JPH0612331B2 - Method and apparatus for measuring taste of rice - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a method and an apparatus for measuring the eating quality of rice by an optical method.

<Prior Art> Several types of rice taste measuring devices (taste meters) have been proposed in the past. The taste measurement method using these devices is based on the analysis of the ingredients contained in rice. However, the correlation system between the taste of rice and the contained ingredients has not yet been sufficiently elucidated, and there is no definite standard for which ingredient should be analyzed. For this reason, in the conventional device, the taste is judged by various originally developed analysis methods, but the credibility of the judgment result is not yet sufficient, and in practice, it has not reached a satisfactory level. Is the current situation.

For this reason, such a device is rarely used for actual taste determination, and in reality, most of the time, the taste is determined by actually cooking rice and actually eating it. In addition, in some cases, taste is judged by visually inspecting the gloss after cooking rice.

<Problems to be Solved by the Invention> As described above, a satisfactory determination result has not been obtained by a conventional taste analyzer using a component analysis method, but this is due to the complexity of the taste of rice. it is conceivable that. For example,
For fruits, etc., it is possible to judge the taste relatively easily based on the sugar content, but in the case of rice, there are no standards for taste, so this component analysis method does not give good results. . Rather, in the case of the taste of rice, the mouthfeel of rice occupies a very large weight. The research conducted by the present inventor has revealed that the greatest factor that determines the quality of the mouthfeel is the surface water retention characteristic of each rice grain. That is, after rice is cooked, a water-retaining film is formed on the surface of the rice, and the thickness of this water-retaining film affects the feeling when eating rice. The thicker the water-retaining film, the better the texture. It means that it tastes good. The reason is that the water retaining film is composed of alpha-starch containing a large amount of water and other substances, and this acts to give a smooth feeling in the mouth. Since this smoothness feels like delicious rice, the deliciousness of the rice depends on whether or not the water retaining film is thickly formed on the surface of the rice grains. However, conventionally, a means for measuring the film thickness of such a water retaining film has not been developed, and there is no idea to measure the water retaining film.

In addition, conventionally, the taste of rice is judged based on the luster of rice after cooking, and this method has been evaluated as having certain credibility. However, this gloss determination is entirely visual, requires considerable skill before the determination can be made, and has the disadvantage that it is poor in objectivity due to individual differences.

By the way, the relationship between such luster and taste of rice will be examined in detail. First, it is considered that the gloss associated with the taste is not a widespread light reflected from the surface of the rice but a kind of reflected light. That is, the luster is the reflected light emitted from the water retaining film that covers the surface of the rice grain. There are fine irregularities on the surface of rice grains. Therefore, if the light directly hits this, it will be diffusely reflected. However, if the surface of the rice grain is sufficiently covered with a thick water-retaining film containing water (though it is still considered to be several microns), the irregularities are filled and the surface becomes mirror-like, resulting in no irregular reflection of light. , Will be a specular reflection. Also, when the water retention film is thin, all the irregularities on the rice grain surface are not filled, and the protrusions protrude from the water retention film, which means that light is diffusely reflected at this portion, and the specular reflection reflects the concave portion. Only the part of the filled water retaining film is left, and as a result, the light amount of specular reflection is reduced as compared with the thick water retaining film.

As described above, the thickness of the water retention film is proportional to the amount of specular reflection light. Therefore, by measuring the amount of specularly reflected light, the thickness of the water retention film can be known, and by extension, the eating quality of the rice can be determined. Then, the inventor has realized that the method using the polarization filter is an excellent means for capturing only the specularly reflected light.

In view of the above points, the present invention provides a method and an apparatus for accurately and objectively measuring the taste of rice by performing gloss determination using polarized light.

<Means for Solving the Problem> The technical means of the method for measuring the taste of rice according to the present invention is to irradiate a rice to be measured to be reflected with a light beam, and to interpose a polarizing filter in the optical path of the light beam. Then, it is to find the degree of eating from the light quantity value of the reflected light.

