Acid value measuring device, acid value measuring program

Abstract

To provide a technique of measuring the acid number of edible oil at low cost without depending on the subjective view of an observer.SOLUTION: An acid number measuring device 4 for measuring the acid number of a fat includes: an oil type setting unit 402 for setting the oil type of a measurement fat to measure; an image acquisition unit 401 for acquiring an image taken of the measurement fat; and a calculation unit 405 for calculating the acid number of the measurement fat on the basis of the value of at least one primary color of the colors of the measurement fat in the image and the coefficient and the constant related to the set oil type.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] Embodiments of the present invention relate to a technique for measuring the acid value of edible oil.

Background Art

[0002] In deep-frying, where food ingredients are immersed in heated edible oil and fried, if the oxidation reaction of the edible oil progresses due to repeated use, the quality of the fried food deteriorates. At the site of deep-frying, the acid value of the used edible oil is measured to determine the timing of replacing the used edible oil with new edible oil.

[0003] Generally, for measuring the acid value of edible oil, an AV (Acid Value) test paper is used as a measurement method that does not require expensive measuring equipment and does not require specialized knowledge. The acid value measurement using an AV test paper is performed by immersing the test section of the AV test paper in the edible oil to be measured, and after a certain time, comparing the color of the developed test section with a color chart.

[0004] As a related technique, there is known an acid value measurement method characterized by including a step of reacting an oil and fat sample with a carboxylic acid derivative reagent, quantifying the generated carboxylic acid derivative, and calculating the acid value of the oil and fat sample from the quantified value of the carboxylic acid (see Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In measuring acid value using AV test strips, the comparison between the color of the test area and the color chart is done visually by the person performing the test, which presents a problem as the measurement results can be inaccurate due to the subjective judgment of the person performing the test.

[0007] The problem that this invention aims to solve is to provide a technology for measuring the acid value of edible oil at low cost without relying on the subjective judgment of the measurer. [Means for solving the problem]

[0008] To solve the above-mentioned problems, one aspect of the present invention is an acid value measuring device for measuring the acid value of oils and fats, comprising: an oil type setting unit for setting the oil type of the oil to be measured; an image acquisition unit for acquiring an image of the oil to be measured; and a calculation unit for calculating the acid value of the oil to be measured based on the value of at least one primary color of the color of the oil to be measured in the image, and coefficients and constants associated with the set oil type. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a technique for measuring the acid value of edible oil at low cost without depending on the subjective judgment of the measurer. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram showing the configuration of the acid value measurement system according to the embodiment. [Figure 2] This is a side view showing the configuration of the sampling device according to the embodiment. [Figure 3] This is a block diagram showing the hardware configuration of an acid value measuring device according to an embodiment. [Figure 4] This is a block diagram showing the functional configuration of an acid value measuring device according to an embodiment. [Figure 5] This is a flowchart showing the operation of the acid value measuring device according to the embodiment. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the drawings. In this specification and the drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant explanations will be omitted.

[0012] (Configuration of the acid value measurement system) The configuration of the acid value measurement system according to this embodiment will now be described. Figure 1 is a schematic diagram showing the configuration of the acid value measurement system. Figure 2 is a side view showing the configuration of the sampling device.

[0013] As shown in Figure 1, the acid value measurement system 1 according to this embodiment comprises a sampling tool 2 for collecting the oil O to be measured, a color chart 3, and an acid value measuring device 4. The acid value of the oil O is measured by the acid value measuring device 4 calculating the acid value based on the captured image IM of the oil O. In this embodiment, the oil to be measured is edible oil, and examples of such edible oils include vegetable oils such as corn oil, sunflower oil, rapeseed oil, sesame oil, olive oil, cottonseed oil, palm oil, palm kernel oil, coconut oil, peanut oil, safflower oil, and soybean oil.

[0014] As shown in Figures 1 and 2, the sampling device 2 is formed in a cylindrical shape with a closed bottom and an open top, and has a storage section 21 for storing the oil O to be measured, and a gripping section 22 which is formed in a roughly rod shape extending in one direction, with one end connected to the storage section 21. The sampling device 2 according to this embodiment is made entirely of stainless steel, has an uncolored silver surface, and has an inner diameter DM of 25 mm and a depth DP of 10 mm in the storage section 21. As will be described later, since the acid value measuring device 4 calculates the acid value based on the color of the oil O, it is desirable that the sampling device 2 has a surface with relatively high reflectivity and low saturation.

[0015] As shown in Figure 1, the color chart 3 is formed as a rectangular sheet large enough to accommodate the sampling device 2, and one side of it is marked with four markers M, three color symbols CS, and a border line FL. The four markers M are two-dimensional codes identifiable by the acid value measuring device 4 and are drawn near the four corners of the color chart 3. Each of the four markers M is a two-dimensional code encoded with a different identifier, which allows the acid value measuring device 4 to measure the position of each of the four corners of the color chart 3 in the captured image IM.

