JP2016105074A - Moisture state determination method of rice to be cooked, immersion time determination method and rice cooking facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and surely evaluate a moisture state of rice to be immersed to water, and preferably control texture of rice after being cooked.SOLUTION: The rice to be cooked which is disposed in a state of being immersed to water, is optically monitored, for measuring moisture content-related information which relates to a moisture content of the rice to be cooked, chronologically, then, a saturation state of the moisture content of the rice to be cooked which is estimated based on the moisture content-related information is detected, for determining that the rice to be cooked is in a moisture state suitable for rice cooking.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a water content determination method, a soaking time determination device, and a rice cooking facility for rice to be cooked.

  In recent years, methods for evaluating the taste of cooked rice have been studied, and techniques for deliciously cooking rice have been studied (see, for example, JP-A-2002-323418 (Patent Document 1) and the like). In general, the typical factors that influence the taste of rice are the texture of cooked rice, the texture of cooked rice, etc., but the hardness of cooked rice and the stickiness of cooked rice are directly measured and cooked. Since it is difficult to control the rising state, it is conceivable to control the texture after cooking by measuring the state of rice before cooking. Also, the texture of cooked rice varies greatly depending on the rice cooking method, and the quality of cooked rice is greatly affected by controlling the steps of washing, dipping, and cooking (heating) rice. Here, the process of immersing rice in water before cooking rice is a particularly important process in controlling the texture of cooked rice after cooking.

  It is known that the water content of rice varies greatly depending on the dipping conditions (time, temperature, concentration, etc.) during the dipping process. Generally, the moisture content of rice is evaluated by a method of measuring a sample after immersion with a moisture meter.

  In addition, an attempt has been made to evaluate the internal structure of cooked rice by MRI (nuclear magnetic resonance microimaging) as a factor affecting the water content (for example, JP 2000-065768 (Patent Document 2), Mitsuru Yoshida, " Observation of Moisture Distribution Affecting Texture of Food by MRI ", Nippon Shokuhin Kagaku Kogaku Kaishi Vol. 59, No. 9, 478-483 (2012) (Non-patent Document 1) etc.).

JP 2002-323418 A JP 2000-065768 A

Mitsuru Yoshida, "Observation of Moisture Distribution Affecting Texture of Food by MRI", Nippon Shokuhin Kagaku Kogaku Kaishi Vol. 59, No. 9, 478-483 (2012)

  According to the measurement method described in Patent Document 1, it is necessary to sample the immersed rice grains every time it is measured, and therefore it is difficult to continuously measure changes over time for the same rice grains. Moreover, since the operation | work which wipes off excess water | moisture content from the rice grain immersed in water and measures a weight change is needed, the dispersion | variation in the degree of water removal will have a big influence on a measured value as it is. Therefore, the measurement method is complicated and has a large error, and is not suitable for grasping the change in the moisture content over time. Therefore, complicated operations are required to evaluate the moisture content of rice every time the dipping process is performed, skill is required to evaluate the moisture content with high reliability, and reliability is required to obtain an accurate moisture content. The current situation is insufficient.

  Moreover, even when performing measurement by MRI, although it is possible to continuously measure changes over time for the same rice grains after immersion, the apparatus configuration becomes large and special sampling is required. Since the measurement requires complicated work, the change in the water content cannot be easily grasped.

  Therefore, the present application aims to provide a technique that can easily and accurately evaluate the water content of rice immersed in water and can help to suitably control the texture of cooked rice after cooking. .

The characteristic configuration of the method for determining the water content of rice-cooking rice of the present invention for achieving the above object is as follows:
Rice cooked by optically monitoring the rice-cooked rice placed in a state immersed in water, measuring moisture content-related information related to the moisture content of the rice-cooked rice over time, and estimated from the moisture content-related information It exists in the point which detects the saturation state of the moisture content of object rice, and determines that rice for rice cooking is the moisture state suitable for rice cooking.

  When the rice to be cooked is placed in a state immersed in water, water penetrates the rice and the moisture content of the rice gradually increases. At this time, rice expands by absorbing moisture, or the intensity of transmitted light changes. Hereinafter, the information that changes in state as the rice absorbs water is referred to as “moisture content related information”.

  In addition, in the case of “immersing in water”, the water is not limited to water at room temperature, but includes water that has been cooled and heated, and the temperature at which it is immersed in water is not limited. In addition to the case where only rice is immersed in water, other ingredients such as cooked rice are immersed together or other ingredients such as seasonings and fruit juice are dissolved in water. Cases are also included in the state of “immersing in water”.

  Changes in the moisture content of rice at this time vary depending on the brand (type) of rice, production area, harvest time, etc., and also change depending on the storage condition, storage period, etc., so it can be managed by the time immersed in water. It is not a thing. Therefore, even when rice of the same brand is cooked at the same setting soaking time, if the moisture content of the rice is not sufficient, it becomes a cooked rice with a stiff texture, and if the moisture content becomes high, There may be a large difference in taste, such as cooked rice with a crisp texture.

  This moisture content related information can be optically monitored, and the moisture content of rice can be obtained in correspondence with the moisture content related information. Therefore, by optically monitoring the rice soaked in water, changes in the moisture content of the rice can be observed over time. When this change in moisture content with time is reduced, it is considered that the rice has become saturated by absorbing water that can normally contain water. At this point, the rice has a moisture content suitable for cooking. Before this point, the moisture content is insufficient and the cooked rice has a stiff texture even after cooking.If the water content is saturated and the water is kept immersed, the water content in the rice is reduced. When it becomes supersaturated, it becomes cooked rice with a sticky texture even after cooking, and the taste is lowered.