Furthermore, as the rice to be measured, normally cooked cooked rice can be used, and it is also watered / heated based on certain conditions, but it is not perfect rice but it is sufficient for judgment. It is also possible to use the rice-like denatured one.

Further, the eating degree can be obtained from the difference between the maximum value and the minimum value of the amount of received light by changing the angle of the polarization filter or attaching / detaching the polarization filter.

Technical means of the eating quality measuring device of the present invention, a light source that irradiates the rice to be measured rice with a light beam, a device that receives the reflected light from the rice rice and measures the amount of light, and the optical path of the light beam. It is composed of an intervening polarization filter.

It is also possible to obtain a more accurate measurement result by measuring from different directions using a rotatable sample table on which the rice to be measured is placed and obtaining the average value. It is possible.

Further, it is possible to rotatably install the polarizing filter or to provide a convex lens for condensing on the back surface of the polarizing filter.

<Operation> In the method for measuring the degree of taste of the present invention, the target rice to be measured needs to be polished rice. Brown rice must be polished first. Further, for measurement, it is necessary to add rice to the rice by adding water and heating. In addition to cooked rice such as cooked rice,
It includes so-called raw-boiled rice that has not been cooked to the core. In other words, it is sufficient if the rice is cooked to the extent necessary and sufficient for the measurement. In the present invention, the degree of taste is optically measured, and since only the surface layer of the rice grain is needed, it is sufficient that the surface layer of the rice to be measured has definitely changed into a rice shape.
It is not necessary to cook rice inside the rice grain.

The taste of rice varies depending on how it is cooked. Even if the same rice is cooked well, good cooked rice is good, and poor cooked rice is not good. This also applies to the taste measurement by the optical method of the present invention. Therefore, when obtaining the original taste of rice or comparing it with other rice, it is necessary to match the conditions for rice formation. If the processing conditions for making rice, that is, the conditions for adding water and heating are carried out under a fixed condition, the measurement results will be universal and very useful in practice.

The to-be-measured rice that has been cooked into rice is placed in an appropriate dish-shaped container in order to put it on the measuring device. Alternatively, in order to omit the arranging work, put the polished rice in a container with a predetermined lid, soak it in hot water for suspecting, add water and heat to make rice, and only the lid at the time of measurement It is also possible to remove it and put it on the measuring device as it is. However, in either case, the surface of the rice to be measured in the container should be almost flat in order to make the light reflection angles uniform.

In this way, the measurement is carried out, but when pearled rice is made into rice by adding water and heating, the surface of each rice grain is a large amount of water containing alpha starch, and other substances It is in a state of being covered with the configured water retention film. And this water retention film is a substantially transparent body. Therefore, when this rice-shaped rice is irradiated with a light beam, a part of the light is reflected by the surface of the water retaining film as polarized light in a direction parallel to the projection surface. Further, the remaining irradiation light becomes refracted light and enters the transparent water retaining film, and is reflected by hitting the bottom surface of the water retaining film layer, that is, the skin surface of the rice rice under the water retaining film. However, since the rice-like rice has a finely uneven skin surface, this refracted light is scattered and reflected in irregular directions. Also, this reflected light is not polarized. Therefore, the reflected light of rice-shaped rice is a polymerization light of the polarized light reflected on the surface of the water retaining film and the non-polarized light transmitted through the water retaining film layer and diffusely reflected on the rice skin.

This total reflected light is as follows when it passes through the polarization filter. First, since the reflected light from the surface of the water retention film is polarized light, it passes through the filter when the polarization direction and the optical axis direction of the polarization filter are parallel to each other, and is blocked by the filter when they are orthogonal to each other. . On the other hand, since the diffusely reflected light from the rice skin surface is non-polarized light, it always passes through the filter with a constant transmittance regardless of the direction of the optical axis of the polarizing filter. Therefore, in order to change the direction of the optical axis of the polarization filter, rotate the polarization filter and obtain the difference between the maximum value (value when the polarized light passes) and the minimum value (value when the polarized light is blocked) of this passing light amount. , The amount of light reflected on the surface of the water retention film can be known. This amount of light is the amount (thickness) of the water retention film, and the larger the amount, the better the mouthfeel and the better the taste. The taste may be displayed directly by the value of the amount of reflected light on the surface of the water retaining film, but it is also possible to clarify the display of the taste by applying a constant correction coefficient to the value. .

