Method for measuring distribution of taste component on food surface, and method for predicting strength of taste component

Abstract

Provided is a method for measuring the distribution of a taste component on a surface of a solid food. This method for measuring the distribution of a taste component on a food surface includes a step for bringing the solid food 1 into contact with an absorber 2, and a step for measuring the distribution of the taste component of the food 1 absorbed by the absorber 2. The method can further include a step for applying, to the food 1 and the absorber 2, a pressure corresponding to a tongue pressure from when a human places the food in the mouth until the human swallows the food.

Description

Method for measuring the distribution of flavor components on the surface of food and method for predicting the intensity of flavor components

[0001] The present invention relates to a method for measuring the distribution of taste components on the surface of a solid food product, and a method for predicting the intensity of the taste components.

[0002] There is a social demand for reducing salt intake in order to prevent lifestyle-related diseases such as high blood pressure and lead healthier lives. In recent years, consumers and the market have been calling for a reduction in salt intake while maintaining the deliciousness of food, making it more important than ever to understand the relationship between the saltiness that people perceive when consuming food and the amount of salt contained in that food.

[0003] Among various types of food, when the food is liquid, the salt content of the food can be measured using a known rod-shaped salt meter such as that disclosed in Patent Document 1. When the food is liquid, the relationship between the salt content of the food and the saltiness perceived by the taste is well understood.

[0004] When food is solid, humans perceive the saltiness of the salt that dissolves from the surface of the food onto the tongue or into the saliva in the mouth, and as a result, only the salt exposed on the surface of the food is perceived as a taste.When food is solid, the relationship between the salt content of the food and the saltiness perceived as a taste is not accurately understood.

[0005] Various attempts have been made to measure the amount of salt eluted from the surface of solid foods onto the tongue or into saliva in the oral cavity, which humans perceive as salty when the food is solid. For example, in Non-Patent Document 1, food is placed in a solution simulating water or saliva, and the amount of salt eluted into the solution is measured using a salinity meter. For example, in Non-Patent Document 2, saliva is collected during eating and the amount of salt in the saliva is measured.

[0006] Japanese Utility Model Application Laid-Open Publication No. 4-110965

[0007] Loubens C et al. “Mechanistic model to understand in vivo salt release and perception during the consumption of dairy gels”, J. Agric. Food Chem. 2011, 59, 2534-2542. doi:10.1021 / jf103792bTian X, et al. “Flavor release from traditional dry-cured pork during oral processing”, Food Science and Human Wellness 2023, 12, 1, 102-110. doi.org / 10.1016 / j.fshw.2022.07.028

[0008] In solid foods, for example, by sprinkling seasoning powder on white rice, it is possible to distribute salt and other flavor components unevenly. It is empirically known that even if the total amount of salt contained in a food with uneven salt distribution is the same as that in a food with uniform salt distribution, the saltiness perceived by humans when actually ingesting the food varies. Therefore, if it were possible to understand the distribution of salt in solid foods, it would be possible to adjust the distribution of salt (in the above example, furikake) according to the desired saltiness, enabling the development of foods that meet consumer and market needs by reducing the total amount of salt contained in the food while maintaining its deliciousness.

[0009] However, none of the conventional methods for measuring the salt content of solid foods can measure the distribution of salt content. As described above, when a food is solid, people perceive the salt eluted from the food's surface as salty, and there is a need to measure the distribution of salt content on the food's surface for solid foods.

[0010] An object of the present invention is to provide a method for measuring the distribution of taste components on the surface of a solid food.

[0011] The present invention for solving the above problems includes, for example, the following aspects: (Item 1) A method for measuring the distribution of taste components on the surface of food, comprising the steps of bringing a solid food into contact with an absorbent body, and measuring the distribution of taste components in the food absorbed by the absorbent body. (Item 2) The method of Item 1, in which the time period for bringing the food into contact with the absorbent body is 20 seconds or less. (Item 3) The method of Item 1 or 2, further comprising the step of applying, to the food and the absorbent body, a pressure equivalent to the tongue pressure exerted by a person from the time the food is placed in the mouth until it is swallowed. (Item 4) The method of Item 3, in which the time period for applying the pressure is 10 seconds or less. (Item 5) The method of Item 3 or 4, in which the pressure is greater than 0 kPa and less than 18 kPa. (Item 6) The method of any one of Items 1 to 5, in which the step of measuring the distribution of taste components measures the taste components for each of a plurality of compartments of the absorbent body, the surface of which is divided into multiple compartments. (Item 7) The method according to any one of Items 1 to 5, wherein the step of measuring the distribution of taste components measures the taste components at multiple positions on the surface of the absorbent body per measurement. (Item 8) The method according to any one of Items 1 to 5, wherein the absorbent body changes reaction color depending on the concentration of the taste components, and the step of measuring the distribution of taste components measures the distribution of the taste components based on the distribution of the reaction colors in the absorbent body. (Item 9) A method for predicting the intensity of taste components of food, comprising: measuring the distribution of taste components on the surface of food by the method according to any one of Items 1 to 7, thereby obtaining multiple measurement values ​​of the taste components; and predicting the intensity of the taste component based on the maximum measurement value of the taste component determined from the obtained multiple measurement values ​​of the taste components. (Item 10) The method according to Item 9, wherein the step of predicting the intensity of the taste component predicts a sensory evaluation value of the intensity.

[0012] According to the present invention, a method for measuring the distribution of taste components on the surface of a solid food product can be provided.