  Therefore, by detecting the saturation state of the moisture content of rice, it can be determined that the rice is in a moisture state suitable for cooking rice. That is, it is possible to quantitatively determine that the rice is in a water-containing state suitable for rice cooking by a simple method and apparatus that only optically monitors the rice.

  In addition, since the water content is determined by optically observing rice, even when cooking rice that contains materials other than rice, such as cooked rice, materials other than rice and dissolution Since the moisture content can be measured without being affected by the components, it can be used effectively.

  Thus, when the rice determined to be in a water-containing state suitable for cooking rice is cooked, it can be provided as cooked rice that is excellent in texture and can be easily evaluated as delicious.

  Various methods can be used to determine whether the moisture content of the rice is saturated. For example, a method of determining a saturated state when the value of the measured value corresponding to the moisture content exceeds a predetermined threshold, or saturation when the rate of change of the measured value corresponding to the moisture content becomes smaller than the predetermined threshold It is a method of determining the state. As a threshold value used in such a case, a value taking into account an allowable range set in consideration of measurement error, the degree of influence at the time of rice cooking, and the like can be used as appropriate.

  Moreover, various methods can be employ | adopted also about the measuring method of moisture content related information so that it may be illustrated below.

  The said moisture content related information can be made into the expansion coefficient calculated | required from the change of the magnitude | size of the rice cooking object rice accompanying the water absorption of the rice cooking object rice obtained by monitoring the light from rice cooking object rice.

  When the light from the rice to be cooked is monitored, it is possible to observe a phenomenon in which the rice expands as the rice absorbs water. That is, when the light from rice is monitored, the size of the rice to be cooked changes due to the water absorption of the rice to be cooked, so that the expansion rate of the rice can be measured. The expansion rate of rice can be handled as moisture content related information having a correlation with the moisture content of rice. Therefore, if the moisture content is estimated using the expansion rate as the moisture content related information and the saturated state of the moisture content of the rice to be cooked is detected, it can be determined that the rice is in a moisture content suitable for cooking rice. In addition, the size of the rice to be cooked may be obtained by a plan view, that is, by monitoring from above in the vertical direction, may be obtained by a side view, that is, by monitoring from a direction orthogonal to the vertical direction, or may be observed from other directions. May be obtained.

Therefore, for example, it is possible to determine that the rice to be cooked is in a water-containing state suitable for rice cooking by a simple device that can monitor light from the rice to be cooked such as an optical camera device.
Moreover, since it can determine with a simple structure, it can apply easily also to rice cooking equipment, and can utilize for controlling the food texture of the cooked rice after cooking.

  The moisture content related information can be the transmitted light intensity associated with the water absorption of the rice to be cooked obtained by monitoring the transmitted light from the rice to be cooked.

  When the transmitted light is monitored as light from the rice, the intensity of the transmitted light changes as the rice absorbs water. That is, when the transmitted light from the rice is monitored, the light transmittance associated with the water absorption of the rice to be cooked changes, so the transmitted light intensity associated with the water absorption of the rice can be obtained. The light transmittance of rice is estimated to decrease due to the loss of light transmittance due to the change in the physical properties of starch with the improvement of moisture content (although not bound by theory, the crystal structure of starch It can be explained that water molecules infiltrate between the starch chains that make up the starch chain, which increases the distance between the starch chains, promotes scattering of the transmitted light, and decreases the transmitted light intensity). It can be handled as moisture content related information having a correlation with moisture content. Therefore, if the moisture content is estimated using the transmitted light intensity as the moisture content related information and the saturation state of the moisture content of the rice to be cooked is detected, it can be determined that the rice is in a moisture content suitable for cooking.

  Therefore, for example, it is possible to determine that the rice is in a water-containing state suitable for rice cooking with a simple device capable of monitoring transmitted light such as an optical microscope device. Moreover, since it can determine with a simple structure, it can apply easily also to rice cooking equipment, and can utilize for controlling the food texture of the cooked rice after cooking.

The characteristic configuration of the immersion time determination device of the present invention for achieving the above object is as follows:
Equipped with a monitoring unit that optically monitors rice-cooking rice placed in a state immersed in water, measuring moisture content-related information related to the moisture content of rice-cooking rice over time, and estimating from the moisture content-related information It is in the point provided with the saturated soaking time calculating part which calculates | requires the saturated soaking time required for the moisture content of the rice cooking object rice made to reach a saturated state.

  Here, the water content related information related to the moisture content of the rice to be cooked can be measured over time by optically monitoring the rice to be cooked arranged in a state immersed in water. Thereby, the moisture state of rice can be observed over time. Moreover, since the moisture content related information is information correlated with the moisture content of rice, the moisture content of rice can be estimated from the moisture content related information. Therefore, the saturated soaking time calculation unit can determine the saturated soaking time required for the moisture content of the rice to reach a saturated state by analyzing the temporal change in the moisture content of the rice based on the moisture content related information.

  Therefore, it can be determined that the rice is in a water-containing state suitable for cooking rice, and can be used to set a set immersion time for immersing the rice in water based on the saturated immersion time. Therefore, it can be easily applied to immersion rice cooking equipment and can be used to suitably control the texture of cooked rice after cooking.

In order to achieve the above object, the characteristic configuration of the rice cooking facility of the present invention is:
A rice cooking facility provided with a rice cooking apparatus that immerses the rice to be cooked in water and receives the rice to be cooked in the soaking apparatus and cooks it.
The immersion time determination device is provided, the set immersion time is set based on the saturated immersion time calculated by the saturated immersion time calculation unit, and the rice to be cooked immersed in the immersion device is immersed in the set immersion time water. It is in the point provided with the immersion completion control part which detects this and takes out rice for rice cooking from the said immersion device, and makes it transfer to a rice cooking device.