[0016] The three color symbols CS are used as a reference for correcting the color of the oil O in the captured image IM, as will be described later. In this embodiment, they are colored with red (R), green (G), and blue (B), which are the primary colors in the RGB color model. Note that it is sufficient for at least one color symbol CS to be drawn, and it may be a color other than red, green, or blue. The frame line FL is a dotted line that represents the sampling device 2 in plan view and indicates the position where the sampling device 2 should be placed. When measuring the acid value of the oil O, the measurer places the sampling device 2, which contains the oil O to be measured, on the color chart 3 so that it is within the frame line FL.

[0017] (Configuration of the acid value measuring device) The configuration of the acid value measuring device according to this embodiment will now be described. Figures 3 and 4 are block diagrams showing the hardware configuration and functional configuration of the acid value measuring device, respectively.

[0018] As shown in FIG. 3, the acid value measuring device 4 is configured as a tablet-type terminal device used by a measurer of the oil or fat O. As hardware, it includes a CPU (Central Processing Unit) 41, a RAM (Random Access Memory) 42, a storage device 43, a touch panel 44, and a camera 45. The CPU 41 and the RAM 42 cooperate to execute various functions, and the storage device 43 stores various data used for the processes executed by the various functions. The touch panel 44 has a display and a touch sensor, and is an input / output device provided on the front side of the acid value measuring device 4. The camera 45 is provided on the back side of the acid value measuring device 4, and is an imaging device that captures a two-dimensional image and video using visible light.

[0019] As shown in FIG. 4, the acid value measuring device 4 includes, as functions, an image acquisition unit 401, an oil type setting unit 402, an extraction unit 403, a correction unit 404, and a calculation unit 405. The image acquisition unit 401 acquires a captured image IM captured by the camera 45. The oil type setting unit 402 sets the oil or fat O for which the acid value is to be measured to the oil type selected by the measurer. The extraction unit 403 extracts partial images of the oil or fat O and each of the three color symbols CS from the captured image IM acquired by the image acquisition unit 401. The correction unit 404 corrects the color of the partial image of the oil or fat O based on the partial images of the three color symbols CS. The calculation unit 405 calculates the acid value of the oil or fat O based on the coefficient, constant, and threshold associated with the set oil type and the color of the corrected partial image of the oil or fat O. In this embodiment, the RGB value of pixels satisfying specific conditions within the partial image, or the average value of the RGB values of all pixels within the partial image is used as the color of the partial image.

[0020] The coefficients, constants, and thresholds associated with the oil type are preset values for each oil type and are determined based on the results of basic measurements performed prior to the use of the acid value measuring device 4. This basic measurement measures the color of the oil and fat O with different acid values for each oil type, and at least the measurement of the color of the same oil type is performed under the same environmental conditions. Specifically, for the same oil type, imaging is performed by a camera having the same camera characteristics under the same light source. In addition, in the basic measurement, the sampler 2 and the color chart 3 are used, and three color symbols CS are imaged together with the oil and fat O.

[0021] The calculation of the acid value by the acid value measuring device 4 according to the present embodiment is based on the finding that a value approximating the acid value can be calculated based on the red value or the red and green values among the colors of the oil and fat O expressed in the RGB color model. Specifically, let R be the red value, G be the green value, B be the blue value, T be the threshold, X = 2×R - G (when R≥T), X = R (when R<T), A be a negative coefficient, C be a positive constant, and Y be the acid value. Then, the acid value is calculated by Y = AX + C. Note that depending on the oil type, the threshold T is not required, and regardless of the red value, X = R is always used in the above formula to calculate the acid value. Therefore, the acid value can be calculated using only the red value of the oil and fat O. The coefficient A, the constant C, and the threshold T are stored in advance in the storage device 43 in association with the oil type.

[0022] (Operation of the acid value measuring device) The operation of the acid value measuring device will be described. FIG. 5 is a flowchart showing the operation of the acid value measuring device.

[0023] As shown in FIG. 5, first, the oil type setting unit 402 sets the oil type of the oil and fat O to be measured (S101). Here, the oil type setting unit 402 displays at least one or more oil types on the touch panel 44, and sets the oil type selected by the user from the displayed oil types as the oil type of the oil and fat O to be measured.

[0024] Next, the image acquisition unit 401 acquires an image IM of the color chart 3 on which the sampling device 2, which contains the oil O, is placed (S102). At this point, the image acquisition unit 401 prompts the user via the touch panel 44 to take an image with the camera 45 so that the entire color chart 3 is included within the imaging range.

[0025] Next, the extraction unit 403 extracts the image to be measured (S103) and a color reference image (S104) from the captured image IM acquired by the image acquisition unit 401. The image to be measured is a partial image containing oil O, and the color reference image is a partial image containing three color symbols CS. Based on the positions of four markers M in the captured image IM, the extraction unit 403 determines the image range to be extracted as the image to be measured and the color reference image.

