JP3029693B2 - Horse mackerel measurement method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a sensor capable of acting as a substitute for the taste, which is one of the five senses of human beings, and uses the difference in taste of food and drink, which has been difficult to measure by an artificial sensor. The present invention relates to a technology for enabling detection and measurement. Foods such as drinking water for food and drink, the difference in taste of alcohol, etc., because it is to provide technology to detect what should be called the difference in taste, in drinking water and alcohol production plants,
The present invention relates to a technology that enables the quality control to be performed by a mechanical device without manual operation.

[0002]

[Definition of terms] It is said that there are saltiness, sweetness, bitterness, sourness, and umami as basic components of taste, each of which has a degree of magnitude. These differences in taste that can be evaluated by human senses, or differences in saltiness (of the same type) for saltyness, can be grasped as physically measurable quantities, and differences in measurable taste or taste (Comparative or contrasting taste) is herein referred to as “adzuki”.

[0003]

2. Description of the Related Art Conventionally, as disclosed in Japanese Patent Application Laid-Open No. 62-187252, for example, the concentration of each original taste (basic taste) component, that is, the concentration of a selected taste substance in an object to be measured is determined from output values of a plurality of taste sensors. Calculated values were measured for horse mackerel by correcting each density value to a value representing the strength of each taste corresponding to human taste. However, the taste sensor referred to in the above publication is a chemical sensor or a physical sensor that selectively detects a substance exhibiting each basic taste. Specifically, salty taste is a salt concentration meter, sourness is a hydrogen ion index meter, and sweetness is Is a saccharimeter utilizing the refractive index of the liquid to be measured. Since these sensors are selective, for example, a salt concentration meter that is trying to measure the strength of salty taste can measure the concentration of salt, but cannot measure the concentration of other substances that exhibit salty taste, and it suits human taste There was a limit to the correction. Speaking of this as a color,
It was like trying to get a color result using a sensor that only detects a single color.

[0004] The same applicant has previously filed a patent application for "taste sensor and method for manufacturing the same" (Japanese Patent Application No. Hei.
190819). In the specification and drawings of this application, a lipid substance composed of a molecule having a hydrophobic part and a hydrophilic part is fixed in a polymer matrix, and the hydrophilic part of the lipid molecule is fixed on the surface thereof. It has been shown that a lipid molecular membrane having a structure in which aligns can be a sensor for horse mackerel, that is, a taste sensor that can replace human taste.

[0005] Fig. 4 shows a membrane diagram of the lipidic molecular membrane in a representation method used in a method of designing a chemical substance. The globular part shown by a circle in the lipid molecule is a hydrophilic group a, that is, a hydrophilic part a, and there is a hydrocarbon chain structure b (for example, an alkyl group) whose atomic arrangement extends long from it. In each case, two chains are extended to represent one molecule in each case, and the whole constitutes a molecule group. This part of the hydrocarbon chain is the hydrophobic site b. Such a lipid molecule group 31 is partially dissolved in a matrix 33 (a surface structure, a microstructure having a planar spread) on the surface of the membrane member 32 (for example, It is accommodated at 31 ') in FIG. The manner of its containment is
The hydrophilic sites are arranged on the surface.

FIGS. 5 (a) and 5 (b) show a multi-channel taste sensor using this lipid molecular membrane. In this figure, three sensitive parts of the multi-channel array electrode are shown. In the illustrated example, a 0.5 mmφ hole was penetrated through the base material, and a silver round bar was inserted into the hole to form an electrode. The lipid molecular membrane is adhered to the substrate via the buffer layer so as to contact the electrode.

