quality rice among common brand rice, and to improve the quality or taste of rice by mixing multiple types of rice with different brands or different component contents. .

In view of the above, the present invention measures the content of a predetermined component contained in rice in a short time, and based on the measured value and a specific coefficient for quality evaluation set in accordance with the component, the quality of rice. It is a technical object to provide a method for evaluating rice quality that can calculate and display an evaluation value.

[Means for solving the problem]

The near-infrared spectrometer that measures the content of the component that affects the taste of rice as a difference in absorbance is used to measure the absorbance of the sample rice, and the absorbance and a predetermined component conversion coefficient are used to determine a predetermined amount of rice contained in the rice. A rice quality evaluation method in which the content of components is calculated and the quality of sample rice is evaluated based on the content of components. The crushed sample rice is crushed, and the absorbance of the crushed sample rice is measured by the near-infrared spectrometer to calculate the content of a predetermined component.

[Action]

When a different sample of rice is irradiated with near-infrared light, a wavelength is observed at which the content of the components constituting the rice appears more or less as an absorbance difference.

The present invention utilizes this absorbance characteristic, the detection signal from the detector that detects the absorbance difference, and the component content of a large number of rice whose component content has been accurately measured in advance in calculating the content of the component to be measured. Based on the component conversion coefficient value calculated with the absorbance, and the specific coefficient calculated based on the quality evaluation value of many rice and the component content calculated in advance by a sensory test for calculating the quality evaluation value, a certain particle size is obtained. The content of the component to be measured and the quality evaluation value of the selected sample rice are calculated and displayed.

(Example of the invention)

Hereinafter, the apparatus and the working method used in the present invention will be described with reference to FIGS. 1 to 6.

FIG. 1 is a schematic view of the rice quality evaluation device 1 according to the present invention when viewed from the front. Inside cabinet 2
The near-infrared spectroscopic analyzer 3 and the control device 4 described in detail with reference to FIG. On the front panel of the cabinet 2, a sample container mounting box 5 for mounting a sample container for putting the sample rice to be measured, a light emitting diode or CRT type display device 6 for visually displaying operation procedures and calculation results of the apparatus, A push button 7 and a printer 8 that enables a hard copy of the calculation result are provided. The control device 4 includes an input / output signal processing device 4a connected to the light source and the detector of the near-infrared spectroscopic analyzer 3, the display device 6, the operation push button 7, the printer 8, and the like for processing various signals; Component conversion coefficient value for calculating each component content, specific coefficient individually set for each major component of rice to calculate quality evaluation value, input device (keyboard)
US price by brand or grade, entered via 9
A storage device 4b for storing various correction values, various control procedures, and the like, and a calculation device for calculating a rice quality evaluation value and the like based on the measurement value obtained by the near-infrared spectroscopic analyzer 3 and the specific coefficient. 4c. The specific coefficients and necessary correction values that are set individually for each major component of rice are stored in the storage device.
4b is stored in advance in a read-only memory (hereinafter referred to as a ROM), and the function required for the quality evaluation device 1 is to simply obtain a rice quality evaluation value. When the function for obtaining the ratio is not required, the keyboard 9 as the input device is not always necessary. Further, the printer 8 is not limited to the built-in type, but may be an external connection type.

A supply hopper 10 for charging sample rice is mounted on an upper portion of the cabinet 2, and is connected to a lower end of the supply hopper 10, and the sample rice grain sorting apparatus 11 is provided. Grain sorting equipment
Below 11 is provided a sample crusher 12 for crushing the sample rice into fine grains, and below the sample crusher 12, the sample container 13 is moved to a position immediately below the measuring section of the near-infrared spectroscopic analyzer 3. A sample supply device including a sample rice transport device 14 to be moved is provided.

Reference numeral 15 denotes a receiving box for receiving unnecessary sample rice after the sample rice crushed by the sample crushing device is filled in a required amount in the sample container 13 and a sample discharged after the measurement is completed. Can be inserted and removed from the front panel.
Reference numeral 16 denotes an external supply unit for independently supplying sample rice to the measurement unit from outside.

