JP2000283953A - Freshness measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a freshness measuring method for food and drink, requiring only a short measuring time, having sensitivity not inferior compared with an organoleptic test, and capable of numerizing evaluation. SOLUTION: A taste sensor having a molecular film containing an amphipathic substance or a bitter taste substance is used for this method. A first food and drink serving as a reference for freshness is stored in a prescribed condition (S11), a taste sensor is dipped into a solution of the first food and drink stored in the prescribed condition to measure its taste so as to provide a first measured value (S12), the taste sensor is dipped into a solution of a second food and drink which is an objective for measuring freshness to measure its taste so as to provide a second measured value (S13), and the freshness of the second food and drink is found based on a difference between the first measured value and the second measured value (S14).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of measuring freshness of food and drink, and more particularly to a method of measuring freshness of food and drink using a taste sensor.

[0002]

2. Description of the Related Art The measurement of freshness of foods and drinks has been performed by chemical analysis and the like, but it is not satisfactory in terms of measurement time and measurement sensitivity, and is mainly performed by sensory tests. ing.

[0003]

However, the sensory test is
There is a problem that there are individual differences in discriminating power, difficulty in quantifying the evaluation, and poor objectivity. An object of the present invention is to solve the above-mentioned problems and reduce the measurement time.
It is an object of the present invention to provide a method for measuring the freshness of food and drink, the sensitivity of which is not inferior to that of a sensory test, and whose evaluation can be quantified.

[0004]

According to a first aspect of the present invention, there is provided a freshness measuring method comprising: a taste sensor having a molecular film containing an amphipathic substance or a bitter substance; A freshness measurement method for measuring the freshness of food and drink using, the step of storing the first food and drink as a reference of freshness under predetermined conditions, and the first food and beverage stored under the predetermined conditions Immersing the taste sensor in a solution of the food and measuring the taste to obtain a first measurement value, and immersing the taste sensor in a solution of a second food and drink whose freshness is to be measured, and measuring the taste. Measuring and obtaining a second measurement value; and determining a freshness of the second food and drink based on a difference between the first measurement value and the second measurement value.

According to a second aspect of the present invention, there is provided a freshness measuring method for measuring the freshness of food and drink using a taste sensor having a molecular film containing an amphipathic substance or a bitter substance. A step of immersing the taste sensor in a solution of one food and drink, measuring the taste thereof, obtaining a first measurement and storing the first measurement, and a second food and drink to be measured for freshness Immersing the taste sensor in a solution and measuring the taste to obtain a second measured value, and storing the second measured value based on a difference between the stored first measured value and the second measured value. Seeking freshness of food and drink.

According to a third aspect of the present invention, there is provided a freshness measuring method for measuring the freshness of food and drink using a taste sensor having a molecular film containing an amphipathic substance or a bitter substance. Before storing one food and drink under a predetermined first condition, immersing a taste sensor in a solution of the first food and drink and measuring the taste to obtain a first measurement value, and measuring freshness. Immersing a taste sensor in a solution of the second food and drink and measuring the taste thereof to obtain a second measurement value before placing the second food and drink under the second condition; and Storing the first food and drink under predetermined first conditions, and immersing a taste sensor in the solution of the first food and drink stored under the first conditions to measure the taste thereof, Obtaining a measured value; immersing the taste sensor in a solution of a second food and drink placed under the second condition; Measuring taste and obtaining a fourth measurement value, based on a difference between the difference between the first measurement value and the second measurement value, and a difference between the third measurement value and the fourth measurement value. Determining the freshness of the second food or beverage.