[0013] 1 is a schematic diagram illustrating a distribution measurement method according to a first embodiment of the present invention. FIG. 2 is a schematic diagram illustrating a distribution measurement method according to a second embodiment of the present invention. FIG. 3 is a schematic diagram illustrating a distribution measurement method according to a third embodiment of the present invention. FIG. 4 is a schematic diagram illustrating a procedure using a conventional method. FIG. 5 is a diagram illustrating a sample of solid food prepared in Example 1. FIG. 6 is a measurement result in Example 1, and mapping data showing the distribution of salt on the sample surface obtained by an example of the present invention. FIG. 7 is a graph of the salt concentration on the sample surface calculated from the measurement results in Example 1. FIG. 8 is a diagram illustrating a sample of solid food prepared in Example 2. FIG. 9 is a measurement result in Example 2, and mapping data showing the distribution of salt on the sample surface obtained by an example of the present invention. FIG. 10 is a graph of the salt concentration on the sample surface calculated from the measurement results in Example 2. FIG. 11 is a graph showing the results of a sensory evaluation of solid food performed in Example 2. FIG. 12 is a diagram illustrating an outline of measurements performed in Example 3. FIG. 13 is a measurement result in Example 3, and mapping data showing the distribution of salt on the sample surface obtained by the distribution measurement method according to the first embodiment of the present invention. FIG. 14 is a diagram illustrating the outline and results of a sensory evaluation test performed in Example 4. FIG. 15 is a graph showing the results of a regression analysis performed in Example 4. 1 is a diagram for explaining the outline and results of a sensory evaluation test carried out in Example 5. FIG. 2 is a diagram for explaining the outline and results of measurements carried out using a surface salinity meter in Example 5.

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description and drawings, the same reference numerals will denote the same or similar components, and therefore, redundant descriptions of the same or similar components will be omitted.

[0015] [Outline of Distribution Measurement Method] The distribution measurement method according to the present invention is a method for measuring the distribution of taste components on the surface of a solid food. The distribution measurement method includes the steps of bringing the solid food into contact with an absorbent body and measuring the distribution of the taste components of the food absorbed by the absorbent body.

[0016] The target foods are solid foods. Solid foods are foods that have a fixed shape. Solid foods include inelastic foods such as crackers and biscuits, elastic foods such as bread, sponge cake, and freeze-dried tofu (frozen tofu), gel foods such as agar and jelly, and foods made by freezing liquid foods such as popsicles.

[0017] The target taste components are components related to at least one of the tastes of sweetness, saltiness, sourness, bitterness, umami, pungency, and astringency. The term "taste" as used herein includes the five basic tastes of sweetness, saltiness, sourness, bitterness, and umami, and further includes pungency and astringency in addition to these five basic tastes. Components related to sweetness include various sugars such as sucrose, fructose, and glucose. Components related to saltiness include sodium chloride. Components related to sourness include acetic acid, citric acid, and lactic acid. Components related to bitterness include caffeine. Components related to umami include glutamic acid, inosinic acid, and guanylic acid. Components related to pungency include capsaicin. Components related to astringency include tannins.

[0018] The absorbent absorbs taste components eluted from the surface of solid food. Examples of the absorbent include filter paper, gauze, sponge, and porous materials. To simulate the state from when a person puts food in their mouth until swallowing, the time the food is in contact with the absorbent is preferably within about 20 seconds, more preferably within about 10 seconds, and even more preferably within about 5 seconds. To simulate the state of the tongue surface, the absorbent is preferably moistened with a liquid. Examples of the liquid that can be used to moisten the absorbent include distilled water and artificial saliva, and any solution that does not inhibit the detection of the target taste components may be used.

[0019] There are various modes for the step of bringing the solid food into contact with the absorbent body, for example, the absorbent body and the solid food may be stacked vertically so that the solid food is placed in contact with the surface of the absorbent body, or the absorbent body and the solid food may be placed adjacent to each other horizontally so that the solid food is placed in contact with the surface of the absorbent body.

[0020] There are various modes for the step of measuring the distribution of taste components in food absorbed in an absorbent body. In this specification, three modes are exemplified as first to third embodiments described later.

[0021] The distribution measurement method according to the present invention can further include a step of applying to the food and absorbent a pressure equivalent to the tongue pressure exerted by a person from the time the food is placed in the mouth until the time the food is swallowed. This pressure equivalent to the tongue pressure exerted by a person from the time the food is placed in the mouth until the time the food is swallowed corresponds to a pressure ranging from tongue pressure at rest to tongue pressure during swallowing. The tongue pressure defined here is the pressure exerted by the tongue against the palate, and the tongue position in the oral cavity is the position when a person breathes through their nose with their mouth closed. The time for applying pressure is preferably within about 10 seconds, more preferably within about 5 seconds. Pressure may be applied to the food and absorbent after a predetermined time (e.g., about 5 seconds) has elapsed since the food was placed in contact with the absorbent, or may be applied simultaneously with the time the food is placed in contact with the absorbent. The pressure applied is preferably greater than about 0 kPa and less than 18 kPa, more preferably between about 0.2 kPa and about 0.4 kPa. In the pressure range of 0 kPa to 18 kPa, the lower limit corresponds to the average tongue pressure at rest, and the upper limit corresponds to the average tongue pressure during swallowing. For details on tongue pressure, see Thuer U, et al. "Cheek and tongue pressures in the molar areas and the atmospheric pressure in the palatal vault in young adults," Euro. J. Orthodontics 21 (1999) 299-309. doi.org / 10.1093 / ejo / 21.3.299.

[0022] The distribution measurement method according to the present invention makes it possible to measure the distribution of taste components on the surface of a solid food. Understanding the distribution of taste components in a solid food makes it possible to more appropriately adjust the distribution of taste components, thereby enabling the development of foods that maintain their deliciousness while reducing the total amount of taste components contained in the food.

[0023] Furthermore, since the distribution measurement method according to the present invention further includes a step of applying a pressure equivalent to the tongue pressure applied from the time a person places the food in their mouth until they swallow it to the food and absorbent, the distribution of taste components can be measured in a state similar to the state in which the solid food is present on the tongue at the moment when a person places the solid food in their mouth and closes their mouth.

[0024] First Embodiment FIG. 1 is a schematic diagram for explaining a distribution measurement method according to a first embodiment of the present invention.

[0025] The method for measuring the distribution of taste components on the surface of food according to the first embodiment includes the steps of bringing solid food 1 into contact with absorbent body 2, applying pressure to food 1 and absorbent body 2 that corresponds to the tongue pressure exerted by a person from the time the food is placed in the mouth until the time the food is swallowed, and measuring the distribution of taste components in food 1 absorbed into absorbent body 2, wherein the step of measuring the distribution of taste components is a method in which the taste components are measured for each of compartments 21 of absorbent body 2, the surface of which is divided into a plurality of compartments 21.

[0026] In the first embodiment, the distribution of flavor components of food 1 absorbed into absorbent body 2 is measured by measuring the flavor components in each compartment 21 of absorbent body 2, the surface of which is divided into multiple compartments 21.

[0027] In the first embodiment, the taste component to be measured is salt, and the salt is measured using a known rod-shaped salt meter 6. The absorbent body 2 is made of filter paper.

[0028] In the distribution measurement method according to the first embodiment, first, a filter paper 2 is moistened with distilled water, and a solid food 1 is placed in contact with its surface. In this embodiment, the solid food 1 is stacked vertically on the surface of the filter paper 2. Five seconds later, a weight 3 is placed on the stacked filter paper 2 and solid food 1, and pressure is applied to the filter paper 2 and solid food 1 for five seconds. In this embodiment, a flat plate 4 is sandwiched between the upper surface of the solid food 1 and the weight 3, so that pressure is applied uniformly from the lower surface of the solid food 1 to the surface of the filter paper 2. In this embodiment, the applied pressure is approximately 0.23 kPa, which is roughly equivalent to the tongue pressure exerted by a person from the time the food is placed in the mouth until it is swallowed. In this embodiment, the contact time between the filter paper 2 and the solid food 1 is approximately 10 seconds, consisting of approximately five seconds without the weight 3 and approximately five seconds after the weight 3 is placed. The time during which pressure is applied to the filter paper 2 and the solid food 1 with the weight 3 placed is approximately five seconds. When the filter paper 2 comes into contact with the solid food 1, salt is absorbed from the surface of the solid food 1 into the filter paper 2 in the contact area. As a result, the surface of the filter paper 2 reflects the distribution of salt on the surface of the solid food 1.

[0029] In this embodiment, the step of applying pressure to the food 1 and the absorbent body 2 is carried out a predetermined time (e.g., about 5 seconds) after the step of bringing the food 1 into contact with the absorbent body 2, but in other embodiments, the step of applying pressure to the food 1 and the absorbent body 2 and the step of bringing the food 1 into contact with the absorbent body 2 may be carried out simultaneously. In this case, the time for which the food 1 is brought into contact with the absorbent body 2 and the time for which pressure is applied to the food 1 and the absorbent body 2 are the same.

[0030] Next, the filter paper 2 underneath the solid food 1 is removed, and the removed filter paper 2 is cut, for example, into a grid pattern to divide the filter paper 2 into a plurality of small pieces 21. When cutting the filter paper 2 into a grid pattern, an address is assigned in advance, for example, the second row and third column. As a result, the position of each small piece 21 after cutting on the filter paper 2 is identified by the address. Each small piece 21 corresponds to a respective section 21 on the surface of the filter paper 2. Therefore, by measuring the salt content of each small piece 21, the salt distribution on the filter paper 2 can be determined. This makes it possible to measure the salt distribution on the surface of the solid food 1 in contact with the filter paper 2.

[0031] In the distribution measurement method according to the first embodiment, the salt content of each small piece 21 is measured by the following series of steps. First, the small pieces 21 are placed in a test tube 5, about 1 mL of pure water is added, and the lid of the test tube 5 is closed. The salt content that has soaked into the small pieces 21 of filter paper 2 from the solid food 1 is dissolved into the pure water in the test tube 5. Next, the test tube 5 is inverted and mixed for about 10 minutes, and then the test tube 5 is centrifuged at about 15,000 rpm. Finally, the salt content of the supernatant portion of the test tube 5 is measured using a known rod-shaped salinity meter 6.

[0032] As described above, the distribution measurement method according to the first embodiment can measure the salt distribution on the surface of solid food, thereby making it possible to reduce the total amount of salt contained in food while maintaining its deliciousness.

[0033] [Second Embodiment] The procedure of the distribution measurement method according to the second embodiment described below is the same as the procedure of the distribution measurement method according to the first embodiment unless otherwise specified, and therefore, redundant explanations will be omitted.

[0034] FIG. 2 is a schematic diagram for explaining a distribution measurement method according to a second embodiment of the present invention.

[0035] The method for measuring the distribution of taste components on the surface of food according to the second embodiment includes the steps of bringing solid food 1 into contact with absorbent body 2, applying pressure to food 1 and absorbent body 2 equivalent to the tongue pressure exerted by a person from the time the food is placed in the mouth until it is swallowed, and measuring the distribution of taste components in food 1 absorbed into absorbent body 2, wherein the step of measuring the distribution of taste components measures taste components at multiple positions on the surface of absorbent body 2 per measurement.

[0036] In the second embodiment, the distribution of the taste components of the food 1 absorbed in the absorbent body 2 is measured by measuring the taste components at a plurality of positions on the surface of the absorbent body 2 per measurement.

[0037] In the second embodiment, the taste component to be measured is salt, and the salt content at multiple positions on the surface of the filter paper 2 is measured collectively using a surface salinity meter 7 having multiple measurement electrodes. Filter paper is used for the absorbent body 2. In the first embodiment, the small pieces 21 of the filter paper 2 and pure water were placed in a test tube 5 to elute the salt that had soaked into the small pieces 21, but in the second embodiment, there is no need to cut the filter paper 2 into small pieces 21, and there is no need to use a test tube 5 for measurement.

[0038] In the method according to the second embodiment, the filter paper 2 underlying the solid food 1 is removed, and then the salt distribution of the removed filter paper 2 is measured using a surface salinity meter 7. The surface salinity meter 7 is provided with multiple measurement electrodes 71, and the surface salinity meter 7 measures the salt concentration of each measurement electrode 71. In this way, the salt distribution of the filter paper 2 is measured. For example, after placing the filter paper 2 at a predetermined measurement position on the surface salinity meter 7, the lid 72 is closed and the filter paper 2 is brought into contact with the measurement electrode 71, and measurement begins. Mapping data showing the measured salt distribution is displayed, for example, on the display unit 73 of the surface salinity meter 7.

[0039] As described above, the distribution measurement method according to the second embodiment can measure the salt distribution on the surface of solid food. The distribution measurement method according to the second embodiment can perform measurements more easily and conveniently than the distribution measurement method according to the first embodiment.

[0040] [Third Embodiment] The procedure of the distribution measurement method according to the third embodiment described below is the same as the procedure of the distribution measurement method according to the first embodiment unless otherwise specified, and therefore, redundant explanations will be omitted.

[0041] FIG. 3 is a schematic diagram for explaining a distribution measurement method according to a third embodiment of the present invention.

[0042] A method for measuring the distribution of taste components on the surface of food according to the third embodiment includes the steps of bringing solid food 1 into contact with absorbent body 2, applying pressure to food 1 and absorbent body 2 equivalent to the tongue pressure exerted by a person from the time the food is placed in the mouth until it is swallowed, and measuring the distribution of taste components in food 1 absorbed into absorbent body 2, wherein absorbent body 2 changes reaction color depending on the concentration of the taste components, and the step of measuring the distribution of taste components measures the distribution of taste components based on the distribution of reaction colors in absorbent body 2.

[0043] In the third embodiment, an absorbent 2 whose reaction color changes depending on the concentration of the flavor components is used, and the distribution of the flavor components of food 1 absorbed into the absorbent 2 is measured based on the distribution of reaction colors in the absorbent 2.

[0044] In the method according to the third embodiment, the taste component to be measured is acid, and a plurality of pH test papers joined together in a flat shape is used as the absorbent 2. pH test papers are generally made by impregnating filter paper with a pH indicator and drying it. When the pH test paper 2 comes into contact with the solid food 1, acid is absorbed from the surface of the solid food 1 into the pH test paper 2 in the contact area. As a result, the surface of the pH test paper 2 reflects the distribution of acid on the surface of the solid food 1.

[0045] In the method according to the third embodiment, after removing the pH test paper 2 from under the solid food 1, the distribution of acid on the surface of the solid food 1 is determined based on the change in the reaction color of the pH indicator on the surface of the pH test paper 2. For example, by comparing the pH test paper 2 with a color sample, it is possible to determine that the surface of the solid food 1 corresponding to a position 23a on the surface of the pH test paper 2 where the reaction color is red, for example, is strongly sour. Similarly, it is possible to determine that the surface of the solid food 1 corresponding to a position 23b where the reaction color is yellow, for example, is moderately sour, and it is possible to determine that the surface of the solid food 1 corresponding to a position 23c where the reaction color is green, for example, is mildly sour (neutral). This allows the distribution of acid absorbed by the pH test paper 2 on the surface of the solid food 1 to be measured.

[0046] As described above, the distribution measurement method according to the third embodiment makes it possible to measure the distribution of acids on the surface of solid food.

[0047] In the third embodiment, multiple pH test papers are joined together in a flat shape, but multiple small pieces of pH test paper may be arranged in a grid pattern and joined together in a flat shape, which improves the accuracy of identifying the position between the pH test paper 2 and the solid food 1.

[0048] [Intensity Prediction Method] As described above, the distribution measurement method according to the present invention makes it possible to measure the distribution of taste components on the surface of a solid food. By measuring the distribution of taste components in this way, it is possible to obtain multiple measured values ​​of the taste components. For example, in the distribution measurement method according to the first embodiment, taste components are measured for each of the compartments 21 of an absorbent body 2 whose surface is divided into multiple compartments 21. Furthermore, in the distribution measurement method according to the second embodiment, taste components are measured at multiple positions on the surface of the absorbent body 2 per measurement.

[0049] The method for predicting the intensity of taste components in food according to the present invention predicts the intensity of the taste components based on the maximum measured value of the taste components. The maximum measured value of the taste components is determined from multiple measured values ​​of the taste components obtained through the distribution measurement method according to the present invention. That is, the intensity prediction method according to the present invention includes the steps of: measuring the distribution of the taste components on the surface of the food to obtain multiple measured values ​​of the taste components; and predicting the intensity of the taste components based on the maximum measured value of the taste components determined from the multiple measured values ​​of the taste components obtained. Preferably, the intensity of the taste components is a sensory evaluation value of the taste components, and the step of predicting the intensity of the taste components predicts the sensory evaluation value of the intensity of the taste components. Preferably, the taste components are salt, and the measured value of the taste components is the amount of salt per unit area on the surface of the food.

[0050] [Other Embodiments] Although the present invention has been described above with reference to specific embodiments, the present invention is not limited to the above-described embodiments.

[0051] In the above-described embodiments, the target taste is salty or sour, and the target taste component is salt or acid, but the target taste and taste component are not limited to these. Just as in the first embodiment, where salt is measured using a known rod-shaped salt meter, and in the third embodiment, where acid is measured using pH test paper 2, the distribution measurement method according to the present invention can be applied to various tastes and taste components other than salt and acid, as long as these taste components can be detected, and the distribution of various taste components on the surface of solid foods can be measured.

[0052] For example, in the first embodiment, instead of a rod-shaped salt meter, a portable sugar-acidity meter, such as one for citrus fruits, can be used to measure the distribution of sweetness and sourness on the surface of solid food 1. Furthermore, in the third embodiment, instead of a pH test paper 2 that changes color in response to acid concentration, an absorbent 2 that changes color in response to sugar or sodium chloride concentration can be used to measure the distribution of sweetness and saltiness on the surface of solid food 1. The absorbent 2 that changes color in response to sugar concentration can be, for example, a test paper for urine glucose testing that reacts with glucose or a sucrose test paper that reacts with sucrose. For example, the sucrose test paper can be paper impregnated with sucrose decomposing enzyme (invertase), glucose oxidase, hydrogen peroxide decomposing enzyme (peroxidase), and a color developer (aminoantipyrine, dimethylaniline). The absorbent 2 that changes color in response to sodium chloride concentration can be, for example, a test paper for measuring salt concentration. Test paper for measuring salt concentration may be, for example, paper impregnated with a dye (2,7-dichlorofluorescein: HF1) and silver nitrate.

[0053] In the above-described embodiment, a pressure equivalent to the tongue pressure applied by a person from the time the food is placed in the mouth until the time the food is swallowed is applied to the food 1 and the absorbent body 2, but this pressure application process is an optional process and can be omitted in other embodiments.

[0054] Examples of the present invention will be described below to clarify the features of the present invention. In the examples below, the salt concentration in the solution is expressed in weight percent [%], and the salt concentration on the surface is expressed in the amount of salt per unit area [μg / cm ２ ] is used.

[0055] In Example 1, a comparison was made between the method of the present invention and a conventional method for measuring the distribution of taste components. In both the method of the present invention and the conventional method, a solid food 1 was stacked vertically on the surface of a filter paper 2, and five seconds later, a weight 3 was placed on the stacked filter paper 2 and solid food 1, and pressure was applied to the filter paper 2 and solid food 1 for five seconds. The applied pressure was 0.23 kPa.

[0056] In the example of the present invention for measuring the distribution, the distribution measurement method according to the second embodiment was adopted, which uses a surface salinity meter 7 having multiple measurement electrodes. The surface salinity meter 7 measured the salt concentrations [μg / cm] at multiple positions on the surface of the filter paper 2. ２ ] were measured all at once, and the average value of the salt concentration on the surface of the filter paper 2, the maximum value of the salt concentration on the surface of the filter paper 2, and mapping data showing the distribution of the measured salt were obtained. The surface salinity meter 7 used was an Elcometer 130 SSP salt concentration meter manufactured by Elcometer Limited in the UK. Note that since the solid food 1 is not in contact with the entire surface of the filter paper 2, the salt concentration value on the surface of the filter paper 2 was obtained by multiplying the measured value of the salt concentration by the surface salinity meter 7 by the following coefficient a. Coefficient a = total area of ​​the filter paper 2 / area in contact between the filter paper 2 and the solid food 1

[0057] As a comparative example of the conventional method in which the distribution was not measured, a method was adopted in which salt was dissolved from the entire filter paper 2 and the salt content of the entire filter paper 2 was measured. The procedure for the conventional method is shown in Figure 4. From the salt content of the entire filter paper 2 obtained by measurement, the amount of salt per unit area [μg / cm ２ ] was calculated and used as the salt concentration on the surface of the filter paper 2. The calculation method is as follows: 1. Calculate the amount of salt on the entire filter paper (only weight, not concentration). 2. Calculate the area where the filter paper and the solid food were in contact (for example, 3 x 3 = 9 cm ２ 3. The amount of salt on the entire filter paper divided by the contact area is the amount of surface salt.

[0058] The solid food samples prepared in Example 1 are shown in Figure 5. In Example 1, agar was used as the solid food sample, and two types of agar were prepared: agar with a uniform salt concentration of 1 wt% (hereinafter referred to as Sample A) shown in Figure 5(A) and agar with a non-uniform salt concentration (hereinafter referred to as Sample B) shown in Figure 5(B). For both Samples A and B, the average salt concentration of the entire sample was 1 wt%, and the total amount of salt contained in the sample was the same. Each sample was prepared by combining four rectangular agar blocks measuring 1.5 cm x 1.5 cm x 1 cm, as shown in Figure 5. The block designated by reference numeral 11a had a salt concentration of 1 wt%, and the block designated by reference numeral 11b had a salt concentration of 4 wt%. The block designated by reference numeral 11c was a salt-free block with a salt concentration of 0 wt%.

[0059] 6 shows mapping data representing the distribution of salt on the sample surface obtained by the embodiment of the present invention as a measurement result in Example 1. (A) is data for sample A, which has a uniform salt concentration, and (B) is data for sample B, which has a non-uniform salt concentration.

[0060] Consider the data shown in Figure 6. As shown numerically in Figure 6, the average salt concentration on the surface of the entire sample was approximately 55 to 59 μg / cm for both Sample A and Sample B. ２ The maximum surface salt concentration was approximately the same for Sample A and Sample B. In contrast, when comparing the maximum surface salt concentration, Sample B, which has a non-uniform salt concentration, had a maximum of 80.4 μg / cm, which is about 1.8 times that of Sample A, which has a uniform salt concentration. ２ High values ​​of were measured in spots.

[0061] Therefore, from the measurement results for sample B, which has a non-uniform salt concentration, it was confirmed that the embodiment of the present invention was able to measure the distribution of salt on the surface of agar, which is a solid food.

[0062] 7 is a graph of the salt concentration on the surface of the sample calculated from the measurement results in Example 1. (A) is a graph of the average salt concentration on the surface, and (B) is a graph of the maximum salt concentration on the surface. The unit of salt concentration in the graph is μg / cm２ ], which corresponds to the amount of salt per unit area. In Fig. 7, the data relating to the examples of the present invention is the same as the mapping data shown in Fig. 6. (B) is a graph showing the maximum values ​​of the surface salt concentrations shown numerically in the mapping data of Fig. 6. Table 1 shows the numerical values ​​relating to the various conditions used to calculate the surface salt concentrations shown in the graph of Fig. 7 for the comparative example and the examples.

[0063]

[0064] Considering the data shown in Figure 7(A), for both the example of the present invention in which distribution was measured and the comparative example in which distribution was not measured, no significant difference was confirmed in the average surface salt concentration obtained by measurement between sample A, which had a uniform salt concentration, and sample B, which had a non-uniform salt concentration.

[0065] In Example 2, a solid food sample different from that in Example 1 was prepared, and a comparison was made between the method of the present invention and the conventional method in the same manner as in Example 1. Furthermore, in Example 2, a sensory evaluation was performed on the prepared solid food sample. Example 2 was the same as Example 1, except that a different solid food sample was prepared and that a sensory evaluation was performed.

[0066] The solid food samples prepared in Example 2 are shown in Figure 8. In Example 2, sandwich bread was used as the solid food sample. Two types of bread were prepared: one with a uniform surface salt concentration of 1 wt% (shown in Figure 8(A) as Sample C) and one with a non-uniform surface salt concentration (shown in Figure 8(B) as Sample D). Both Samples C and D had an average salt concentration of 1 wt% throughout the sample, and the total amount of salt contained in each sample was the same. Each sample was prepared using small pieces of bread measuring 3 cm x 3 cm and the same thickness. Sample C was prepared by dropping 100 μL of 1 wt% sodium chloride solution onto each of the four areas of the bread surface indicated by the reference symbol 12a, as shown in Figure 8(A). Sample D was prepared by dropping 100 μL of a 4 wt % sodium chloride solution onto one area of ​​the surface of the bread indicated by reference symbol 12b, as shown in FIG. 8(B), and dropping 100 μL of pure water onto the remaining three areas of the surface of the bread indicated by reference symbol 12c.

[0067] 9 shows mapping data representing the distribution of salt on the sample surface obtained by the embodiment of the present invention as a measurement result in Example 2. (A) is data for sample C, which has a uniform salt concentration, and (B) is data for sample D, which has a non-uniform salt concentration.

[0068] Consider the data shown in Figure 9. Similar to the data for Example 1 shown in Figure 6, the data for Example 2 shown in Figure 9 also showed a similar tendency. The average surface salt concentration of the entire sample was similar for Sample C and Sample D. Comparing the maximum surface salt concentration, Sample D, which has an uneven salt concentration, had a salt concentration of 76.5 µg / cm, which is about 1.6 times that of Sample C, which has a uniform salt concentration. ２ High values ​​of were measured in spots.

[0069] Therefore, from the measurement results for sample D, which has a non-uniform salt concentration, it was confirmed that the embodiment of the present invention was able to measure the distribution of salt on the surface of bread, which is a solid food.

[0070] 10 is a graph showing the salt concentration on the surface of the sample calculated from the measurement results in Example 2. (A) is a graph showing the average value of the salt concentration on the surface, and (B) is a graph showing the maximum value of the salt concentration on the surface. The unit of salt concentration in the graph is μg / cm. ２ ], which corresponds to the amount of salt per unit area. In Fig. 10, the data relating to the examples of the present invention is the same as the mapping data shown in Fig. 9. (B) is a graph showing the maximum values ​​of the surface salt concentrations shown numerically in the mapping data of Fig. 9. Table 2 shows the numerical values ​​relating to the various conditions used to calculate the surface salt concentrations shown in the graph of Fig. 10 for the comparative example and the examples.

[0071]

[0072] Consider the data shown in Fig. 10(A). Similar trends were observed for the data in Example 2 shown in Fig. 10(A), as with the data in Example 1 shown in Fig. 7(A). In both the Example of the present invention in which distribution was measured and the Comparative Example in which distribution was not measured, no significant difference was observed in the average surface salt concentration values ​​obtained by measurement between Sample C, which had a uniform salt concentration, and Sample D, which had a non-uniform salt concentration.

[0073] FIG. 11 is a graph showing the results of the sensory evaluation of the solid foods carried out in Example 2.

[0074] A sensory evaluation of the solid food samples was conducted for each of Samples C and D. The sensory evaluation was conducted by actually eating the sample, i.e., the evaluator opened their mouth, placed the sample on their tongue, and then closed their mouth after 5 seconds. After 5 seconds had passed, the evaluator rated the strength of the saltiness they felt on a 5-point scale.

[0075] Consider the graph shown in Figure 11. Although the total amount of salt contained in the samples was the same for both Samples C and D, the sensory evaluation confirmed that Sample D, which had a non-uniform salt concentration, tasted saltier than Sample C, which had a uniform salt concentration, as shown in the graph in Figure 11. Furthermore, a comparison of the graph in Figure 11 with the graph in Figure 10(B) reveals that the sensory evaluation of the taste intensity of solid foods is based on the concentration [μg / cm ] of the taste components on the surface of the solid food, as measured using a surface salinity meter. ２ ] is likely to correlate with the maximum value of

[0076] In Example 3, the distribution of taste components was actually measured by the distribution measurement method according to the first embodiment. An outline of the measurement performed in Example 3 is shown in FIG.

[0077] The same agar as in Example 1 was used for the solid food samples, and two types of agar were prepared: agar with a uniform salt concentration of 1 wt % as shown in Figure 12(A) (hereinafter referred to as Sample E), and agar with a non-uniform salt concentration as shown in Figure 12(B) (hereinafter referred to as Sample F). Sample E is the same as Sample A prepared in Example 1. Sample F differs from Sample B prepared in Example 1 only in the position of the block indicated by reference symbol 11b (with a salt concentration of 4 wt %).

[0078] Addresses were assigned to the filter paper 2 in the arrangement shown in Figure 12. For each of Samples E and F, solid food 1 was stacked vertically on the surface of the filter paper 2, as in Example 1. Five seconds later, a weight 3 was placed on the stacked filter paper 2 and solid food 1, and pressure was applied to the filter paper 2 and solid food 1 for five seconds. The pressure applied was 0.23 kPa. The filter paper 2 underneath the solid food 1 was removed, and the removed filter paper 2 was cut into a grid pattern to divide the filter paper 2 into multiple small pieces 21. The salt content of each of the multiple small pieces 21 was measured. The salt content measurement was performed following the series of procedures exemplified in the first embodiment. Figure 13 shows the distribution (mapping data) of salt concentration on the sample surface measured for each of Samples E and F. Table 3 shows the values ​​for the various conditions used to calculate the surface salt concentration shown in the mapping data of Figure 13.

[0079]

[0080] Consider the mapping data shown in Figure 13. For sample E, which has a uniform salt concentration, the measured surface salt concentration was roughly uniform at the surface positions corresponding to addresses E1 to E9. This suggests that the surface of the filter paper 2 reflects the distribution of salt on the surface of sample E. For sample F, which has a non-uniform salt concentration, the measured surface salt concentration was spot-high at the surface position corresponding to address F9. A 4 wt% block with a higher salt concentration than the others was placed at the surface position of sample F corresponding to address F9. This suggests that the surface of the filter paper 2 reflects the distribution of salt on the surface of sample F. From the above, it was confirmed that the distribution measurement method according to the first embodiment of the present invention can actually measure the distribution of taste components.

[0081] In Example 4, a detailed study was conducted on a method for predicting the intensity of a taste component of a food based on the maximum measured value of the taste component of the food. The following two items (tests and analyses) were carried out in the study.

[0082] First, a sensory evaluation test was conducted to confirm whether there is a difference in the saltiness perceived by humans even when the salt content is the same. The purpose of this sensory evaluation test was to reconfirm what has been empirically known so far.

[0083] 14A and 14B are diagrams illustrating the outline and results of the sensory evaluation test conducted in Example 4. (A) is a diagram illustrating the outline of the sensory evaluation test. (B) is a graph showing the results of the sensory evaluation test.

[0084] As shown on the left side of Figure 14(A), two filter papers 14u (14) with a uniform salt distribution and filter papers 14a, 14b, and 14c (14) with non-uniform salt distribution were prepared as samples for the sensory evaluation test. The filter paper 14u with a uniform salt distribution was prepared by uniformly dispensing 30 μL of saline solution with a salt concentration of 1 wt% over the entire area. The filter papers 14a, 14b, and 14c with non-uniform salt distribution were prepared in three types: the center, right, and left areas of the filter paper where salt was localized. The filter papers 14a, 14b, and 14c with non-uniform salt distribution were prepared by dispensing 10 μL of saline solution with a salt concentration of 3 wt% over a localized area, and dispensing 10 μL of distilled water over the remaining areas. A commercially available coffee filter was used for the filter paper 14 (1 cm x 2.4 cm). Next, as shown on the right side of Fig. 14(A), an evaluator placed each of the four types of filter paper 14 prepared on the tip of his / her tongue 15, and rated the saltiness intensity perceived by the evaluator on a scale of 1 to 10. The results of the sensory evaluation test are shown in Fig. 14(B) and Table 4. As shown in Fig. 14(B), it was confirmed that when the distribution of salt is localized (uneven) on the tip of the tongue 15, the saltiness is perceived as being stronger.

[0085]

[0086] Second, the correlation between the maximum measured salt content and the saltiness perceived by humans (sensory evaluation value) was determined by regression analysis. By determining a relational expression between the maximum measured salt content and saltiness in advance by regression analysis, it is possible to predict the saltiness perceived by humans from the maximum measured salt content based on this relational expression.

[0087] The data for the regression equation were obtained as follows. First, 30 μL of saline solution with salinity concentrations of 1, 2, and 3% by weight was uniformly dispensed over the entire surface of each filter paper (14u1, 14u2, and 14u3). Next, for each of the prepared filter papers (14u1, 14u2, and 14u3), a human sensory evaluation of saltiness (on a 10-point scale) and instrumental measurement of maximum salinity were performed. The maximum salinity was measured using an Elcometer 130 SSP salinity meter manufactured by Elcometer Limited, UK. The Elcometer 130 SSP salinity meter can be used as a surface salinity meter, measuring the amount of salt per unit area at each location on the surface of a food product using multiple measurement electrodes.

[0088] 15 is a graph showing the results of the regression analysis performed in Example 4. The salinity [μg / cm 3 ] measured by the surface salinity meter determined by the regression analysis. ２ The relationship between the maximum value of [salt content] and the saltiness perceived by humans (sensory evaluation value on a 10-point scale) was as follows: Saltiness = 0.0266 × maximum saltiness + 0.2403

[0089] In Example 5, we verified whether it is possible to measure the difference in taste intensity perceived by humans with or without tongue pressure using an instrument. The verification was carried out by comparing the difference in taste intensity with or without pressure between the results of a human sensory evaluation test and the results of measurements using a surface salinity meter. In the human sensory evaluation test, the presence or absence of tongue pressure was defined as follows: when the evaluator opened their mouth, it was considered that there was no tongue pressure, and when the evaluator closed their mouth, it was considered that there was tongue pressure.

[0090] 16A and 16B are diagrams illustrating the outline and results of the sensory evaluation test conducted in Example 5. (A) is a diagram illustrating the outline of the sensory evaluation test. (B) is a graph showing the results of the sensory evaluation test.

[0091] As shown on the left side of Figure 16(A), a small piece 16 of bread was prepared as a sample for the sensory evaluation test, onto which 300 μL of saline solution with a salt concentration of 1% by weight had been dropped. The small piece 16 was a cube measuring 1 cm x 1 cm x 1 cm. Next, as shown on the right side of Figure 16(A), four evaluators each placed the prepared sample 16 on the tip of their tongue 15 and rated the saltiness intensity perceived by the evaluators on a 10-point scale. The evaluation was conducted both with and without tongue pressure. When applying tongue pressure, the evaluators were instructed to "close their mouths and press the sample against the roof of their mouths with their tongues for three seconds. During this time, note the strongest perceived saltiness intensity. Press the sample against the roof of their mouths enough that moisture is felt to seep out of the bread." The results of the sensory evaluation test are shown in Figure 16(B) and Table 5.

[0092]

[0093] 17A and 17B are diagrams illustrating the outline and results of measurements performed using a surface salinity meter in Example 5. (A) is a diagram illustrating the outline of measurements using a surface salinity meter. (B) is a graph showing the results of measurements using a surface salinity meter.

[0094] As shown on the left side of Figure 17(A), a sample identical to the sample (small piece of bread 16 dripped with saline solution) used in the human sensory evaluation test described with reference to Figure 16 was prepared. Pressure was then applied to the sample 16 according to the distribution measurement method of the second embodiment of the present invention described with reference to Figure 2. First, filter paper 17 was moistened with distilled water, and the sample 16 was placed in contact with its surface. Five seconds later, a flat plate 4 and a weight 3 weighing 200 g were placed on the stacked filter paper 17 and sample 16, and pressure was applied for five seconds to allow the exuded saline solution to be absorbed into the filter paper 17. As shown on the right side of Figure 17(A), the filter paper 17 that had absorbed the saline solution was placed on a surface salinity meter 7 equipped with multiple measurement electrodes. The salinity concentration was measured at each measurement electrode, thereby measuring the salinity at multiple positions. Measurements were performed both with and without pressure applied to the sample 16. The measurement results are shown in Figure 17(B) and Table 6. The salinity concentration values ​​shown in FIG. 17(B) and Table 6 are the maximum values ​​among the multiple salinity concentrations measured by the multiple measurement electrodes.

[0095]

[0096] With reference to Figures 16(B) and 17(B), we consider whether it is possible to measure the difference in taste intensity due to the presence or absence of tongue pressure using an instrument. The graph in Figure 16(B), which shows the results of a sensory evaluation test conducted by humans, was compared with the graph in Figure 17(B), which shows the results of measurements using a surface salinity meter. As shown in the graph in Figure 16(B), when tongue pressure was applied, the humans perceived the saltiness as stronger. As shown in the graph in Figure 17(B), when pressure was applied, the measured salt concentration value using the surface salinity meter also increased. With respect to the presence or absence of pressure applied to the sample, the results of the sensory evaluation test conducted by humans and the results of the maximum salt concentration measurement using the surface salinity meter showed the same trend. This demonstrates that it is possible to measure the difference in taste intensity perceived by humans due to the presence or absence of tongue pressure using an instrument.

[0097] REFERENCE SIGNS LIST 1 Solid food 2 Absorbent (filter paper, pH test paper) 3 Weight 4 Flat plate 5 Test tube 6 Salt meter 7 Surface salinity meter 21 Absorbent piece (section) 71 Measuring electrode 72 Lid 73 Display unit

Claims

1. A method for measuring the distribution of taste components on a surface of a food, comprising the steps of: bringing a solid food into contact with an absorbent body; and measuring the distribution of taste components of the food absorbed by the absorbent body.

2. The method of claim 1, wherein the food is contacted with the absorbent for 20 seconds or less.

3. The method according to claim 1, further comprising the step of applying a pressure to said food and said absorbent body equivalent to the tongue pressure exerted by a human being when he or she places food in the mouth and swallows it.

4. The method of claim 3, wherein the pressure is applied for no more than 10 seconds.

5. The method of claim 3, wherein the pressure is in the range of greater than 0 kPa to less than 18 kPa.

6. A method according to any one of claims 1 to 5, wherein the step of measuring the distribution of the taste components comprises measuring the taste components for each of a plurality of compartments of the absorbent body, the surface of which is divided into a plurality of compartments.

7. A method according to any one of claims 1 to 5, wherein the step of measuring the distribution of the taste components comprises measuring the taste components at multiple positions on the surface of the absorbent body per measurement.

8. A method according to any one of claims 1 to 5, wherein the absorbent changes reaction color depending on the concentration of the taste component, and the process of measuring the distribution of the taste component measures the distribution of the taste component based on the distribution of the reaction color in the absorbent.

9. A method for predicting the intensity of taste components of a food, comprising: a step of obtaining a plurality of measurement values ​​of the taste components by measuring the distribution of the taste components on the surface of the food by the method according to claim 1; and a step of predicting the intensity of the taste component based on the maximum value of the measurement values ​​of the taste components, which is determined from the plurality of obtained measurement values ​​of the taste components.

10. The method according to claim 9, wherein the step of predicting the intensity of a taste component predicts a sensory evaluation value of the intensity.

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