FIG. 2 is a cross-sectional view of a main part of an embodiment of the near-infrared spectroscopic analyzer 3 disposed inside the cabinet 2. The illustrated near-infrared spectroscopic analyzer 3 is of a reflection type, and includes, as main components, a light source 17, a reflecting mirror 18, a narrow band-pass filter 19, an integrating sphere 20, and detectors 21a and 21b. Light source 1
The near-infrared light emitted from 7 and converted into a parallel light through an appropriate optical system (not shown) is passed through a narrow band-pass filter 19.
After passing through the near-infrared monochromatic light of a specific wavelength, the reflecting mirror 18 configured so that the inclination angle can be freely changed, the lighting window 22 provided by opening the upper part of the integrating sphere 20 The direction is changed toward. Thus, the integrating sphere 20
The near-infrared monochromatic light entering the inside of the sample irradiates the sample rice 24 in the sample container 3 from directly above from a measuring unit 23 provided with an opening at the bottom of the integrating sphere 20. The diffusely reflected light from the sample rice 24, while being reflected on the inner wall of the integrating sphere 20, eventually reaches a pair of detectors 21a and 21b disposed at target positions around the measurement unit 23, Thereby, the intensity of the reflected light is measured. In addition,
Although two detectors are provided in the present embodiment, the number is not limited to two and may be one or three or more.

Here, the light source 17 is provided between the light source 17 and the reflecting mirror 18.
The configuration of the narrow band-pass filter 19 which becomes a near-infrared monochromatic light of a specific wavelength when light emitted from the filter passes therethrough, and physical characteristics required for the filter will be described. The narrow band-pass filter 19 is an arbitrary number of filters each having a different dominant wavelength pass characteristic, for example, six filters 19a.
These are mounted on a rotating disk, and are rotated by an appropriate opening degree, so that a light source 17 and a reflecting mirror 18 are provided.
And the filters can be sequentially selected and replaced such that the desired filters 19a to 19f are positioned in a line connecting the lines. The dominant wavelength in the transmission characteristics of the filter is the maximum transmission wavelength of near infrared rays transmitted when the incident optical axis is perpendicular to the surface of the filter. As another specific configuration example of the narrow band pass filter 19, the light source 17 and the reflecting mirror 18 are located inside, and a plurality of filters 19a to 19f are configured in a prism shape,
There is also a configuration in which this can be rotated around the center point P by means such as a motor 25 (see FIG. 3). If the inclination angle of the rotating surface of the narrow band pass filter 19 with respect to the incident optical axis can be finely and continuously adjusted by means such as an electric motor, the shift characteristic is shifted from the main wavelength of the pass characteristic of each filter. Near-infrared monochromatic light of different wavelengths can be continuously produced.

Next, physical characteristics required for the narrow band pass filter 19 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 rice is irradiated with near-infrared light whose wavelength continuously changes. The absorbance log I ₀ / I is a 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 . Curve A indicated by a solid line is Nipponbare having an amylose content of 21.4% in Table 1 above, curve B indicated by a dashed line is Koshihikari having a content of 19.9%, and curve C indicated by a dotted line is Ishikari having a content of 23.2%. Each case is shown. From the figure, the short-wavelength region of near-infrared rays 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 that constitutes rice such as amylose, protein, and moisture. It can be easily understood that the high absorbance region is reached at the boundary of 1900 nm, and that the content of each of the above-mentioned components slightly appears as a difference in absorbance. Since the present invention elucidates this phenomenon and measures the content of a predetermined component contained in rice using the phenomenon, the wavelength of near-infrared monochromatic light irradiated on rice for measurement is as follows. , Wavelength region 1900
~ 2500 nm, a specific peak is seen on the absorbance curve for each component, for example, 1960m, 2030nm, 2100nm, 2130n
Wavelengths such as m, 2270 nm, and 2370 nm are suitable. Therefore, each of the filters 19a to 19f in which the narrow bandpass filter 19 can be seen,
In order to produce near-infrared monochromatic light of each wavelength suitable for measurement of each component constituting rice, it is required to have each wavelength as a specific wavelength transmission characteristic, that is, a main wavelength.

Next, referring to FIGS. 3, 5 and 6, details of the sample supply device including the grain size sorting device 11, the sample grinding device 12, the sample rice transport device 14, and the like will be described.

First, the configuration of the grain size sorting apparatus 11 will be described. The lower opening 26 of the supply hopper 10 is provided with a shutter 27 that is operated manually or by an electromagnetic solenoid (not shown). The upper end of the supply gutter 28 is connected to the lower opening 26, and the lower end of the supply gutter 28 is connected to the supply unit 29 of the grain size sorting device 11. Numeral 30 is a rotary sorting cylinder having a perforated wall.
Is detachably mounted on the rotating shafts 31 and 32 at both ends. The pulley 33 attached to the rotating shaft 31 and the pulley 35 attached to the electric motor 34 are connected by a belt 36, and the discharge section 37 of the rotary selection cylinder 30 is connected to the sample crusher 12 via a communication gutter 38, and the rotation selection cylinder is connected. The lower part of 30 is formed in hopper 39.

Next, the sample crusher 12 will be described in detail. A rotating shaft 54 is rotatably wrapped around a supply unit 51 at an upper part and a casing 53 having a discharging unit 52 opened at a lower part. The rotating shaft 54 has a crushing blade 55 and a stirring blade 56 having a blade portion formed at a tip end. It is planted.
The supply unit 51 and the discharge unit 52 are provided with a supply unit opening / closing lid 57 and a discharge unit opening / closing lid 58, and each of the opening / closing lids 57, 58 is biased in a direction to close the respective opening / closing lid 57, 58. Tension coil springs 59, 60, and electromagnetic solenoids 61, 62 for opening the respective opening / closing lids 57, 58 against the tension coil springs 59, 60 are provided. 63 is a variable speed motor directly connected to the rotating shaft 54,
The variable speed motor 63 is installed on a load cell scale 64, and the whole weight is measured by the crushing device. Then, the rice grain whiteness detector 43 detects the reference whiteness and activates the switching valve 50, and at the same time, the electromagnetic solenoid 61 is excited to open the supply unit opening / closing lid 57, and a fixed weight sample is put into the casing 53. Then, the switching valve 50 is switched and the supply unit opening / closing lid 57 is closed, and the variable speed motor 63 is rotated at high speed to finely pulverize the sample rice in the casing 53, and then the discharge unit opening / closing lid 58 is opened by the electromagnetic solenoid 62. A series of operations of opening and closing to discharge the sample rice into the hopper 65 is performed by the storage device 4b of the control device 4.
(ROM), and a drive circuit (not shown) for operating each of the electromagnetic solenoids and the electric motor includes a control device 4
Connected to. When measuring the sample rice without grinding it, turn on the “no grinding” button of the operation push button 7
By doing so, the variable speed motor 63 rotates at a low speed,
Even if the sample rice is a plurality of different types of rice grains, a sufficient stirring action is performed.

Next, referring also to FIG.
The sample rice (which may be stirred only without grinding) is filled into the sample container 13 in a state where absorbance can be measured, and the sample container 13 is placed in the measuring section of the near-infrared spectroscopic analyzer 3. The sample rice transport device 14 that moves to a position immediately below 23 will be described.

The sample container 13 is detachable from a guide groove 68 provided in a container holder 67 fixed to a sample container moving guide 66. A support shaft 69 having a round cross section is inserted into the hollow shaft of the sample container moving guide 66, and one side of the support shaft 69 is mounted on a turning handle 70, and the other side is supported by a bearing base 71. A rack 72 is fixedly provided in the length direction of the outer periphery of the sample container moving guide 66. The rack 72 has a pinion gear of a motor 74 mounted on a motor base 73 loosely fitted to the sample container moving guide 66. 75 mesh. The motor base 73 is connected to a fulcrum base 78 by an electromagnet 77 having a telescopic rod 76.
The fulcrum table 78 is fixed to a receiving table 79 fixed to the bottom wall of the cabinet 2. Reference numeral 80 denotes a rotating roller for compressing and filling the pulverized sample (or non-pulverized sample) on the sample container 13 and removing an excessive amount of the sample to make the surface flat. Reference numeral 81 denotes a sample container in which the measurement is completed. Injection nozzle for removing and cleaning from inside 13 with gusts,
Reference numeral 82 denotes a cleaning device that contacts and cleans the transparent glass plate 83 when the sample container 13 moves. The transparent glass plate 83 is
The crushed sample rice or the like is stretched over the measuring unit 23 so as not to enter the inside of the integrating sphere 20.

Next, a specific operation in the above embodiment will be described. First, the light source 17 is turned on by operating the operation push button 7, and the near-infrared spectroscopic analyzer is used until the near-infrared monochromatic light of a specific wavelength that reaches the measurement unit 23 based on the light emitted from the light source 17 is stabilized. Preheat the whole of 3.

While preheating the near-infrared spectroscopic analyzer 3, sample rice (brown rice or white rice) is put into the supply hopper 10, and the operation of the operation push button 7 causes the electric motor 74 to rotate, so that the sample container 13 is placed in the sample crusher. The hopper 65 is moved to a predetermined position immediately below the hopper 65 provided below. When the movement of the sample container 13 to the predetermined position is completed and the operation of the electric motor 74 is stopped, the shutter 27 is opened manually or by an electromagnetic solenoid (not shown), and the sample rice in the supply hopper 10 is moved through the lower opening 26. To release through.

When the shutter 27 is opened, the electric motor 33 is started by an appropriate limit switch (not shown) or the like operated by the shutter 27, and the grain sorting device 11 is driven. The sample rice flows down the supply gutter 28 from the supply hopper 10 and the lower opening 26 and is sent to the supply section 29. The sample rice in the sorting cylinder 30 is sent to the discharge unit 37 side while flowing in a layered manner by the rotation of the rotary sorting cylinder 30. Meanwhile, the fine grains fall through the perforated wall surface of the rotary sorting cylinder 30 and fall into the hopper 39, and the sized sample rice remaining in the rotary sorting cylinder 30 is sampled from the discharge unit 37 via the connecting gutter 38. It is put into the casing 53 of the crushing device 12. When the sample rice accumulates in the casing 53 to a certain extent and the load cell scale 64 senses a predetermined weight, the switching valve 50 is operated and the communication gutter 38 is operated.
And the electromagnetic solenoid 61 is demagnetized to close the supply unit opening / closing lid 57. When the supply unit opening / closing lid 57 closes, the variable speed motor 63 rotates at high speed, and the sample rice in the casing 53 is finely pulverized by the pulverizing blades 55. When the sample rice particles are ground to about 50 microns required for the measurement of absorbance, a variable speed motor 63 is activated by a timer or the like (not shown).
Is stopped, and at the same time, the discharge portion opening / closing lid 58 is opened by the electromagnetic solenoid 62 to discharge the powdered sample rice into the hopper 65. At this time, the sample rice spilling out of the hopper 65 and the sample rice spilling when putting the rice grains into the casing 53 from the connecting gutter 38 fall into the receiving box 15 installed below. In addition,
In the present embodiment, the case where the sample rice is pulverized was described, but in the case of no pulverization, the variable speed motor 63 is rotated at a low speed, and the sample rice is stirred by the stirring blade 56, and then the hopper 65 is rotated.
Release into. Thus, when a plurality of rice are mixed and measured at the same time, the sample rice is sufficiently stirred to reduce measurement errors.