According to a fourth aspect of the present invention, there is provided a freshness measuring method for measuring the freshness of food and drink using a taste sensor having a molecular film containing an amphipathic substance or a bitter substance, wherein the food and drink to be measured are measured. Preparing a plurality of solutions to be measured, storing the plurality of solutions to be measured at different temperatures for a predetermined time, and immersing the taste sensor for each of the plurality of solutions to be measured stored for the predetermined time. Measuring the taste and obtaining the measured value of each of the plurality of solutions to be measured; obtaining a regression curve relating to the obtained plurality of measured values and the temperature; Obtaining a correction value of the freshness at the temperature; and adding the correction value of the freshness at the desired temperature after the desired time to the correction value of the freshness at the desired temperature obtained based on the regression curve. Multiplying the value by a value and measuring the taste by immersing a taste sensor in a solution of the first food and drink before storing the first food and drink as a reference for freshness under predetermined first conditions; Obtaining a first measured value, and immersing a taste sensor in a solution of the second food and drink before placing the second food and drink to be measured for freshness under the second condition. Measuring the taste to obtain a second measurement value, storing the first food and drink under predetermined first conditions, and a solution of the first food and drink stored under the first conditions Immersing the taste sensor in a solution of a second food and drink placed under the second condition to measure the taste and obtain a third measurement value, and immersing the taste sensor in the solution. Measuring to obtain a fourth measured value, the difference between the first measured value and the second measured value, the difference between the third measured value and the fourth measured value And a step of determining the freshness of the second food based on the difference and the correction value.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing an embodiment of the present invention, a taste sensor used in the present invention will be described. The applicant of the present application has previously filed a patent application for the invention of “taste sensor and its manufacturing method” in cooperation with others (Japanese Unexamined Patent Publication No.
54446), according to the description and the drawings, a group of so-called lipid molecules housed in a surface matrix of a certain high molecular polymer with a specific molecular arrangement has a salty, sour, bitter and sweet taste, which is called a basic taste. Thus, it was shown that the sensor showed sensitivity. In addition, it has been shown that this type of sensor can measure taste instead of taste, which is one of the human five senses.

[0009] The high molecular polymer is, for example, polyvinyl chloride (PVC), and a plasticizer such as dioctylphenylphosphonate (DOPP) and a lipid are generally used for 2:
The mixture at a weight ratio of 3: 1 was melted in tetrahydrofuran (THF), transferred to a flat-bottomed container, and kept at room temperature for 3 days on a plate to volatilize the THF, and the lipid membrane, that is, the lipids, A lipid molecular membrane housed in the matrix was obtained. The thickness of the film is about 200 μm.

FIG. 8 shows a schematic diagram of a lipidic molecular membrane in an expression method used in a method of designing a chemical substance.
The globular part of the lipid molecule 2 indicated by a circle 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. 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 3 is contained in a matrix 5 (surface structure, microstructure having planar spread) on the surface of the membrane member 4.
A part of the matrix is dissolved inside the matrix (for example, FIG. 8
2 '). Table 1 shows examples of lipids used as raw materials for molecular membranes having such structures.

[0011]

[Table 1]

A sensor probe using these lipid membranes is prepared. FIG. 9 is a cross-sectional view showing a schematic configuration in which the lipid membrane 1 obtained as described above is processed into a sensor probe 6. As the base material 7, a polyvinyl chloride cylinder having an outer shape of 8 mm, a length of 55 mm, and a thickness of 1 mm is used. Tip 7a of the cylinder 7
At an angle of about 60 degrees. The lipid membrane 1 is placed on the cut end 7a so as to cover the opening 7b with TH.
A solution obtained by dissolving PVC in F is attached as an adhesive.
A spirally wound tip of a silver wire having a diameter of 0.5 mm is inserted from above the cylinder 7 to form an electrode 8. The buffer layer 9 is filled with an electrolytic solution (a potassium chloride solution having a concentration of 3.3 mol / l) until the spiral portion of the electrode 8 is dipped in 8b.

FIG. 10 shows a taste measuring system using the sensor probe. The solution to be measured 11 is placed in a container 12 such as a beaker. The sensor probe 6 was put in the solution 11 to be measured. In this figure, one sensor probe is used. However, in the case of performing measurement using multiple channels, a plurality of sensor probes having different lipid membranes (different responses to taste) are used. Before use, potassium chloride 1mmol / l
The electrode potential was stabilized with an aqueous solution. A reference electrode 13 is prepared as an electrode for generating a potential serving as a reference for measurement, and is placed in the solution 11 to be measured. Sensor probe 6 and reference electrode 1
3 and a predetermined distance from each other. The surface of the reference electrode 13 is covered with a saturated potassium chloride solution solidified with agar as the buffer layer 14.