[0026] Next, the correction unit 404 corrects the color of the image to be measured, which was extracted by the extraction unit 403, based on the color reference image extracted by the extraction unit 403 (S105). The captured image IM acquired by the image acquisition unit 401 may be captured at a measurement site with different environmental conditions than the basic measurement. Specifically, the captured image IM may be captured under a different light source than the basic measurement, and by a camera 45 having different camera characteristics than the basic measurement. In order to reduce the influence of such differences in environmental conditions on the image to be measured, the correction unit 404 corrects the color of the image to be measured based on the colors of the three color symbols CS captured in the basic measurement related to the type of oil O set as the target of measurement, and the color reference image extracted by the extraction unit 403.

[0027] The correction unit 404 calculates environmental variation factor values ​​for each of the three color symbols CS that are colored red, blue, and green, which constitute the red, blue, and green components of the RGB color model. By multiplying these environmental variation factor values ​​by the respective RGB values ​​that represent the color of the image to be measured, the unit corrects the color of the image to be measured. For example, the environmental variation factor value for red is calculated by dividing the R value of the red color symbol CS in the captured image IM taken in the basic measurement by the R value of the red color symbol CS in the color reference image.

[0028] After correcting the color of the image to be measured, the calculation unit 405 reads the coefficient A, constant C, and threshold T associated with the oil type set based on the oil type setting unit 402 from the storage device 43, and calculates the acid value using the formula Y=AX+C based on the R value or the R value and G value among the RGB values ​​that represent the color of the image to be measured corrected by the correction unit 404 (S106), and the calculated acid value is displayed on the touch panel 44.

[0029] The calculation unit 405 calculates the acid value as X=R if there is no threshold T associated with the type of oil. Furthermore, if there is a threshold T associated with the type of oil and the R value of the image being measured is greater than or equal to the threshold T, the calculation unit 405 calculates the acid value as X=2×RG. Also, if there is a threshold T associated with the type of oil and the R value of the image being measured is less than the threshold T, the calculation unit 405 calculates the acid value as X=R.

[0030] As explained above, by calculating the acid value based on the color of the oil O in the captured image IM, the acid value of edible oil can be measured at low cost without relying on the subjective judgment of the measurer.

[0031] In the embodiment described above, the acid value measuring device 4 is configured as a tablet terminal, but it may also be configured as a server that can communicate with the tablet terminal via a network. In this case, the oil type selected by the user and the captured image IM are sent from the tablet terminal to the server, and the server calculates the acid value based on the captured image and the selected oil type and sends it to the tablet terminal. In the embodiment described above, the acid value is calculated using the primary color values ​​of the RGB color model, but the acid value may also be calculated based on at least one value of the primary colors cyan, yellow, and magenta of the CYM color model, and a coefficient A, a constant C, and a threshold T corresponding to the oil type obtained from basic measurements. Furthermore, the captured image IM may be captured by an external imaging device not built into the acid value measuring device 4.

[0032] The present invention can be implemented in various other forms without departing from its essence or main features. Therefore, the embodiments described above are merely illustrative in all respects and should not be construed restrictively. The scope of the invention is defined by the claims and is not restricted in any way by the text of the specification. Furthermore, all variations, improvements, substitutions, and modifications falling within the equivalent scope of the claims are all within the scope of the invention. [Explanation of Symbols]

[0033] 4. Acid value measuring device 401 Image acquisition unit 402 Oil Type Setting Section 404 Correction Unit 405 Calculation Unit

Claims

1. An acid value measuring device for measuring the acid value of oils and fats, An oil type setting unit for setting the type of oil to be measured, An image acquisition unit that acquires an image of the measured oil, The system includes a calculation unit that calculates the acid value of the measured oil by multiplying the red value of the color of the measured oil in the captured image by a coefficient associated with the set oil type and adding a constant. A threshold is further associated with the aforementioned set oil type. The acid value measuring device is characterized in that, when the red value is equal to or greater than the threshold, the calculation unit multiplies the red value by 2, subtracts the green value in the color of the measured oil, multiplies the result by the coefficient, and adds the constant to calculate the acid value of the measured oil.

2. The captured image includes at least one color chart along with the measured oil. The acid value measuring apparatus according to claim 1, further comprising a correction unit for correcting the color of the oil to be measured based on at least one color chart in the captured image.

3. The acid value measuring device according to claim 1 or 2, characterized in that the coefficient is a negative value and the constant is a positive value.

4. An acid value measurement program for measuring the acid value of oils and fats, Computers, An oil type setting unit for setting the type of oil to be measured, The image acquisition unit acquires an image of the measured oil, with the color represented by the three primary colors of red, green, and blue. This unit functions as a calculation unit that calculates the acid value of the measured oil by multiplying the red value in the color of the measured oil in the captured image by a coefficient associated with the set oil type and adding a constant. A threshold is further associated with the aforementioned set oil type. The calculation unit is characterized in that, if the value of red is greater than or equal to the threshold, it calculates the acid value of the measured oil by multiplying the value of red by 2, subtracting the value of green in the color of the measured oil, multiplying the result by the coefficient, and adding the constant.

Images