Further, the installation position of the polarization filter can be set to the incident path instead of the reflected light path. In this case, the reflected light is directly measured without passing through the filter.

Furthermore, instead of using a rotatable polarization filter, 2
A switching method can also be used by using a single filter.

In addition, the difference in the light amount may be the difference between the light amount value when the polarization filter is used (preferably set to the minimum value) and the light amount value when the polarization filter is removed.

Further, in the case of using the convex lens and the light receiving element, the light passing through the polarization filter is focused by the convex lens and is received by the light receiving element provided at the converging point, and the light quantity is converted into an electric quantity.

<Example> An example of the eating quality measuring device of the present invention will be described with reference to the drawings. FIG. 1 shows the first embodiment. Reference numeral 1 denotes a sample table, on which a rice-shaped rice A having a flat surface is placed in a container 2. The rice-shaped rice A is prepared by subjecting the sample rice to watering and changing heat under separate conditions in a predetermined pot and a pot (not shown). The sample table 1 is rotatable, and at the time of measurement, the sample table 1 is rotated by an appropriate angle (10 ° to 60 °) and the taste is measured at each angle, so that the direction error of the sample is eliminated. It can be prevented. 3 is a light source. The type of light source is free when measuring in the form of external light shielding, but when measuring in natural light, a specific wavelength such as a sodium lamp is used to facilitate separation from natural light. It is better to use a light source with Further, since the light source 3 is a surface light source, a large number of small lamps are arranged and the diffuser plate 4 is used to planarize the light quantity. The light emitted from the light source 3 hits the rice rice A, which is a sample, and is reflected. At the time of reflection, a part thereof becomes polarized light as described above, but the amount of polarized light changes depending on the incident angle. Therefore, the incident angle is set to an angle (polarization angle) that maximizes the polarization. In the case of rice rice, it is preferable to set it at 50 ° to 70 °.

The polarization filter 5 is provided so as to be orthogonal to the traveling direction of the reflected light from the sample. This polarizing filter is rotatable and can be freely rotated by the motor 6. 7
Is a convex lens that focuses the light that has passed through the polarization filter 5. A light receiving element 8 is provided at the light focusing position. Reference numeral 9 denotes a display position, which digitizes and displays the amount of light detected by the light receiving element 8.

Next, the operation of the device will be described. The light emitted from the light source 3 is surface-averaged by passing through the diffusion plate 4, and becomes a surface light source having no positional strength and enters the surface of the rice rice A. This light hits rice and is reflected,
Of these, the light reflected on the surface of the water retaining film becomes polarized, while the light that passes through the water retaining film and hits the rice skin to be diffusely reflected becomes unpolarized. Then, these overlapping reflected lights pass through the polarization filter 5. At this time, in the polarization filter 5, of the components of the incoming light, only the component of the optical axis parallel to the optical axis of the filter 5 is passed, and the orthogonal component is blocked. Therefore,
By rotating the filter 5 and changing the angle of the optical axis, the component of the passing light (or the blocking light) can be controlled. That is, in the present case, if the optical axis angle of the polarization filter 5 is made parallel to the optical axis angle of the reflected polarized light, the polarized component in the reflected light will pass through the filter 5 as it is, and conversely When the angle is made orthogonal to the optical axis angle of the reflected polarized light, all the polarized components in the reflected light are blocked. Therefore, the amount of the polarization component in the reflected light can be known by rotating the filter by 90 ° from the reflected polarized light passing position to the blocking position and taking the difference in the amount of passing light at both positions. The light passing through the filter 5 is focused by the lens 7 and reaches the light receiving element 8, where the light amount is measured. The signal from the light receiving element 8 is sent to the display device 9 and digitized and displayed. In addition, even if the sample rice-shaped rice is laid out carefully so that it becomes flat, unevenness etc. will inevitably occur on the surface,
Since there is unevenness in the reflection, the sample table 1 can be moved to 10 ° or 6 °, for example.
Rotate by 0 °, measure at each position, and take the average. The highest value may be taken instead of the average value.