  Since the above rice cooking equipment is equipped with a soaking device, it can be soaked in water to a water-containing state suitable for cooking rice, and since it has a rice cooking device that accepts the absorbed water and cooks it, cook the absorbed rice Cooked rice can be obtained.

  Here, since the immersion time determination device is provided, the rice-cooking rice arranged in a state immersed in water is optically monitored, and the moisture content-related information related to the moisture content of the rice-cooking rice is measured over time. be able to. Thereby, the moisture state of rice can be observed over time. Therefore, the saturated immersion time can be determined by the immersion time determination device.

  Therefore, the set soaking time is set based on the obtained saturated soaking time, and the rice obtained by soaking the rice to be cooked soaked in the soaking apparatus in the water for the set soaking time reaches the saturated moisture content, and the rice cooked It can be said that it is in a water-containing state suitable for. Therefore, the moisture content of the rice can be appropriately controlled by detecting that the rice is immersed in the set immersion time. When the rice thus obtained is taken out of the dipping device by the dipping completion control unit and transferred to the rice cooker, the rice having an appropriate moisture content can be cooked quickly. Therefore, it is possible to determine that the rice is in a water-containing state suitable for cooking with a simple device that only optically monitors the rice, and to provide cooked rice with an excellent texture.

  Moreover, you may provide the immersion time input part which inputs setting immersion time to the said immersion completion control part.

  When the set soaking time determined by the soaking time determination device is input to the soaking completion control unit, the soaking completion control unit soaks the rice for the set soaking time, so that the moisture content reaches a saturated state and is suitable for cooking rice. The water content can be increased.

Here, the soaking completion control unit obtains the saturated soaking time from the soaking time determination device for each rice cooking target rice every time the rice cooking target rice is soaked in water in order to make the rice cooking target water-containing state suitable for cooking rice. In addition, each set immersion time may be set directly based on each saturated immersion time.
On the other hand, when the immersion time input unit is provided, the rice-cooking target rice is immersed in water only once to obtain a water-containing state suitable for cooking, and the saturated immersion time is acquired only once from the immersion time determination device, and the set immersion time is set. About the setting immersion time of the rice rice for rice cooking set after that, it can be set as the structure using what set the setting immersion time input into an immersion time input part as setting immersion time.

  In such cases, it is considered that rice can be cooked using a common set soaking time in common lots where the rice production area, brand, harvest time, storage method, period, etc. are clear. It is possible to manually set the set soaking time in the case of cooking by applying a common set soaking time to the rice, and it is possible to cook rice in a water-containing state more easily and reliably.

The characteristic configuration of another rice cooking facility of the present invention for achieving the above object is as follows:
A rice cooking facility provided with a rice cooking apparatus that immerses the rice to be cooked in water and receives the rice to be cooked in the soaking apparatus and cooks it.
The dipping device comprises a sampling unit that samples a part of the rice to be cooked, and a monitoring unit that optically monitors the rice to be cooked collected in the sampling unit in water,
The moisture content related information related to the moisture content of the rice to be cooked is measured over time by the monitoring unit, and the saturation state of the moisture content of the rice to be cooked estimated from the moisture content related information is detected. It is in the point provided with the immersion completion control part which takes out from the said immersion device and transfers to a rice cooking device.

  Since the above rice cooking equipment is equipped with a soaking device, it can be soaked in water to a water-containing state suitable for cooking rice, and since it has a rice cooking device that accepts the absorbed water and cooks it, cook the absorbed rice Cooked rice can be obtained.

Here, since the monitoring part which optically monitors the rice cooking object rice arrange | positioned in the state immersed in water was provided, the moisture content relevant information relevant to the moisture content of the rice cooking object rice can be measured with time.
Thereby, the moisture state of rice can be observed over time. Moreover, since the moisture content related information is information correlated with the moisture content of rice, the moisture content of rice can be estimated from the moisture content related information. As a result, it is possible to detect the saturation state of the moisture content of rice by analyzing the temporal change of the moisture content of rice based on the moisture content related information.

  Moreover, in this structure, since the immersion apparatus has provided the sampling part which samples a part of rice for rice cooking, and makes the monitoring object the rice extract | collected by the said sampling part, the rice immersed in the immersion apparatus inside Can be observed directly. Therefore, it is possible to simultaneously determine the set soaking time based on detecting the saturated state of the moisture content of the rice while soaking the rice.

  Then, based on the obtained set immersion time, when the rice-cooking rice soaked in the soaking apparatus is immersed in water, the obtained rice is a water-containing state suitable for rice cooking according to the method for determining the water-containing state of the rice-cooking rice described above. Can be determined. Therefore, the moisture content of rice can be controlled appropriately. When the rice thus obtained is taken out of the dipping device by the dipping completion control unit and transferred to the rice cooking device, the rice having an appropriate moisture content can be cooked quickly. Therefore, it can be immersed in water for an accurate time, and can shift from immersion to cooking. Therefore, it is possible to determine that the rice is in a water-containing state suitable for cooking with a simple device that only optically monitors the rice, and to provide cooked rice with an excellent texture.

Therefore, the moisture state of the rice immersed in water can be evaluated simply and accurately, and it can help to control the texture of the cooked rice after cooking.
In addition to maintaining the delicious taste of cooked rice, it is also possible to maintain the increased cooking of rice during rice cooking and stabilize the quality of cooked rice. Various benefits can be expected.