The electric signal from the lipid membrane 1 is guided to a buffer amplifier 17 by a lead 15 in FIG. The output of the buffer amplifier 17 is applied to an A / D converter 18. The electric signal from the reference electrode 13 is also applied to the A / D converter 18 via the lead 16 to convert the difference from the potential from the lipid membrane 1 into a digital signal. This digital signal is appropriately processed by the microcomputer 19, and X
-Displayed on the Y recorder 20.

Next, an example of a measurement procedure using the taste sensor will be described with reference to FIG. S1 The sensor potential V01 of the reference liquid is measured. In the case of batch-type measurement (measurement method in which a solution to be measured is used in a beaker or the like), the sensor potential V01 of the reference solution is measured again after the taste sensor is put in and out of the air a certain number of times. In the case of flow-type measurement (for example, a measurement method in which a solution to be measured and a reference liquid are respectively passed through a measurement pipe in which a taste sensor is set), a reference liquid is supplied to the taste sensor for a predetermined time, and then the sensor of the reference liquid is again supplied Measure the potential V01. S2 The sensor is immersed in the solution to be measured Si for a predetermined time, and the sensor potential Vi of the solution to be measured Si is measured. The predetermined time is set to make the conditions for adsorption the same for each solution Si to be measured. S3 The measurement result △ Vi = Vi-V01 of the solution to be measured Si is calculated. After that, when measuring the solution to be measured continuously, the process proceeds to S1.

The lipid is a kind of amphipathic substance,
Amphiphilic substances other than lipids shown in Table 2 and bitter substances shown in Table 3 can be used instead of lipids.

[0017]

[Table 2]

[0018]

[Table 3]

By using a taste sensor having a molecular film of an amphipathic substance or a bitter substance as described above, the freshness of food and drink can be measured.

An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a flowchart showing a freshness measuring method according to a first embodiment of the present invention, and corresponds to claim 1. S11 This is a step of storing the first food or drink serving as a reference for freshness under predetermined conditions. The first food or drink is a food or drink that is stored to provide a reference value for freshness. Therefore, the predetermined condition is a condition such that the taste of the first food and drink does not change as much as possible over time, for example, 0 ° C. to 5 ° C. if the temperature is high. S12 is a step of immersing the taste sensor in the solution of the first food and drink stored under the predetermined condition and measuring the taste to obtain a first measured value St. The first measured value St is a value serving as a reference for freshness. S13 This is a step of immersing the taste sensor in a solution of a second food or drink whose freshness is to be measured and measuring the taste to obtain a second measured value Si. S14 is a step of obtaining freshness of the second food and drink based on a difference between the first measured value and the second measured value.

Here, an experiment by the freshness measuring method according to the first embodiment will be described. The measurement target is a canned beverage that is commercially available as a sports drink. As the taste sensor, an eight-channel (1 ch to 8 ch) taste sensor using eight kinds of lipid membranes each containing a lipid shown in Table 4 was used.

[0022]

[Table 4]

The reference liquid used was a sports drink stored under the same conditions as a sports drink used as a reference for freshness.
Storage is performed in a refrigerator at a temperature of 0 ° C. The sports drinks to be measured were those placed for 1 week at a temperature of 30 ° C., those placed for 2 weeks, those placed for 1 week at a temperature of 50 ° C., and those placed for 2 weeks. There are four types.