The finely powdered sample rice thus obtained is received in the sample container 13 located immediately below the hopper 65, and the excess amount of the sample rice that has exceeded the amount received and rises on the container 13 is received in the receiving box 15.
To fall. Next, by operating the operation push button 7 or automatically restarting the electric motor 74, the sample container 13 containing the sample rice is removed from the measuring unit 23 of the near-infrared spectroscopic analyzer 3.
The operation proceeds to the operation of transporting the sheet to a predetermined position immediately below. In this transport process, the sample rice in the state of being raised in the sample container 1 is compressed and filled by the rotating roller 80, and the excess sample is removed to the receiving box 15 and the surface of the sample rice is shaped into a flat surface. You. When the sample container 13 is placed at a predetermined position, the motor 74 automatically stops its operation. Thus, measurement preparation is completed. In the present embodiment, the sample rice charged from the supply hopper 10 is filled in the sample container 13,
Sample rice transporter 14 that transports sample rice to measuring unit 23
Is described, but the sample container mounting box 5 is detachably provided directly below the measuring unit 23, the mounting box is pulled out from the cabinet 2, and after the sample container filled with the crushed sample is placed, It is a matter of course that the sample container mounting box may be inserted into the cabinet 2 so as to supply the sample rice.

Once the metric work is completed, then first 1960nm
Is a light source 17 and a reflecting mirror 18
(See FIG. 2), and the process of measuring the reflection absorbance when the sample rice 24 is irradiated with near-infrared monochromatic light having a wavelength of 1960 nm. The measurement operation of the reflection absorbance is performed by measuring the total irradiation light amount irradiated to the sample rice 24, that is, the reference irradiation light amount, and when the sample rice 24 is irradiated with the reference irradiation light amount, the light is actually reflected by the sample rice 24. And the measurement of the amount of reflected light. Either of these two measurements may be performed first for one filter, but it is assumed that the measurement of the reference irradiation light amount is performed first. The measurement of the reference irradiation light amount is performed by turning the inclination angle of the reflecting mirror 18 having a variable inclination angle to an angle such that the reflected light directly hits the inner wall of the integrating sphere 20 by using a rotating means using a motor or the like. (Not shown). In this way, the light from the reflecting mirror 18 directly applied to the inner wall of the integrating sphere 20 finally reaches the detectors 21a and 21b while diffusing and reflecting the inner wall in multiple directions, and is detected as the reference irradiation light amount. Is done. On the other hand, the measurement of the amount of reflected light from the sample rice 24 is performed according to the above-described principle after the inclination angle of the reflecting mirror 18 is returned to the original position shown in FIG. In addition,
The selection of the first filter after the completion of the measurement reference, 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,
Needless to say, it can be automatically performed according to the program. Further, it is also useful to increase the measurement accuracy by performing each of the above-described measurement of the reference irradiation light amount and the reflected light amount for one filter a plurality of times, and taking an average of the measured values. Detectors 21a, 21
The respective measurement values based on the reference irradiation light amount detected by b and the reflected light amount from the sample rice 24 are used as actual measurement data for calculating the respective content rates of components constituting rice, for example, protein, amylose, and moisture, by the control device 4. Contacted to storage device 4b
Is temporarily stored in a writable memory (hereinafter referred to as RAM).

When the measurement of the absorbance at the irradiation wavelength of 1960 nm is completed,
The process shifts to the measurement of the absorbance at the next irradiation wavelength, that is, at 2030 nm in this embodiment. Here, the measurement of the reference irradiation light amount is performed by the same method and procedure as in the case of 1960 nm described above. Each measurement value is communicated to the control device 4 as actual measurement data for calculating the content of each component as in the previous case, and is temporarily stored in the RAM in the storage device 4b. Hereinafter, similarly, each absorbance measurement at each of the remaining irradiation wavelengths, that is, wavelengths 2100 nm, 2130 nm, 2270 n
The absorbance measurement at m, 2370 nm is sequentially performed, and each measured value is communicated to the control device 4 as actual measurement data and stored in the RAM.

Note that, after the absorbance measurement at a specific wavelength is completed, the exchange / selection operation of each of the filters 19a to 19f of the narrow band-pass filter 19 accompanying the shift to the absorbance measurement at the next specific wavelength is normally performed by the memory of the control device 4. The measurement is automatically performed according to a procedure program previously written in the ROM in the device 4b. However, in the case of the present embodiment, the absorbance measurement does not necessarily have to be performed for all of the six wavelengths, and the measurement is performed. The wavelength can be arbitrarily selected in consideration of the accuracy required for the required quality evaluation value or the time required for the measurement, and the selection can be made with the measurement wavelength selection button in the operation push button 7. it can.

The measurement of the absorbance described so far is performed simply by sequentially replacing the six filters 19a to 19f set in the narrow band pass filter 19, thereby measuring the spot-like absorbance at each main wavelength of each of the filters 19a to 19f. Method, but based on the angle of incidence of the incident light on the surface of the filter.
°, the maximum transmission wavelength is several tens of nm from the main wavelength.
Utilizing the phenomenon of shifting within the range, the absorbance can be continuously measured in a wavelength region of 1900 to 2500 nm in which the difference in the component content is conspicuous in the absorbance difference. In the case of the first embodiment (see FIG. 2), the angle of the optical axis incident on the narrow band-pass filter 19 formed in a disk shape is adjusted by an appropriate adjusting means (such as a motor) based on a command signal from the control device 4 (see FIG. 2). This is possible by a gradual and continuous change (not shown).

Next, the arithmetic unit 4c of the control device 4
Numerous measured data obtained by the absorbance measurement stored in the storage device, that is, the measured values of the reference irradiation light amount and the reflected light amount at each measurement wavelength, and for calculating the content ratio of each component stored in the ROM of the storage device 4 in advance. Based on the component conversion coefficient value of
Amylose, an important ingredient in evaluating rice quality,
Calculate the protein and water content. The component conversion coefficient value previously written in the ROM of the storage device 4 for each component is determined based on the content of each component measured using, for example, a chemical quantitative analysis method for a large number of sample rices. Is a constant obtained by performing signal processing on the absorbance measurement value from the above and performing multiple regression analysis. Next, the arithmetic unit 4c first calculates the quality-related value K based on the respective contents of amylose, protein, and water determined as described above, using the following equation (1).

K = (Amylose content) × (Protein content) × ｛15+
15− (moisture content)｝ (1) In the above formula (1), A, B, and C represent R of the storage device 4b.
Pre-stored in the OM or when measuring the sample,
A = 1.0, B = 0.3, and C = 0.75 are suitable for evaluating the quality of Japanese rice, which is a specific coefficient for calculating the quality evaluation value input to the control device 4 via the input device 9. ,
Since these standard coefficients may have different standard preferences depending on the region or country where the rice is eaten, different numerical values may be more suitable.

The arithmetic unit 4c further calculates the rice quality evaluation value T by the following equation (2) based on the quality-related value K obtained by the above equation (1). The higher the quality evaluation value T, the better the taste or quality.

T = 50000 / K ² (2) The quality evaluation value T calculated according to the above equations (1) and (2), and the amylose, protein, The content of each component such as moisture is visually displayed on the display device 6 at the same time when the calculation is completed in the arithmetic unit 4c, and is calculated from the printer 8 automatically or based on a command to the operation push button 7. A hard copy of the value is delivered. As for the amylose content, the content ratio of amylopectin and amylopectin, which constitute the starch together, is more important than the amylose content itself, so that it is preferable to display the content ratio instead of the content ratio.

When all the absorbance measurements of the sample rice have been completed, the motor 74 is started, and the sample container 13 is moved to a predetermined position below the hopper 65 for discharging the sample rice after the measurement. At that time, the cleaner 82 comes into contact with the transparent glass plate 83 and slides on the surface to remove the attached matter. Next, by operating the electromagnet 77, the sample container moving guide 66 is rotated by 90 °, and the sample rice in the sample container 13 is discharged toward the receiving box 15 located below. At the same time, the injection nozzle 81 is operated, and the inside of the sample container 13 is cleaned by the high-pressure air coming out thereof in preparation for the next measurement. Further, if necessary, a jet nozzle may be provided in the rice milling device 11 and the crushing device 12 in some cases. The case where the sample container 13 automatically reciprocates by the operation of the electric motor 74 has been described.
Manual operation by pushing and pulling 70 can be performed, and discharge of sample rice from the sample container 13 can be performed by appropriately rotating the handle 70 for rotation. Further, in order to arrange the sample prepared outside from the sample supply device alone in the measuring section 23 of the near-infrared spectroscopic analyzer 3, the sample container 13 is once moved by pressing the turning handle 70. After being moved to the lower part, the sample container 13 is pulled out from the external supply unit 16, filled with sample rice, and inserted into the guide groove 68 of the container holder 70.

The above-mentioned quality evaluation device measures the absorbance when irradiating the sample rice with near-infrared monochromatic light of a specific wavelength by measuring the intensity of the reflected light from the sample rice. Although the apparatus was used, as shown in FIG. 3, the bottom surface of the sample container 13 was formed of a transparent glass plate 13a, and a detector 21c was disposed below the measuring unit 23 to transmit the sample rice. A transmission type near-infrared spectrometer that measures the intensity of light can also be used, and more precise near-infrared spectroscopy that measures absorbance based on both reflected light and transmitted light An apparatus can also be used.

In the above description, among the amylose and amylopectin constituting starch, it was stated that the quality evaluation value of rice was obtained based on the analysis of amylose, but the content of amylopectin was measured in place of amylose, and the specific coefficient of amylopectin was determined. Similar results can be obtained by setting the equation (1).

Further, in addition to the main components of starch (amylose or amylopectin), protein, and water described above, the content of other components such as fat is measured, and the specific coefficient for fat is expressed by formula (1). By setting, a more accurate quality evaluation value can be obtained.

Next, the relationship between the mesh width of the rotary sorting cylinder 30 of the grain size sorting apparatus 11 and the taste value will be described based on Table 2. Koshihikari A ₁
AA ₃ and Nakasei Shinsenhon A ₁ AA ₃ are obtained by sorting the same sample rice by changing the mesh width of the rotary sorting cylinder 30.

As can be seen from Table 2 above, even for the same sample rice, the taste value changes by changing the eye width. That is, when the mesh width is increased, the particle size of the sampled rice to be sorted is increased, and the protein content and the amylose content are reduced, thereby improving the taste value. Therefore, when analyzing the sample rice with a rice quality evaluation device, it is necessary to adjust the particle size of each sample, and even if samples having different particle sizes are compared, accurate comparison of taste values is not achieved.