Schematic diagram of rice cooking equipment A graph showing the change over time of the expansion coefficient of rice obtained optically Graph showing the time-dependent change in the moisture content of rice measured with a moisture meter Graph showing the correlation between expansion rate and moisture content Graph showing the distribution of transmitted light intensity between unimmersed rice and immersed rice Graph showing the change over time of the dark ratio of rice obtained optically Graph showing the correlation between darkness and moisture content Graph showing the change over time of the average brightness of rice obtained optically Graph showing the time-dependent change in the moisture content of rice measured with a moisture meter Graph showing the correlation between average brightness and moisture content Graph showing the change over time of expansion rate of tomato rice Schematic of the immersion device of another embodiment

  Below, the moisture content determination method of the rice cooking object rice concerning embodiment of this invention, the immersion time determination apparatus, and rice cooking equipment are demonstrated. Preferred embodiments will be described below, but these embodiments are described in order to more specifically illustrate the present invention, and various modifications can be made without departing from the spirit of the present invention. The present invention is not limited to the following description.

[Method of judging moisture content of rice for cooking rice]
The method for determining the water content state of rice to be cooked according to an embodiment of the present invention optically monitors rice to be cooked arranged in a state immersed in water using, for example, a DMS (digital microscope) as an optical microscope device. Then, as moisture content related information related to the moisture content of the rice, for example, the change in the expansion rate or transmitted light intensity of the rice is measured over time, and the moisture content of the rice to be cooked estimated from the moisture content related information A saturated state is detected and it is determined that the rice to be cooked is in a water-containing state suitable for rice cooking.

In addition, the expansion rate is, for example, monitoring the reflected light from the rice to be cooked with a camera device, monitoring the size (area) of the rice to be cooked in the obtained image or video, and accompanying the water absorption of the rice to be cooked It can be determined from the change in the size of the rice to be cooked. For example, the ratio of the change in the size of the rice to be cooked after water absorption (expansion) relative to the size of the rice to be cooked before water absorption is defined as the expansion rate.
In addition, the transmitted light from the rice to be cooked is monitored with the camera device, not the reflected light from the rice to be cooked, and the size (area) of the rice to be cooked in the obtained image or video is monitored. It can also be determined from the change in the size of the rice to be cooked due to water absorption.

  Here, the size of the rice to be cooked may be obtained by a plan view, that is, by monitoring from above in the vertical direction, may be obtained by a side view, that is, by monitoring from a direction orthogonal to the vertical direction, or from other directions. It may be obtained by observation. Observations from multiple directions may be combined. The internal structure and composition of rice may be anisotropic. For example, in Japanese rice, the endosperm cell arrangement is not radial, and the thickness direction (short axis direction in the cross section perpendicular to the longitudinal direction) is hard with starch tightly packed and water is unlikely to penetrate. Then, when the size changes (increases) in the thickness direction, it can be estimated that water has sufficiently penetrated into the rice, and it can be determined that the water content is more suitable for rice cooking. Therefore, observation in the thickness direction is important. The observation from the side view described above is useful because it is easy to observe the change in the size of the rice seen in the thickness direction.

  The transmitted light intensity is obtained, for example, by monitoring the transmitted light from the rice to be cooked with a microscope device and measuring the transmitted light intensity associated with water absorption of the resulting rice to be cooked. For example, the rice cooking target rice before water absorption is irradiated with light and digitized into 256 gradations with a background (bright) area of 255 and an opaque (dark) area of 0, so that the rice cooking target rice is transmitted. The light intensity distribution can be measured.

  Examples of specific embodiments of an immersion time determination device and a rice cooking facility for performing such a moisture content determination method for rice cooking target rice are shown below.

[Cooking rice equipment]
As shown in FIG. 1, the rice cooking facility according to the embodiment of the present invention includes a dipping device 2 that immerses rice to be cooked rice (hereinafter sometimes simply referred to as rice) r supplied from the rice washer 1 in water. And the rice cooking apparatus 3 which receives the rice cooking object rice r absorbed in the immersion device 2 and cooks by heating is provided.
Moreover, it is provided with the immersion time determination apparatus 4 which calculates | requires the saturation immersion time required for the water content of the rice r for rice cooking to reach a saturated state in the immersion apparatus 2, and the rice r immersed in the set immersion time in the immersion apparatus 2 is the rice cooking apparatus 3. It is provided with a transfer device 5 for transferring it.
In addition, the set soaking time is set based on the saturated soaking time, the rice cooking target rice r soaked in the soaking apparatus 2 is detected to be soaked in the set soaking time, and the rice cooking target rice r is taken out from the soaking apparatus 2. And an immersion completion control unit 61 that is transferred to the rice cooker 3.
Furthermore, the control apparatus 6 provided with the rice transfer control part 62 which controls operation | movement of the transfer apparatus 5, the heating control part 63 which controls the heating of the rice cooking apparatus 3, etc. is provided.
The control device 6 is composed of a microcomputer equipped with a CPU, a memory, etc., and controls the operation of each immersion device 2, immersion time determination device 4, transfer device 5, and rice cooking device 3, so that the immersion device 2, immersion time is controlled. It functions as a part of the determination device 4, the transfer device 5, and the rice cooking device 3.

[Immersion time determination device]
The soaking time determination device 4 includes a monitoring unit that optically monitors rice-cooking rice arranged in a state immersed in water, measures moisture content-related information related to the moisture content of the rice-cooking rice over time, A saturated soaking time calculation unit for obtaining a saturated soaking time required for the moisture content of the rice to be cooked estimated from the moisture content related information to reach a saturated state is provided. In addition, the immersion completion control part mentioned above may function as a saturated immersion time calculating part.

  Specifically, a part of the rice to be cooked r is sampled and washed, and the rice holding unit 41 is arranged so as to be immersed in water, and the change in the size of the rice to be cooked r due to water absorption is changed over time. A DMS 42 is provided as a monitoring unit for monitoring and measuring, and together with the dipping completion control unit 61, a saturated dipping time for the water content of the rice r to reach a saturated state can be determined freely.