The measuring procedure is as follows. 1) Immerse the taste sensor in a storage solution (the same as the reference solution) for approximately 10 hours. 2) Put the taste sensor in and out of the reference solution (for washing) 10 times and wash. 3) The taste sensor is immersed in the reference solution (for measurement), and after 10 seconds, the potential of the taste sensor is measured, and the measured value is set to V0. 4) Steps 2) and 3) are repeated at least twice, and the difference between the current measured value V0 and the previous measured value V0 is 0.3 mV for each measurement.
It is determined whether it is less than 0.3 mV, and if it is 0.3 mV or less (that is, if V0 is stabilized), the procedure proceeds to step 5). 5) The taste sensor is put in and taken out of the sports drink (for washing) which is stored under predetermined conditions and serves as a reference for freshness ten times, and is washed. 6) The taste sensor is immersed in a sports drink (for measurement) serving as a reference for freshness stored under predetermined conditions, and after 10 seconds, the potential St of the taste sensor is measured. 7) Put the taste sensor in and out of the sports drink (for washing) to be measured 10 times and wash it. 8) The taste sensor is immersed in the sports drink (for measurement) to be measured, and the potential Si of the taste sensor is measured after 10 seconds. 9) Repeat steps 2) to 8) a predetermined number of times.

When the measured values thus obtained were subjected to principal component analysis, the results shown in FIG. 5 were obtained. In FIG.
C1 represents the first principal component, and PC2 represents the second principal component. Under the conditions of 30 ° C. and 50 ° C., it can be seen that the points P31, P32, P51 and P32 corresponding to the freshness move away from the point P0 serving as the reference of the freshness as time passes. Further, since the direction of moving away is different, it can be seen that the quality of the deterioration is different under the condition of 30 ° C. and the condition of 50 ° C.

FIG. 2 is a flow chart showing a second embodiment of the freshness measuring method of the present invention, and corresponds to claim 2. S21 This is a step in which the taste sensor is immersed in a solution of a first food and drink serving as a reference for freshness, the taste is measured, a first measured value St is obtained, and the first measured value St is stored. The first food and drink is a food and drink for providing a value serving as a reference for freshness, and the first measured value St is a value serving as a reference for freshness. In the second embodiment, it is not necessary to store the first food and drink under predetermined conditions as in the first embodiment. S22 This is a step of immersing the taste sensor in a solution of a second food or drink whose freshness is to be measured and measuring the taste to obtain a second measured value Si. S23 is a step of obtaining the freshness of the second food or drink based on the stored difference between the first measured value and the second measured value.

FIG. 3 is a flow chart showing a third embodiment of the freshness measuring method according to the present invention, and corresponds to claim 3. S31 Before storing the first food and drink as a reference for freshness under predetermined first conditions, a taste sensor is immersed in a solution of the first food and drink to measure the taste, and the first measured value St is calculated. It is a stage to get. The first food or drink is a food or drink that is stored to provide a reference value for freshness. Therefore, the predetermined first condition is a condition in which the taste of the first food and drink does not change as much as possible even if the time has elapsed.
~ 5 ° C. The first measured value St is a value serving as a reference for freshness. S32 Before putting the second food or drink for which freshness is to be measured under the second condition, the taste sensor is immersed in the solution of the second food and drink to measure the taste, and the second measured value Sa is obtained. Is the stage of obtaining The second condition is, for example, a condition such as a temperature at which the second food or drink is transported, stored in a warehouse, or arranged in a store. S33 is a step of storing the first food and drink under predetermined conditions. S34 is a step of immersing the taste sensor in the solution of the first food and drink stored under the first condition and measuring the taste to obtain a third measured value St '. S35: immersing the taste sensor in a solution of the second food and drink placed under the second condition and measuring the taste to obtain a fourth measured value Sa '. S36 The difference Δ (Sa ′) between the difference between the first measurement value and the second measurement value and the difference between the third measurement value and the fourth measurement value.
-St ')-(Sa-St)} to determine the freshness of the second food or drink.

According to this method, it is not necessary to store the first food and beverage for all lots even when there is a difference in taste between the production lots of food and beverage that affects the measurement of freshness. It is sufficient to store the food and drink of the lot as a representative. The difference in taste between lots is Δ (Sa′−St ′) − (Sa
−St)｝ is absorbed by the calculation.