Measurement test example (1): Target rice: Koshihikari (Mie prefecture, produced in 1987) Sasanishiki (Miyagi prefecture, produced in 1987) Standard price Rice condition: rice amount 20g, added water amount 20g, heating time 15 minutes, heating temperature Conditions at the time of 100 ° C. measurement: The above-mentioned three types of rice to be measured were watered and heated under the above-mentioned conditions and then measured.

Display of measured value: The measured value is represented by the voltage (V) from the light receiving element.

The upper values in the table are for when the polarized component passes, and the lower values are for when the polarized component is blocked by rotating the filter by 90 °. In addition, the measured values are shown as an average of the values from 6 directions in which the sample stage is rotated by 60 °.

From the above measurement test results, it was found that it is possible to measure the difference in the degree of taste between rice types. In addition, the results of the taste test actually tried were that Koshihikari had the best taste, followed by Sasanishiki, and the standard price rice had the lowest taste, which was in agreement with the above measurement results.

Measurement Test Example (2): Sasanishiki was measured every 20 minutes after 30 minutes had elapsed after cooking rice. The measurement method is the same as in Test Example (1).

From the above measurement test results, it was found that it is possible to clearly measure that the taste deteriorates with the lapse of time after cooking rice. In addition, even when actually eating, it was confirmed that the eating quality was deteriorated with time.

As can be seen from the results of Test Examples (1) and (2), according to the present invention, it is possible to numerically and clearly measure the taste of rice or rice. Therefore, for example, by standardizing the measuring method, it becomes possible to objectively display the degree of taste of various rice, that is, the superiority or inferiority of the taste, and to simplify the classification of rice.

A second embodiment is shown in FIGS. 1
Reference numeral 1 is a container for containing the measured rice. 12 is the body,
It has a short cylindrical shape with an inner diameter of 60 mm and a height of 8 mm. Reference numeral 13 denotes upper and lower lids, which are applied to both upper and lower surfaces of the body 12. The lid 13 is formed with small holes 14 having a diameter of about 2 mm, one for each about 2 cm ² . The lids 13 applied to the upper and lower surfaces of the body 12 are held by the assembly fixture 15.
The small holes 14 may be formed in the body 12.

Next, a method of using the container 11 will be described. 12 g of rice to be measured is put in the container 11 and the lid 13 is attached. Then soak it in boiling water for 15 minutes and then in cold water for 2 minutes to cool. At this point, the rice to be measured in the container 11 has become rice-like and expands to fill the space in the container 11 tightly. Next, the upper and lower lids 13 are removed. Since the measured rice has expanded, even if the lid 13 is removed, it does not fall off the body 12. Also, the lid 13
The surface of the removed rice-shaped rice is a smooth surface. Therefore, the tasting degree of this is measured using the same measuring device as in the first embodiment. However, unlike the first embodiment, the sample table of this device can be turned over with the container 11 loaded. Therefore, both the upper surface and the lower surface of the sample can be measured.

In the above-mentioned second embodiment, the measurement area is wide and the error is small, and it is not necessary to transfer the sample rice to the container. In addition, since the content area of the container is fixed and the water absorption of rice is regulated, if the rice to be measured is first weighed and put in the container 11, it is not necessary to measure the amount of water added and it is always constant. It is convenient because it can make rice-shaped rice.

Incidentally, in the present invention, it is possible to adopt configurations other than the above-mentioned embodiment. For example, a polarization filter may be provided in the incident light path, or a plurality of polarization filters may be provided for switching, or the difference between the minimum light amount value with the polarization filter and the light amount value without filter may be determined. You can freely make changes such as determining the degree of palatability.

<Effects of the Invention> In the method for measuring the texture of rice of the present invention, the taste of rice is measured by using the reflected polarized light when the rice to be measured is irradiated with light, and the light quantity of the reflected polarized light is used. It is possible to numerically and objectively measure the eating quality of.

According to the second aspect, since the taste of cooked rice can be measured, it is possible to measure the taste of rice itself as well as the taste of rice itself.

According to the third aspect of the present invention, by making the cooking process uniform, it is possible to make the measurement results universal and to efficiently perform the cooking process in a short time.

According to the fourth aspect, since the polarization filter is provided in the optical path of the reflected light, the measurement can be performed more accurately.

According to the fifth aspect, the polarization filter is rotated, and the eating quality is obtained from the difference in the amount of received light, which facilitates the measurement work.

According to the sixth aspect of the present invention, the measurement is simplified because the difference in the amount of light received when the polarization filter is attached and detached.

According to the seventh aspect of the present invention, since the rice-forming process is performed in a predetermined container, the rice-forming process is simple, and the arranging work at the time of measurement is not required, and the work efficiency can be improved.

The eating quality measuring device of the present invention requires a small number of parts, can be manufactured inexpensively, is easy to handle, and can accurately measure the taste.

According to claim 9, by rotating the sample table,
Since measurement can be performed from each direction, the accuracy of measurement can be improved.

According to the tenth aspect, since the polarization filter is rotatable, the operation at the time of measurement is easy.

According to the eleventh aspect, highly accurate and efficient taste measurement can be performed with a relatively simple structure.

[Brief description of drawings]

The drawings show an embodiment of a rice taste measuring device of the present invention, FIG. 1 is a diagram showing an outline of the first embodiment, FIG. 2 is an exploded perspective view of a container 11 used in the second embodiment, and FIG. The drawing is a cross-sectional view of the container 11 in an assembled state. 1 ... Sample stage, 2 ... Container, 3 ... Light source, 4 ... Diffusion plate, 5 ... Polarizing filter, 6 ... Motor, 7 ... Convex lens, 8 ... Light receiving element, 9 ... Display device, 11 ... Container.

Claims (11)

[Claims] 1. A measurement of the eating quality of rice, which comprises irradiating a light beam on rice to be measured and reflecting it, and interposing a polarizing filter in the optical path of the light beam to determine the eating quality from the light quantity value of the reflected light. Method. 2. The method for measuring the taste of rice according to claim 1, wherein cooked rice is used as the rice to be measured. 3. The taste of rice according to claim 1, wherein the rice to be measured is rice in which at least the surface layer portion of the rice grains has been cooked by adding water and heating under certain conditions. Degree measuring method. 4. The method for measuring the taste of rice according to claim 1, wherein a polarizing filter is interposed in the optical path of the reflected light from the rice to be measured. 5. The method for measuring the taste of rice according to claim 1, wherein the angle of the polarizing filter is changed to obtain the taste from the difference between the maximum value and the minimum value of the amount of received light. 6. The method for measuring the taste of rice according to claim 1, wherein the taste is determined from the difference in the amount of received light between when the polarizing filter is interposed and when the polarizing filter is not used. 7. The polished rice is placed in a container, and the whole container is soaked in boiling water to add water and heat, and then at least one side of the container is opened to measure the rice grains exposed there. The method for measuring the degree of eating quality of rice according to claim 3. 8. A light source for irradiating a rice-shaped rice to be measured with a light beam, a device for measuring the amount of light reflected from the rice to be measured, and a polarizing filter interposed in the optical path of the light beam. Rice taste measuring device. 9. The palatability measuring device according to claim 8, wherein a rotatable sample stage is used and the rice to be measured is placed on the sample stage. 10. The rice taste measuring device according to claim 8, wherein a polarizing filter is rotatably installed. 11. The measurement of the eating quality of rice according to claim 8, wherein a polarizing filter is installed in the optical path reflected from the rice to be measured, a convex lens is provided on the back side of this polarizing filter, and a light receiving element is provided at the light beam focusing position. apparatus.