The rice image captured by the DMS 42 is transmitted to the immersion completion control unit 61 of the control device 6.
The soaking completion control unit 61 determines a contour line for each rice grain based on the video data, and analyzes how the area within the contour line changes with time. For example, when the amount of change in area calculated as (measured area / area at the start of immersion) exceeds a predetermined threshold, or for example, (area at elapsed time t / area at elapsed time t + Δt) When it is detected that the rate of change has fallen below a predetermined threshold (in FIG. 2, the rate of change of the area is 0.05% / min or less), the moisture content of the rice has reached saturation and the moisture content suitable for cooking rice The state is determined (at the time indicated by the arrow in FIG. 2).

  In addition, it can replace with DMS42 and can also use an optical camera apparatus, and it can replace with measuring the expansion coefficient of rice from the transmitted light of rice, and can also measure the expansion coefficient of rice from the reflected light of rice. Various methods can be used to determine whether the water content of the rice is saturated. For example, a method of determining a saturated state when the measured value corresponding to the moisture content exceeds a predetermined threshold, and a saturated state when the rate of change of the measured value corresponding to the moisture content becomes smaller than the predetermined threshold. It is a method of judging, a method of predicting the time to reach the saturation state from the rate of change of the measured value corresponding to the moisture content.

[Immersion equipment]
The dipping device 2 includes a dipping container 21 for weighing and receiving the washed rice r supplied from the rice washer 1 and receiving water according to the weight of the rice and dipping and holding the rice r in the water. 21 is provided with a take-out port 22 for taking out the soaked rice r, and an open / close control valve 23 is provided in the take-out port 22, soaking is completed based on an opening / closing instruction from the soaking completion control unit 61, and immersed in water. The formed rice r is configured to be freely discharged from the immersion container 21.

  With such a configuration, the rice r supplied to the immersion container 21 is immersed in the water after weighing, and the immersion is completed by the opening operation of the opening / closing control valve 23 from the immersion completion control unit 61.

[Transfer device]
The transfer device 5 includes a draining unit 51 that drains the soaked rice r discharged from the take-out port 22 of the soaking device 2, and the transporting unit 52 that transports the soaked soaked rice r to the rice cooking device 3. Is provided.

  With such a configuration, the soaked rice r can be drained and then poured into the rice cooker 30 provided in the weighing unit 31 provided in the rice cooker 3 described later.

[Rice cooker]
The rice cooker 3 weighed the rice r put into the rice cooker 30 and added the water according to the amount of rice r to prepare rice cooking, and the rice cooker 3 was put into the rice cooker 30 by the heating device 32a. A heating unit 32 that cooks rice r by heating and a take-out unit 33 that loosens the cooked rice r and enables it to be taken out are provided. The rice cooker 30 prepared for cooking by the measuring unit 31 is sequentially conveyed to the heating unit 32 and the take-out unit 33 by the conveyance device 34 that is controlled by the rice transfer control unit 62 of the control device 6.

  With this configuration, the rice r received from the transfer device 5 is sequentially heated with appropriate heating by the heating control unit 63 of the control device 6 and processed into cooked rice, for example, individually in a container such as a lunch box. It can be transferred to a downstream device for packaging.

[Experimental example]
Below, the experiment example which investigated the relationship between the measurement of the moisture content of the rice cooking object rice mentioned above, the measurement of the moisture content of the rice cooking rice cooked by the immersion time determination apparatus or the rice cooking equipment and the rice cooking result will be described in detail.

[Experimental example 1: Expansion rate]
The rice to be cooked is soaked in water, observed with DMS42, the obtained image is binarized, and the area (in plan view) of the region surrounded by the contour of rice is calculated, as shown in FIG. changed. That is, the ratio (expansion rate) to the initial area (area not immersed) of the measured area at each time increases rapidly at the beginning of the immersion, for example, reaches saturation at 60 ° C. for 60 to 90 minutes. Recognize.

  Further, when the tendency of the ratio (expansion rate) was similarly examined by changing the water temperature in various ways, this tendency was the same regardless of the water temperature, but the lower the water temperature, the lower the expansion rate, but the final expansion rate was lower. You can see that it ’s big. In FIG. 2, the water temperature was changed to 10 ° C., 25 ° C., 40 ° C., and 55 ° C., and the ratio (expansion rate) was examined.

  When measuring the expansion coefficient, instead of observing with the DMS 42, for example, an optical camera device can be used to detect the contour of the rice. Further, the contour line of rice can be detected by using reflected light instead of the transmitted light of rice. In short, various techniques can be adopted as long as the observation method can detect the outline of rice using light from rice and quantitatively grasp the size of rice.

[Comparative Experiment Example 1]
In order to investigate the relationship between the expansion rate and the moisture content, the rice to be cooked in the same lot as the rice to be cooked used in the above experimental example was immersed in water, and the moisture content time of the rice was measured using a moisture meter as in the past. When the change was investigated, it became like FIG. That is, it can be seen that the water content also increases rapidly at the beginning of immersion and reaches saturation in 60 to 90 minutes.

  Further, when the correlation between the expansion rate and the moisture content was examined, it was as shown in FIG. 4, and it was found that a high correlation was obtained. Therefore, it was found that the expansion rate can be effectively used as moisture content-related information, and the texture of cooked rice can be suitably controlled by cooking rice in a suitable moisture content.

  Referring to the measurement results of moisture content with a moisture meter, it was confirmed that even when immersed at any temperature, the moisture content of the rice was saturated and the moisture content was suitable for cooking. Therefore, it was found that by measuring the expansion rate over time, detecting the saturation state of the moisture content of the rice target rice estimated from the expansion rate, it can be determined that the rice target rice is in a water-containing state suitable for cooking rice .

[Experimental Example 2: Transmitted light intensity (dark ratio)]
Rice to be cooked was immersed in water and irradiated with light, the light transmitted through the rice was observed with DMS, and the resulting image was digitally processed. As digital processing, the area surrounded by the outline of rice is divided into a large number of pixels, and each pixel is shaded in 256 gradations, with the background (bright) area being 255 and the opaque (dark) area being 0. Turned into. When the number of pixels in which the shade is included in each gradation is counted, rice that is not soaked in water (non-soaked rice) shows a concentration distribution that peaks at a shading value of about 130 to 180, and is in water for 120 minutes or more. It was found that the soaked rice (immersed rice) showed a concentration distribution having a peak value of about 70 to 120 (see FIG. 5).

Thus, when the ratio (dark ratio) of the area (pixel) that is less than or equal to 130 (threshold) as the gray value in the area (pixel) surrounded by the contour line of rice is examined in the same manner as in Example 1, the change with time is examined. It became like this. That is, it can be seen that the dark ratio increases rapidly at the beginning of immersion and reaches saturation in 60 to 90 minutes.
Moreover, when the water temperature was changed variously and the tendency of the ratio (dark ratio) was examined in the same manner, this tendency was the same regardless of the water temperature. However, the lower the water temperature, the slower the increase rate of the dark ratio, but the final It can be seen that the ratio is almost the same. In FIG. 6, the water temperature was changed to 10 ° C., 25 ° C., 40 ° C., and 55 ° C., and the ratio (dark ratio) was examined.
In addition, when measuring the transmitted light of rice, it can replace with observing by DMS and can measure a dark ratio similarly even if it uses a normal optical microscope apparatus. As the transmitted light, the transmitted light intensity of visible light or the transmitted light intensity of light of a specific wavelength can be applied, and the dark ratio can be obtained by measuring the polarization of the light. In short, various techniques can be adopted as long as the observation method can quantitatively grasp the change in intensity of transmitted light and the change in the degree of polarization due to the water content of rice.

[Comparative Experiment 2]
As in the previous comparative experimental example 1, the correlation between the dark ratio and the moisture content was examined, and the result was as shown in FIG. 7 (however, in FIG. 7, the threshold for evaluating the dark ratio was 110). That is, there is a high correlation between the dark ratio and the moisture content, and the transmitted light intensity of rice can be used effectively as moisture content related information. It was found that the feeling can be controlled appropriately.

  Referring to the moisture content measurement results with a moisture meter, the moisture content is suitable for cooking when the moisture content of the rice reaches saturation, regardless of the temperature of immersion. Measure the transmitted light intensity of rice over time, detect the saturation of the moisture content of the rice subject to rice estimated from the transmitted light intensity, and make the rice suitable for cooking It turned out that it can be determined that the state is present.

[Experimental Example 3: Transmitted light intensity (average luminance)]
As in Experimental Example 2, the rice to be cooked was immersed in water and irradiated with light, the transmitted light of the rice was observed with DMS, and the resulting image was digitally processed. As digital processing, the area surrounded by the outline of rice is divided into a number of pixels, and each pixel is digitized into 256 tones, with shades of 255 for the background (bright) area and 0 for the opaque (dark) area. did. Then, the average luminance was calculated by summing the gray values (luminances) of all the pixels in the region surrounded by the contour of the rice and dividing by the total number of pixels.

  FIG. 8 shows the results of examining the change in average luminance over time. The average luminance continues to decrease after the start of immersion, and the degree of decrease decreases with time and reaches saturation in 60 to 90 minutes. The change in average luminance over time was examined at four water temperatures of 10 ° C., 25 ° C., 40 ° C., and 55 ° C., and the same tendency was shown at each temperature.

[Comparative Experimental Example 3]
In order to investigate the correlation between the average brightness and the moisture content, the moisture content of the rice in the same lot as that used in Experimental Example 3 was examined using a moisture meter. The result is shown in FIG. Similar to the previous experimental example, the moisture content quickly increased at the beginning of the immersion and reached saturation in 60 to 90 minutes.

  When the correlation between the average luminance and the moisture content was examined, it was as shown in FIG. 10, and it was found that there was a high correlation between the two. Therefore, it was found that the average luminance can be effectively used as moisture content-related information, and the texture of cooked rice can be suitably controlled by cooking rice in a suitable moisture content.

[Experimental Example 4: Tomato Rice]
Except that the rice to be cooked was immersed in water containing tomato juice, the expansion rate of the rice was observed in the same manner as in Experimental Example 1, and the result was as shown in FIG. That is, even when water containing other ingredients such as cooked rice is used as the water for immersing rice, it can be seen that the relationship between the saturated soaking time and the expansion rate does not change greatly, It was found that the state determination method can be applied.

[Another embodiment]
(1)
In the above-described embodiment, the rice cooking facility automatically sets the set soaking time according to the saturated soaking time determined by the soaking time determination device 4 and sequentially operates the rice washer 1, the soaking device 2, and the rice cooking device 3. However, it can replace with this and can also be set as the structure provided with the immersion time input part for inputting a setting immersion time manually based on the measured saturation immersion time. In other words, common lots where the production area, brand, harvest time, storage method, period, etc. of rice are clear can be considered to have a common saturation soaking time. The set soaking time when cooking rice having soaking time can be set manually, and rice in a water-containing state suitable for cooking can be cooked more easily and reliably.

(2)
Moreover, in the said structure, although the example which provided the immersion time determination apparatus 4 separately from the immersion apparatus 2 was shown, the immersion time determination apparatus which calculates | requires saturated immersion time separately from the immersion apparatus 2 in the continuous type for business use 4 is more versatile, and it is considered advantageous in terms of efficiency to sample and use rice for soaking time determination as needed, whereas if it is a small one, every rice cooked In some cases, it may be preferable to optimize the set immersion time. In such a case, it can also be configured as follows.