Here, an experiment by the freshness measuring method according to the third embodiment will be described. The measurement target is green tea in a can. The taste sensor is composed of eight channels (1ch to 8c) using eight kinds of lipid membranes each containing a lipid shown in Table 4 described above.
h) is a taste sensor. As a reference solution, green tea stored under the same conditions as green tea used as a reference for freshness was used. Storage is performed in a refrigerator at a temperature of 1 ° C.

The measuring procedure is as follows. 1) Immerse the taste sensor in a storage solution (the same as the reference solution) for approximately 10 hours. 2) Put the taste sensor in and out of the reference solution (for washing) 10 times and wash. 3) The taste sensor is immersed in the reference liquid (for measurement), and after 10 seconds, the potential of the taste sensor is measured, and the measured value is defined as St. 4) Steps 2) and 3) are repeated at least twice, and the difference between the current measured value St and the previous measured value St is 0.3 mV for each measurement.
It is determined whether it is less than or equal to 0.3 mV. If it is 0.3 mV or less (that is, if St is stabilized), the procedure proceeds to step 5). 5) One taste sensor for green tea (for cleaning) to be measured
Put in and out 0 times and wash. 6) The taste sensor is immersed in green tea (for measurement) to be measured, and after 10 seconds, the potential Sa of the taste sensor is measured. 7) After 30 days, the procedures 2) to 8) are repeated to obtain the measured value St 'of the reference solution and the measured value Sa' of the green tea to be measured. The green tea to be measured is placed under a condition of a temperature of 50 ° C. (second condition) for 30 days. The freshness of green tea is ｛(Sa'-
(St ')-(Sa-St)}, and this value can be used as a measure of freshness.

FIG. 4 is a flowchart showing a fourth embodiment of the freshness measuring method according to the present invention, and corresponds to claim 4. S41 is a step of preparing a plurality of solutions to be measured of food and drink to be measured. S42 is a step of storing the plurality of solutions to be measured at different temperatures for a predetermined time. S43 is a step of immersing the taste sensor in each of the plurality of solutions to be measured stored for the predetermined time to measure the taste thereof, and obtaining a measured value of each of the plurality of solutions to be measured. S44 is a step of obtaining a regression curve related to the plurality of obtained measured values and the temperature. S45 is a step of obtaining a correction value of freshness at a desired temperature based on the regression curve. S46 is a step of obtaining a correction value of the freshness at the desired temperature after the desired time by multiplying the correction value of the freshness at the desired temperature obtained based on the regression curve by the value of the ratio of the desired time and the predetermined time.

S47 Before the first food or drink serving as a reference for freshness is stored under predetermined first conditions, a taste sensor is immersed in a solution of the first food and drink to measure the taste, and the first measurement is performed. Value S
This is the stage of obtaining t. The first food or drink is a food or drink that is stored to provide a reference value for freshness. Therefore, the predetermined first condition is a condition in which the taste of the first food and drink does not change as much as possible over time, for example, a temperature of 0 ° C. to 5 ° C. The first measured value St is a value serving as a reference for freshness. S48 Before putting the second food or drink whose freshness is to be measured under the second condition, the taste sensor is immersed in the solution of the second food and drink to measure the taste, and the second measurement value is obtained. It is a stage to get. The second condition is, for example, a condition such as a temperature at which the second food or drink is transported, stored in a warehouse, or arranged in a store. S49 is a step of storing the first food and drink under predetermined conditions. S50 is a step of immersing the taste sensor in the solution of the first food and drink stored under the first condition and measuring the taste to obtain a third measured value. S51 is a step of immersing the taste sensor in a solution of the second food and drink placed under the second condition and measuring the taste to obtain a fourth measurement value. S52 Freshness of the second food and drink based on a difference between the first measurement value and the second measurement value, a difference between the third measurement value and the fourth measurement value, and the correction value Is the stage of seeking.