〔The invention's effect〕

As described in detail above, according to the rice quality evaluation method and the rice apparatus according to the present invention, sensory tests based on tastes with individual differences, or time-consuming, without the need for methods such as chemical quantitative analysis requiring skill, Anyone can easily and accurately obtain an accurate rice quality evaluation value in a short time. In particular, since the component content of rice varies greatly depending on the size of the sample rice, the particle size of the sample rice must be reduced. By measuring at a constant,
When comparing the quality of various rice, the accuracy of the quality evaluation value can be ensured.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of an apparatus and a working method used in the present invention, FIG. 2 is a schematic cross-sectional view of main parts of the near-infrared spectrometer of FIG. 1, and FIG. Fig. 4 is a graph (absorbance curve) showing the relationship between near-infrared irradiation wavelength and absorbance for rice of different brands, Fig. 5 is a side view of the crusher, and Fig. 6 is a view of the sample transporter. It is a part perspective view. In the figure, 1 ... rice quality evaluation device, 2 ... cabinet, 3 ...
Near-infrared spectrometer, 4 ... control unit, 4a ... input / output signal processing device, 4b ... storage device (ROM, RAM), 4c ... arithmetic unit, 5
... Sample container mounting box, 6 ... Display device, 7 ... Operation push button, 8 ... Printer, 9 ... Input device, 10 ... Supply hopper, 11 ... Grain size sorting device, 12 ... Sample crusher, 13 ... Sample container, 14 ... sample rice transporter, 15 ... reception box, 16 ... external supply unit, 17 ... light source, 18 ... reflector, 91 ... narrow band pass filter, 20 ... integrating sphere, 21a, 21b, 21c ... detector, 22 ... Daylighting window, 2
3 ... measurement unit, 24 ... sample rice, 25 ... motor, 26 ... lower opening, 27 ... shutter, 28 ... supply gutter, 29 ... supply unit, 30 ... rotation sorting cylinder, 31 ... rotation axis, 32 ... rotation axis, 33 ... Pulley, 34
... Electric motor, 35 ... Pulley, 36 ... Belt, 37 ... Ejector, 38
... Connecting gutter, 39 ... Hopper, 50 ... Switching valve, 51 ... Supply unit, 52
... discharge unit, 53 ... casing, 54 ... rotary shaft, 55 ... crushing wing,
56 ... stirring blade, 57 ... supply part opening / closing lid, 57 ... discharge part opening / closing lid, 5
9,60… Tension coil spring, 61,62… Electromagnetic solenoid, 63
... variable speed motor, 64 ... load cell scale, 65 ... hopper, 66
… Sample container moving guide, 67… Container holder, 68… Guide groove, 69… Support shaft, 70… Rotating handle, 71… Bearing stand, 72
... Rack, 73 ... Motor stand, 74 ... Electric motor, 75 ... Pinion gear, 76 ... Telescopic rod, 77 ... Electromagnet, 78 ... Support point stand, 79 ...
Cradle, 80: rotating roller, 81: spray nozzle, 82: cleaning device, 83: transparent glass plate, 84: electric motor.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01N 21/00-21/01 G01N 21/17-21/61

Claims (4)

(57) [Claims] An absorbance of a sample rice is measured by a near-infrared spectrophotometer which measures the content of a component affecting the taste of rice as an absorbance difference, and the rice is analyzed by the absorbance and a predetermined component conversion coefficient. Calculate the content of the specified component contained in,
A rice quality evaluation method for evaluating the quality of a sample rice based on the component content, wherein a non-milled sample rice is sorted to a certain particle size, and then crushed to obtain a crushed sample rice, A method for evaluating the quality of rice, comprising measuring the absorbance of the ground rice sample using a near-infrared spectrometer and calculating the content of a predetermined component. 2. The rice quality evaluation method according to claim 1, wherein the quality evaluation value of the sample rice is calculated based on a predetermined component content and a predetermined specific coefficient. 3. A near-infrared spectrometer for irradiating a sample rice with near-infrared rays and measuring the content of components affecting the taste of rice as a difference in absorbance, and a near-infrared spectrometer. A sample rice supply device for supplying sample rice, a control device for processing and calculating signals of the near-infrared spectrometer and controlling each device, and a display device for visually displaying the calculation result of the control device A rice quality evaluation device, comprising: a grain size sorting device with respect to the sample rice supply device; and a sample grinding device between the grain size sorting device and the sample supply device; The rice quality evaluation device characterized in that the sample rice having a uniform grain size adjusted by sorting the sample rice with the grain size sorting device is pulverized and supplied to the sample rice supply device. 4. The rice quality evaluation device according to claim 3, wherein the sample crusher is switchable between a high-speed operation for crushing and a low-speed operation for stirring.