FIG. 6 shows a horse mackerel measuring system using the multi-channel taste sensor. Prepare an aqueous solution of the taste substance, use it as the solution to be measured 11, and place it in a container 12 such as a beaker.
Put in. The taste sensor array 13 formed by arranging a lipid membrane and electrodes on an acrylic plate (substrate) as described above was placed in the solution to be measured. Before use, potassium chloride 1m
The electrode potential was stabilized with a mole / l aqueous solution. In the figure, 14-
1,..., 14-8 indicate the respective lipid membranes by black dots. A reference electrode 15 is prepared as an electrode for generating a potential serving as a reference for measurement, and is placed in a solution to be measured. The taste sensor array 13 and the reference electrode 15 are installed at a predetermined distance. The surface of the reference electrode 15 is covered with a buffer layer 16 coated with 100 mM mole / l of potassium chloride solidified with agar, so that the electrode system is eventually composed of silver 2 | silver chloride 4 | lipid membrane 3 (14) |
Measured solution 12 | Buffer layer (potassium chloride 100mole / l)
16 | silver chloride 4 | silver 2

The electrical signal from the lipid membrane becomes an eight-channel signal in the figure, and is led to buffer amplifiers 19-1,..., 19-8 by leads 17-1,. Each output of the buffer amplifier 19 is selected by an analog switch (8 channels) 20 and applied to an A / D converter 21. The electric signal from the reference electrode 15 is also applied to the A / D converter 21 via the lead wire 18, and converts the difference from the potential from the membrane into a digital signal. This digital signal is appropriately processed by the microcomputer 22 and displayed by the XY recorder 23. In this example, an 8-channel taste sensor is used, and each channel has a different response characteristic to taste in order to obtain a lot of taste information that can reproduce human taste. It is composed of a molecular film.

[0009]

[Table 7]

[0010] The same applicant has also filed a patent application for "taste sensor and manufacturing method thereof" (Japanese Patent Application No. Hei 3-0204).
No. 50). In the specification and drawings of this application, a molecular membrane closer to human taste organs is shown than in the previous application (Japanese Patent Application No. 1-190819). Then, the structure of a molecular film capable of utilizing a substance called an amphipathic substance (including lipid) having a hydrophilic group and a hydrophobic group or a bitter substance such as an alkaloid as a material of the molecular film was shown. In this structure, as shown in FIG. 7, the amphipathic molecule group 36 or the bitter substance molecule group 36 is arranged on the base film 7 provided on the substrate 1 such that the hydrophilic site indicated by a circle faces outward, It constitutes a monomolecular film.

The taste sensor described in the specification of the same applicant is exactly a taste sensor, which has physicochemical properties close to the tongue which is a human taste organ, and has the same taste even when the taste substance is different. If so, a similar output can be obtained, and some output can be obtained for different tastes. Speaking of color, this is a sensor that can detect color.

[0012]

When a horse mackerel is detected and measured by a taste sensor using a molecular film as described in the preceding section, there are the following problems. That is, since the output characteristics are non-linear, the signal processing becomes complicated to some extent, the number of learning data becomes enormous, and the accuracy is sometimes inevitable.

An object of the present invention is to solve these problems, and to measure azimuth by a taste sensor using a molecular film, but to simplify the signal processing, to reduce the number of learning data, and to achieve an accurate azimuth measurement. Is to provide a way.

[0014]

Means for Solving the Problems The output of a taste sensor using a molecular film of an amphipathic substance or a bitter substance has been described as being non-linear, which complicates signal processing. Through experiments, it was found that the output of the taste sensor can be regarded as linear for each basic taste within a limited range. Based on this fact, the above-mentioned problem has been solved by the following method.

A plurality of taste sensors using a molecular film of an amphipathic substance or a bitter substance are used. First, the sensitivity of each taste sensor for each basic taste within a measurement range is obtained, and the sensitivity obtained in To calculate the strength of horse mackerel from the output of each taste sensor. The strength of horse mackerel was determined by determining a representative taste substance for each basic taste contained in the measurement object and converting the value into the concentration of the taste substance.

[0016]

In a certain limited range, the output of the taste sensor can be regarded as linear for each basic taste.
0 and a substance Bi exhibiting a certain amount of basic taste Ai in the reference solution E0
Is measured by the taste sensor Sj.
Basic taste (concentration of substance exhibiting) added from those outputs
The sensitivity Wij of the taste sensor Sj with respect to is determined.

Then, the reference liquid E0 is detected by the taste sensor Sj.
And the sample liquid Es is measured, and the outputs Vj0 and Vjs of the taste sensor Sj and the sensitivity Wij are substituted into the equation (1),
By solving the simultaneous equations, the concentration xi of the substance exhibiting each basic taste (
) Is obtained. Vjs−Vj0 = {Wij · log (xi / ri) (1) (The range of Σ is from i = 1 to m) where ri is a substance B having a basic taste Ai in the reference solution E0.
This is the concentration of i.

[0018]

FIG. 1 is a flow chart showing one example of a method of measuring horse mackerel according to the present invention. This figure will be explained a little. The plurality of taste sensors used for horse mackerel measurement need to have at least basic tastes of different types (having different reactions) as measurement targets. The reference liquid is similar or identical to the object to be measured. The representative taste substance is a representative of a substance exhibiting each basic taste, and is for expressing the intensity of the corresponding basic taste by the concentration of the substance in the measurement object. The sensitivity measurement liquid is prepared for each basic taste by increasing or decreasing only the concentration of the representative taste substance of each basic taste by a known amount.

Next, an example of a horse mackerel measurement using the present invention will be described. (1) Preparation stage The types of molecular films of the taste sensor Sj used are shown in Table 1. The basic taste Ai was A1 = sweet, A2 = bitter, A3 = sour, A4 = salt. B1 = sucrose, B as a substance Bi exhibiting each basic taste Ai
2 = quinine, B3 = hydrochloric acid, B4 = sodium chloride. The measuring system is similar to the measuring system shown in the specification and drawings of the same applicant's patent application (Japanese Patent Application No. 1-190819) described in the section of the prior art.
This is described in the section of the prior art of this specification. (See Fig. 6)

[0020]

[Table 1]

(2) Measurement of sensitivity Wij Object to be measured a. As a reference solution E0, sucrose 300 mM, quinine 0.15 mM,
A mixed solution of 3 mM hydrochloric acid and 200 mM sodium chloride was used. These concentrations are intermediate concentrations felt by humans for each basic taste. B. The solutions for measuring the sensitivity to sweetness were those in which only the concentration of sucrose in the reference solution E0 was 360 mM, 420 mM, 480 mM, 540 mM, and 600 mM. C. The solution for measuring the sensitivity to bitterness is only the concentration of quinine in the standard solution E0 of 0.18 mM, 0.21 mM, 0.24 mM, 0.27 mM, 0.30 mM.
It is what it was. D. The solution for measuring the sensitivity to sourness was prepared by changing the concentration of hydrochloric acid in the standard solution E0 to 3.15 mM, 3.30 mM, 3.45 mM, 3.60 mM, and 3.75 mM. E. The solution for measuring the sensitivity to salty taste is only the concentration of sodium chloride in the standard solution E0, 210 mM, 220 mM, 230 mM, 240 mM, 250 mM.
mM.

Measurement Procedure Since the measurement procedure requires measurement accuracy, the same applicant has previously filed an application “Aji Detection Method” (Japanese Patent Application No. 2-17 / 1990).
No. 6584). I. A taste sensor using a lipid membrane is immersed in a reference solution for approximately 10 hours. B. The taste sensor is taken in and out of the reference solution (for cleaning) 10 times. Washing with a reference solution (for washing), intermittent immersion in the reference solution, and stimulation of the lipid membrane surface of the taste sensor can also be performed. C. After immersion in the reference solution prepared for measurement, the potential of the taste sensor is measured 20 seconds later, and the measured value is defined as Vj0.

D. Procedure b. , C. Is repeated twice or more,
For each measurement, it is determined whether the difference between the current measured value Vj0 and the previous measured value Vj0 is equal to or less than a predetermined value, and if it is equal to or less than the predetermined value (that is, if Vj0 is stabilized), the procedure E. Proceed to. E. The taste sensor is taken out of the reference liquid (for measurement) and washed with the sample liquid to be measured (for washing). (Similar to b.
Put in and out 10 times. ) F. The taste sensor is immersed in the sample liquid to be measured (for measurement), and after 20 seconds, the potential Vjs of the taste sensor is measured. As a horse mackerel, a measured value of ΔVjs = Vjs−Vj0 is obtained.

G. Measurement procedure b. Return to step b. ,
C. , E. , F. repeat. When the process is repeated a predetermined number of times, the procedure ends. This procedure is shown in FIG.
(a), (b) and FIG. When there are a plurality of sample liquids to be measured, the measurement order of the samples may be determined so that the rotation has randomness, and the average value may be obtained by repeatedly measuring.

FIG. 2 shows the measurement results. The straight line in FIG. 2 was drawn using the least squares method. FIG. 2 shows that the logarithm of the density and the output of each taste sensor are almost linear. This inclination is the sensitivity Wij of each taste sensor Sj to the basic taste Ai. Table 2 shows the sensitivity Wij.

[0026]

[Table 2]

In this measurement, several measurement points were provided in between to show that the relationship between the logarithm of the density and the output of each taste sensor was substantially linear, but there was no measurement point between them. Is also good. Since the inclination of the straight line is obtained, it is sufficient if there are two points of known density for each basic taste.

(3) Investigation of the influence on measurement when the reference point is changed Sample liquids to be measured S100, Q100, H25, and N25, each of which has increased sweetness, bitterness, sourness, and saltiness with respect to the reference liquid E0, are prepared. It was examined whether or not there was a change in the measured relative relationship between the case where the reference liquid E0 was used as the reference point and the case where the measured sample liquids were used as the reference points.

Object to be measured a. As a reference solution E0, sucrose 300 mM, quinine 0.15 mM,
A mixed solution of 3 mM hydrochloric acid and 200 mM sodium chloride was used. B. The liquid S100 to be measured has only the sucrose concentration of the reference liquid E0 of 100
% Increase, ie, 600 mM sucrose. C. The measured liquid Q100 is only the quinine concentration of the reference liquid E0
100% increase, that is, 0.39 mM quinine. D. The solution H25 to be measured is a solution in which only the concentration of hydrochloric acid in the reference solution E0 is increased by 25%, that is, the concentration of hydrochloric acid is 3.75 mM. E. The solution to be measured N25 is a solution in which only the concentration of sodium chloride in the reference solution E0 is increased by 25%, that is, the concentration of sodium chloride is 250 mM.

Measurement procedure (2) The taste sensor Sj used in the measurement of the sensitivity Wij is immersed in a liquid serving as a reference point for 1 hour before measurement, and the remaining four liquids are added in a random order for a total of 10 liquids per liquid. Measurements were performed. Other measurement procedures are the same as (2).

Measurement result Taste sensor Sj when four kinds of liquids were measured with reference points
Is converted to an output value using the reference solution E0 as a reference point,
The standard deviation was determined. Table 3 shows the obtained standard deviations. Since the standard deviations are all very small, it can be seen that changing the reference point does not affect the measurement.

[0032]

[Table 3]

From the results of (2) and (3), the sensitivity Wij can be regarded as a constant within a limited range, and the output of the taste sensor Sj and each taste substance Bi
It can be understood that the relationship with the density xi is expressed by the following equation (1). Here, if the range is further narrowed, each basic taste Ai (concentration xi of the substance Bi exhibiting each basic taste Ai) of the sample liquid to be measured can be measured even if the relational expression of the equation (2) is used. Vjs−Vj0 = {Wij · (xi−ri) (2) (The range of Σ is from i = 1 to m.)

(4) Measurement of Measurement Object Measurement Object As a reference solution E0, sucrose 300 mM, quinine 0.15 mM,
A mixed solution of 3 mM hydrochloric acid and 200 mM sodium chloride was used. B. The sample liquid to be measured had the following two concentrations for each taste substance, and these were combined one by one. A total of 16 types of liquids are formed, one of which is a reference liquid E0. Sucrose: 300 mM, 600 mM Quinine: 0.15 mM, 0.30 mM Hydrochloric acid: 3.00 mM, 3.75 mM Sodium chloride: 200 mM, 250 mM

Measurement procedure (2) The taste sensor Sj used in the measurement of the sensitivity Wij was immersed in the reference solution E0 for one hour before the measurement, and then the measurement was performed. Other measurement procedures are the same as (2).

Measurement results Table 4 shows the measurement results. In Table 4, the symbols in the leftmost column indicate that the sample liquid to be measured has the following contents. The standard solution is sucrose 300mM, quinine 0.15mM, hydrochloric acid 3.00mM sodium chloride
It is a mixed solution of 200 mM. S is 600 mM sucrose concentration and the same as the other standard solution, Q is 0.30 mM quinine concentration and the same as the other standard solution, H is 3.75 mM hydrochloric acid concentration and the same as the other standard solution, N is the same as the standard solution. At a sodium concentration of 250 mM the others are the same as the reference solution, and SQ indicates that the sucrose concentration is 600 mM and the quinine concentration is 0.30 mM and the others are the same as the reference solution. Therefore, SQHN indicates that the concentration of sucrose is 600 mM, the concentration of quinine is 0.30 mM, the concentration of hydrochloric acid is 3.75 mM, and the concentration of sodium chloride is 250 mM.

[0037]

[Table 4]

It can be seen from Table 4 that, for example, the sum of the measured value of S and the measured value of Q is substantially equal to the measured value of SQ. That is, it can be seen that the sum of the outputs for each basic taste is the output of the entire liquid including the basic taste.

The output value of each taste sensor Sj obtained by this measurement and the sensitivity Wij obtained in (2) are substituted into equation (1), and simultaneous equations are established for each sample liquid to be measured. In this measurement, four kinds of basic tastes Ai (i = 1, 2, 3, 4) and the taste sensor S
Since j is eight types (j = 1, 2, 3, 4, 5, 6, 7, 8), the following simultaneous equations are established for each sample liquid to be measured. Here, log (xi / ri) in equation (1) is set to Xi. V1s-V10 = W11X1 + W21X2 + W31X3 + W41X4 V2s-V20 = W12X1 + W22X2 + W32X3 + W42X4 V3s-V30 = W13X1 + W23X2 + W33X3 + W43X4 V4s-V40 = W14X1 + W24X2 + W34X3 + W44X4 V5s-V50 = W15X1 + W25X2 + W35X3 + W45X4 V6s-V60 = W16X1 + W26X2 + W36X3 + W46X4 V7s- V70 = W17X1 + W27X2 + W37X3 + W47X4 V8s-V80 = W18X1 + W28X2 + W38X3 + W48X4 Table 5 shows the error ratio between the concentration xi of the substance exhibiting each basic taste and the true value obtained by solving this simultaneous equation by the least square method.

[0040]

[Table 5]

The error rate for sucrose is bad, but the error rate for other basic tastes is very good. If a simultaneous equation is set up and solved except for the sucrose term (W1jX1), the error rate of the three basic tastes is further improved. Table 6 shows the results.

[0042]

[Table 6]

It is said that in the case of a human, the difference cannot be discriminated even if the concentration of a certain taste does not differ by at least 20% or more. From this, it can be said that the present invention can measure horse mackerel beyond the identification of horse mackerel and can be sufficiently used for horse mackerel management relying on a human tongue.

In this embodiment, a mixed solution having an intermediate concentration perceived by humans for each basic taste is used as a reference solution. However, in controlling horse mackerel such as food, a product manufactured at a certain point in time is used as a reference solution. Alternatively, the sensitivity may be determined using a taste substance that mainly contributes to the basic taste in the product. In this embodiment, a potential is selected as a measured value. However, the method of measuring a horse mackerel according to the present invention is not limited to a potential, and can be applied to a case where a change in resistance or the like is used.

[0045]

According to the present invention, the signal processing is simple while the azimuth is measured by a taste sensor using a molecular film having physicochemical characteristics close to the tongue which is a human taste organ.
A learning method with less learning data and high accuracy can be obtained.

This method is subject to the condition that the range in which it can be measured is limited. However, for example, in the control of horse mackerel such as foods, since the range of horse mackerel is often limited, the above condition does not hinder any problem. Using this method, there are differences among individuals at present, and it is susceptible to internal and external factors, and it depends on the human tongue that has limitations in terms of quantity and time. Measurements can be made easily and accurately, and the strength of horse mackerel can be expressed by objective numerical values.

[0047]

[Brief description of the drawings]

FIG. 1 is a flowchart showing an example of a horse mackerel measuring method according to the present invention.

FIGS. 2A and 2B are diagrams showing concentration characteristics for four basic tastes of each channel of the taste sensor, wherein FIG. 2A shows concentration characteristics for sweet taste (sucrose) and FIG. 2B shows concentration characteristics for bitter taste (quinine). FIG. 3C is a diagram showing a concentration characteristic for sourness (hydrochloric acid), and FIG. 4D is a diagram showing a concentration characteristic for saltyness (sodium chloride).

FIG. 3 shows a reference solution E0 and sample liquids S100 and Q10 to be measured.
The figure which shows typically the relative relationship with 0, H25, and N25.

FIG. 4 is a schematic diagram showing a lipid membrane in an expression method used in a method of designing a chemical substance.

FIG. 5 is a schematic diagram of a taste sensor, (a) is a front view,
(b) is a sectional view.

FIG. 6 is a view showing a measurement system of horse mackerel.

FIG. 7 is a schematic diagram showing a monomolecular film by an expression method used in a method of designing a chemical substance.

FIG. 8 is a flow chart showing an example of a measurement procedure used in the present invention, wherein (a) is a flow chart of the measurement procedure, and (b) is commonly used in steps 2, 4, and 5 of the measurement procedure of (a). 4 is a flowchart showing a measurement procedure performed.

FIG. 9 is a diagram schematically showing a measurement procedure used in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base material (substrate) 2 Electrode 3 Lipid film 4 Buffer layer 5 Lead wire 7 Base film 11 Solution to be measured 12 Container 13 Taste sensor array 14 Each lipid film (indicated by a black dot) 15 Reference electrode 16 Buffer layer 17 Lead wire 18 Lead wire 19 Buffer amplifier 20 Analog switch 21 A / D converter 22 Microcomputer 23 XY recorder 24 Ground potential 31 Lipid molecule group 31 ′ Lipid molecule group 32 Membrane member 33 Matrix 36 Amphiphilic molecule group or bitter substance 37 molecules of amphipathic or bitter substances

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kaoru Yamafuji 1-6-21 Kusakae, Chuo-ku, Fukuoka City, Fukuoka Prefecture (72) Inventor Kiyoshi Toko 2-83-2-2, Miwadai, Higashi-ku, Fukuoka City, Fukuoka Prefecture (72) Inventor Kenji Hayashi 2-14-18-407 Takatori, Sawara-ku, Fukuoka City, Fukuoka Prefecture (72) Inventor Hidekazu Ikezaki 5-27, Minamiazabu, Minato-ku, Tokyo Anritsu Corporation (72) Inventor Rieko Higashikubo 5-10-27 Minami-Azabu, Minato-ku, Tokyo Anritsu Corporation (72) Inventor Katsushi Sato 5-10-27 Minami-Azabu, Minato-ku, Tokyo Examiner in Anritsu Corporation Jun Koriyama (56) References JP-A-3-54446 (JP, A) JP-A-54-101397 (JP, A) JP-A-63-222248 (JP, A) JP-A-2-216445 (JP, A) JP-A-4-64053 (JP, A) 63351 (JP, A) JP-A-4-121651 (JP, A) JP-A-4-238263 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 27/416 G01N 33 / 00

Claims (1)

(57) [Claims] 1. A method for measuring a horse mackerel using a plurality of taste sensors Sj (j = 1, 2,... N) using a molecular film of an amphipathic substance or a bitter substance, comprising: Ai (i
= 1,2... M), and measuring the object to be measured with the taste sensor Sj and calculating using the sensitivity Wij to determine the strength of each basic taste Ai. Determining the value as a value converted to the concentration of the substance Bi exhibiting the taste Ai.