FIG. 6 is a diagram showing the relationship between measured values in the freshness measuring method of the present invention. In the figure, the vertical axis indicates the output of the taste sensor, and the horizontal axis indicates the number of days that have elapsed since the day serving as a reference for freshness such as production or shipment of food and drink. In addition, St is a measurement value on the day that is a reference of freshness of the first food and drink, which is a reference of freshness, Sa is a measurement value on a day that is a reference of freshness of the second food and drink for which freshness is to be measured, St 'is a measured value of the first food and drink after a lapse of a predetermined number of days, which is a reference of freshness, S
a 'is a measured value of the second food and drink of which the freshness is to be measured after a predetermined number of days, Sa''is a point after a predetermined number of days obtained by moving Sa in parallel with the line segment St St'. is there.

Referring to this figure, the above-described embodiment will be described. In the first embodiment, the first food serving as a reference for freshness is stored under predetermined conditions so that freshness is not reduced as much as possible. Therefore, the freshness at the time when the predetermined number of days has elapsed is based on the difference between the measured values Sa ′ and St ′ of the food sampled as the second food. In the second embodiment, the first food serving as a reference for freshness is stored without storing the first food or drink.
Is stored, and the freshness after a predetermined number of days has elapsed is
Measured value S of food and drink sampled as second food and drink
The difference between a 'and St is used as a guide. In this embodiment, y due to the deterioration of the first food and drink is not included in the measurement result. In the third embodiment, ｛(Sa′−St ′) − (Sa−St)
｝, That is, x is a measure of freshness. In this embodiment, even if there is a difference in taste (Sa-St) between production lots, {(Sa'-St ')-(Sa-St)} is obtained. There is no need to prepare food and drink. Also in the third embodiment, y due to the deterioration of the first food and drink is included in the measurement result. If the value of y affects the measurement of freshness, the value of y is corrected as in the following fourth embodiment.

FIG. 7 is a diagram showing a regression curve for obtaining a correction coefficient in the freshness measuring method according to the fourth embodiment of the present invention. In the figure, the vertical axis represents the output of the taste sensor, and the horizontal axis represents the storage temperature. Green tea in cans was used as food and drink. 10
Green tea stored at ℃, 20 ℃, 30 ℃, 40 ℃, 50 ℃ for 3 days was measured with a taste sensor, and a regression curve as shown in the figure was obtained from the measured values, and y at 0 ℃ and 1 ℃ was calculated. presume. For example, if the sensor output is 0.1 mV for 3 days at 1 ° C., it will be 1 mV for 30 days at 1 ° C.

[0036]

According to the present invention, the freshness of food and drink is measured using a taste sensor having a molecular film containing an amphipathic substance or a bitter substance, so that the measurement time is short and the sensitivity is low. It is possible to provide a method for measuring the freshness of food and drink, which is not inferior to the sensory test and can be evaluated numerically.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a freshness measuring method according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a freshness measuring method according to a second embodiment of the present invention.

FIG. 3 is a flowchart showing a freshness measuring method according to a third embodiment of the present invention.

FIG. 4 is a flowchart showing a freshness measuring method according to a fourth embodiment of the present invention.

FIG. 5 is a diagram showing an experimental result in the first embodiment of the freshness measuring method of the present invention.

FIG. 6 is a diagram showing a relationship between measured values in the freshness measuring method of the present invention.

FIG. 7 is a diagram showing a regression curve for obtaining a correction coefficient according to a fourth embodiment of the freshness measuring method of the present invention.

FIG. 8 is a schematic diagram showing a lipid membrane in an expression method used in the design of a chemical substance.

FIG. 9 is a cross-sectional view illustrating a schematic configuration of a sensor probe using a lipid membrane.

FIG. 10 is a diagram showing a measurement system.