[Cooking rice equipment]
Since the rice cooking equipment concerning this embodiment can employ | adopt the same structure about the part which is common in this embodiment, description is abbreviate | omitted, but as shown in FIG. A sampling unit 41b that samples a part, and a monitoring unit 42b that includes an optical camera device 42 that optically monitors the rice cooking target rice r collected in the sampling unit 41b in a state of being immersed in water,
The monitoring unit 42b measures the size and transmitted light intensity of the rice target rice r over time, detects the saturation state of the moisture content of the rice target rice estimated from the moisture content related information, and determines the rice target rice r An immersion completion control unit 61 that is taken out from the immersion device 2 and transferred to the rice cooker 3 is provided.

In this example, the sampling part 41b is comprised by the clearance gap area | region 21c divided by the mesh-shaped wall member 21b in the translucent window 21a vicinity provided in the wall part of the immersion container 21 of the immersion apparatus 2. As shown in FIG.
In addition, when the rice r is put into the dipping device 2, the rice is automatically collected in the vicinity of the sampling unit 41b, and after the completion of the rice r addition, the mesh-like wall member 21b is placed on the translucent window 21a. By being pressed against each other, the plurality of rice r is configured to be held in a state of being in close contact with and parallel to the light transmission window 21a. In this state, when the rice r is immersed in water, the rice r inside the sampling unit 41b is immersed in water. Further, the mesh-like wall member 21b has a configuration in which when the rice r that has been immersed in water is discharged from the dipping device 2, the rice r that is separated from the translucent window 21a and collected in the gap region 21c can be easily discharged simultaneously. Become. Thereby, the moisture state of the rice r collected in the sampling unit 41b can be monitored by the monitoring unit 42b from the translucent window 21a.

  In this case, since the dipping device 2 itself includes the sampling unit 41b and the monitoring unit 42b for monitoring the rice r collected in the sampling unit 41b, the state of the rice r immersed in the dipping device 2 is directly observed. be able to. Therefore, it is possible to obtain the saturated soaking time required for the water content of the rice r to reach a saturated state simultaneously with the soaking of the rice in the soaking apparatus 2 while soaking the rice r. Moreover, since the operation | work which collects the rice r to the sampling part 41b can be made into the structure which can be automatically performed when performing the operation | work which throws the rice r into the immersion apparatus 2, it can carry out the saturated immersion of the rice more reliably with a simple structure. It is preferable because time can be managed. Further, if the light transmitting window 21a is provided on the wall of the immersion container 21 of the immersion device 2 and the monitoring unit 42b monitors from the outside, there is little need to consider the waterproofing of the monitoring unit 42b itself, and maintenance management is easy. it can.

(3)
In the above-described embodiment, DMS is used to optically measure rice over time. However, a versatile camera device or optical microscope device can be used. In addition, when measuring over time, it does not mean only observing images with a camera device, but actually observing images and taking images captured at intervals of several seconds to several tens of seconds. The case of continuous observation shall be regarded as “measurement with time”.

(4)
In addition, since the saturated immersion time depends on the environmental temperature, the immersion device and / or the immersion time determination device are provided with a thermometer and a temperature control device, and the immersion conditions in the immersion device and the immersion time determination device are the same. It can also be controlled to reach temperature. Moreover, when the temperature of an immersion apparatus and the temperature of an immersion time determination apparatus differ, setting immersion time can also be correct | amended with measurement temperature. Furthermore, when the time that can be secured as the set soaking time is short compared to the saturated soaking time (for example, when there is not enough time until the cooked target time and cooking must be started with a short set soaking time) By controlling the temperature, it is also possible to control the soaking temperature so that the preset soaking time becomes a saturated soaking time at which the moisture content of the rice reaches a saturated state.

(5)
Moreover, rice for rice cooking said to this invention is not restricted to white rice provided as rice, Brown rice may be sufficient, and glutinous rice etc. may be sufficient. Furthermore, even if it is not rice which eats directly, such as rice, as a use of rice for rice cooking, it can utilize for the determination of a moisture state for the rice heat-processed by various uses. For example, it goes without saying that the present invention can also be used in an immersion process before cooking rice for confectionery made from rice, an immersion process before making koji at the time of sake production, or the like.

(6)
In the above-described embodiment, the rice cooking facility includes the immersion time determination device 4, but the rice cooking facility may include a water content determination device. The water content determination device includes a monitoring unit that optically monitors rice cooking target rice disposed in a state immersed in water, measures moisture content related information related to the water content of rice cooking target rice over time, and A saturation determination unit is provided that detects the saturation state of the moisture content of the rice cooking target rice estimated from the moisture content related information and determines that the rice cooking target rice is in a moisture containing state suitable for cooking rice. In a saturation determination part, determination is performed using the moisture content determination method of the rice cooking object rice mentioned above.

  The rice cooking equipment provided with a water content determination apparatus can be configured as follows. The rice cooking facility includes a dipping device 2, a rice cooking device 3, a water content determination device, and a dipping completion control unit 61. The soaking apparatus 2 immerses the rice to be cooked in water. The rice cooker 3 receives and cooks the rice to be cooked that has been absorbed by the dipping device 2. The moisture content determination device detects the saturation state of the moisture content of the rice cooking target rice estimated from the moisture content related information, and determines that the rice cooking target rice is in a moisture content suitable for cooking rice. When it is determined that the rice-cooking target rice is in a water-containing state suitable for rice cooking, the soaking completion control unit 61 takes the rice-cooking rice from the soaking apparatus 2 and transfers it to the rice cooking apparatus 3.

(7)
In the above-described embodiment, the experimental example using the dark ratio and the average luminance as the transmitted light intensity is shown. As the transmitted light intensity, other information obtained from optical monitoring can be used. For example, the gradation (peak intensity) to which the most pixels (pixels) belong in the density distribution in the region surrounded by the contour line of rice may be used. Alternatively, a value (total luminance) obtained by adding all the gradations of pixels corresponding to rice may be used.

(8)
In the above Experimental Example 2 and Comparative Experimental Example 2, it was shown that there is a high correlation between the dark ratio and the moisture content. In Experimental Example 3 and Comparative Experimental Example 3, it was shown that there is a high correlation between the average luminance and the moisture content. Then, the transmitted light intensity of the rice is measured over time, the transmitted light intensity, that is, the saturation state of the moisture content of the rice to be cooked is detected from the dark ratio or the average luminance, and the water content state in which the rice to be cooked is suitable for cooking It was shown that it can be determined. In this determination, the water-containing non-uniformity in the rice is further observed, and when the non-uniformity is eliminated, it may be determined that the rice to be cooked is in a water-containing state suitable for cooking.

  The dark ratio and the average luminance can be said to be a numerical value for grasping the overall moisture content of rice, but even if these values indicate a saturated state of the moisture content, the moisture content may be uneven depending on the position. To explain, water absorption into rice proceeds not only from the surface but also from cracks and germ marks. Then, even if the dark part of the image increases as a whole due to water absorption from cracks or the like, there may be a part that is partially bright, that is, a part where water absorption is not sufficient. When cooking in such a state, a hard part may remain in the cooked rice after cooking. About such rice, it is suitable to further absorb water and cook rice after the non-uniformity is eliminated. By determining in consideration of non-uniformity as described above, it is possible to further appropriately determine that the rice to be cooked is in a water-containing state suitable for cooking.

  The determination of elimination of the non-uniformity may be made based on, for example, a density distribution (luminance distribution) in a captured image of rice as shown in FIG. Specifically, when 70% or more of all the pixels are distributed within a range of ± 10 of the maximum luminance in the luminance distribution, it may be determined that the non-uniformity has been eliminated. The determination of non-uniformity may be made on the condition that the standard deviation of the luminance distribution is below a predetermined threshold, or that the FWHM (full width at half maximum) of the luminance distribution is below a predetermined threshold.

(9)
The above-described optical monitoring and measurement of moisture content related information may be performed on a single rice (rice grain). Moreover, it may carry out with respect to several rice grains, the numerical values, such as the obtained dark ratio and average brightness | luminance, may be averaged among several rice grains, and the saturation state of a moisture content may be estimated using an average value.

  The water-containing state determination method and rice cooking equipment of the rice cooking object rice of this invention can be utilized in providing the cooked rice excellent in texture.

DESCRIPTION OF SYMBOLS 1: Rice-washing machine 2: Immersion apparatus 21: Immersion container 22: Extraction port 23: Opening-closing control valve 3: Rice-cooking apparatus 30: Rice-cooking pot 31: Measuring part 32: Heating part 32a: Heating apparatus 33: Extraction part 34: Conveying apparatus 4 : Immersion time determination device 41: Rice holding part 42: DMS (monitoring part)
5: Transfer device 51: Draining unit 52: Transfer unit 6: Control device 61: Immersion completion control unit (saturated immersion time calculation unit)
62: Rice transfer control unit 63: Heating control unit r: Rice to be cooked (rice)

Claims (7)

  Rice cooked by optically monitoring the rice-cooked rice placed in a state immersed in water, measuring moisture content-related information related to the moisture content of the rice-cooked rice over time, and estimated from the moisture content-related information A method for determining the moisture content of a rice to be cooked by detecting a saturation state of the moisture content of the target rice and determining that the rice to be cooked is in a moisture content suitable for cooking rice.   2. The rice target rice according to claim 1, wherein the moisture content related information is an expansion rate obtained from a change in size of the rice target rice accompanying water absorption of the rice target rice obtained by monitoring light from the rice target rice. Method for determining water content of   The water content determination method for rice cooking target rice according to claim 1, wherein the moisture content related information is transmitted light intensity associated with water absorption of the rice cooking target rice obtained by monitoring transmitted light from the rice cooking target rice.   Equipped with a monitoring unit that optically monitors rice-cooking rice placed in a state immersed in water, measuring moisture content-related information related to the moisture content of rice-cooking rice over time, and estimating from the moisture content-related information The soaking time determination apparatus provided with the saturated soaking time calculating part which calculates | requires the saturated soaking time required for the moisture content of the rice cooking object rice made to reach a saturated state. A rice cooking facility provided with a rice cooking apparatus that immerses the rice to be cooked in water and receives the rice to be cooked in the soaking apparatus and cooks it.
The immersion time determination apparatus according to claim 4, wherein a set soaking time is set based on the saturated soaking time obtained by the saturated soaking time calculating unit, and the rice to be cooked soaked in the soaking apparatus is the set soaking time. A rice cooking facility provided with an immersion completion control unit that detects that the rice is soaked in water and takes out the rice to be cooked from the soaking apparatus and transfers it to the rice cooking apparatus.   The rice cooking facility according to claim 5, further comprising an immersion time input unit for inputting a set immersion time to the immersion completion control unit. A rice cooking facility provided with a rice cooking apparatus that immerses the rice to be cooked in water and receives the rice to be cooked in the soaking apparatus and cooks it.
The dipping device comprises a sampling unit that samples a part of the rice to be cooked, and a monitoring unit that optically monitors the rice to be cooked collected in the sampling unit in water,
The moisture content related information related to the moisture content of the rice to be cooked is measured over time by the monitoring unit, and the saturation state of the moisture content of the rice to be cooked estimated from the moisture content related information is detected. The rice cooking equipment provided with the immersion completion control part which takes out from the said immersion device and transfers to a rice cooking device.

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