FIG. 11 is a flowchart showing a measurement procedure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lipid membrane 2 Lipid molecule 3 Lipid molecule group 4 Membrane member 5 Matrix 6 Sensor probe 7 Base material (cylindrical) 8 Electrode 9 Buffer layer 10 Measurement system 11 Solution to be measured 12 Container 13 Reference electrode 14 Buffer layer 15 Lead wire 16 Lead wire 17 Buffer amplifier 18 A / D converter 19 Microcomputer 20 XY recorder 21 Shield

Continuation of front page (72) Inventor Hiroshi Komai 5-27 Minamiazabu, Minato-ku, Tokyo Anritsu Corporation

Claims (4)

[Claims] 1. A freshness measuring method for measuring freshness of a food or drink using a taste sensor having a molecular film containing an amphipathic substance or a bitter substance, wherein a first food or drink serving as a reference of freshness is determined by a predetermined method. Storing the taste sensor in the solution of the first food and drink stored under the predetermined condition and measuring the taste of the taste sensor to obtain a first measured value (S11).
12), immersing the taste sensor in a solution of a second food or drink whose freshness is to be measured and measuring the taste to obtain a second measured value (S13); and the first measured value And a step (S14) of obtaining freshness of the second food and drink based on a difference between the second measured value and the second measured value. 2. A freshness measuring method for measuring freshness of a food or drink using a taste sensor having a molecular film containing an amphipathic substance or a bitter substance, wherein a fresh food / drink solution serving as a freshness standard is used. Step of immersing the taste sensor to measure its taste, obtaining a first measured value, and storing the first measured value (S21)
And immersing the taste sensor in a solution of a second food or drink whose freshness is to be measured and measuring the taste to obtain a second measured value (S22); and storing the first measured value. Determining the freshness of the second food and drink based on a difference between the value and the second measured value (S23). 3. A freshness measuring method for measuring the freshness of food and drink using a taste sensor having a molecular film containing an amphipathic substance or a bitter substance, wherein the first food and drink as a reference of freshness is determined by a predetermined method. A step of immersing the taste sensor in the solution of the first food and drink and measuring the taste thereof to obtain a first measurement value before storing under the first condition (S31); Immersing the taste sensor in the solution of the second food and drink and measuring the taste thereof to obtain a second measured value before placing the second food and drink under the second condition (S32); Storing one food and drink under predetermined first conditions (S33); and immersing a taste sensor in the solution of the first food and drink stored under the first conditions to measure the taste thereof, and Obtaining three measurements (S
34) immersing the taste sensor in a solution of the second food and drink placed under the second condition to measure the taste and obtain a fourth measured value (S35); Obtaining a freshness of the second food and drink based on a difference between one measured value and the second measured value and a difference between the third measured value and the fourth measured value (S36). And a freshness measuring method. 4. A freshness measuring method for measuring freshness of a food or drink using a taste sensor having a molecular film containing an amphipathic substance or a bitter substance, wherein a plurality of measured solutions of the food or drink to be measured are prepared. (S41) and storing the plurality of solutions to be measured at different temperatures for a predetermined time (S41).
42) and a step of immersing the taste sensor in each of the plurality of measured solutions stored for the predetermined time and measuring the taste to obtain measured values of each of the plurality of measured solutions (S43). Obtaining a regression curve related to the plurality of measured values and the temperature (S44), obtaining a correction value of freshness at a desired temperature based on the regression curve (S45), Obtaining a correction value of the freshness at the temperature by multiplying the correction value of the freshness at the desired temperature obtained based on the regression curve by a value of the ratio of the desired time to the predetermined time (S46); Immersing a taste sensor in a solution of the first food and drink and measuring the taste thereof to obtain a first measured value before storing the first food and drink under predetermined first conditions (S47). The second drink whose freshness is to be measured Immersing the taste sensor in the solution of the second food and drink and measuring the taste to obtain a second measured value before placing the thing under the second condition (S48); Step of storing the object under predetermined first conditions (S49)
Immersing the taste sensor in the solution of the first food and drink stored under the first condition to measure the taste and obtain a third measured value (S50); Immersing the taste sensor in a second food and drink solution placed below and measuring the taste to obtain a fourth measured value (S51); the first measured value and the second measured value; Determining the freshness of the second food and drink based on the difference between the difference between the second measured value and the difference between the third measured value and the fourth measured value and the correction value (S52).
And a freshness measuring method including: