JP6940124B2 - Method of estimating the time when foreign matter is mixed - Google Patents

Description

The present invention relates to a method for determining the mixing timing of a foreign substance mixed in a food based on the degree of penetration of an organic substance as a food component into the foreign substance measured by an infrared absorption analysis method.

Food is taken into the body, and of course, its safety must be ensured. Therefore, in quality control of food production, for example, matters that may cause foreign matter contamination must be thoroughly eliminated.

In order to thoroughly implement such quality control, it is necessary to accurately grasp the actual state of foreign matter contamination. Therefore, first, the foreign matter mixed in the food is mixed in the manufacturing process, or after the product is opened. It is important to verify whether it is mixed or when the foreign matter is mixed.

Therefore, a method for determining the time when a foreign substance such as hair or plastic is mixed has been developed and studied (Non-Patent Documents 1 and 2), and the present inventors have also developed and studied a method for determining the time when a foreign substance such as hair or plastic is mixed in the foreign substance. We have developed and reported a method for analyzing the degree of penetration of an inorganic compound (for example, sodium chloride) in a food component and determining the time when a foreign substance is mixed based on the result (Patent Document 1).

Japanese Unexamined Patent Publication No. 2005-83804

Gen Sato, "Mixed Hair Identification Method", published by Science Forum Co., Ltd., 2000 Convertec, November 2002, Published by Processing Technology Research Association Co., Ltd., "Using the phase shift from smectic type to α crystal, which shows the history of retort heat treatment by DSC analysis of CPP film" (Ajinomoto Co., Inc. Production Technology Development Center)

The method for determining the time of contamination of a foreign substance described in Patent Document 1 is the permeation position (permeation status) and amount (permeation amount) of a food component such as sodium chloride into the foreign substance mixed in the food (that is, the permeation amount). , However, the present inventors confirm that a large amount of inorganic compounds such as sodium chloride in the food component immediately permeate deep inside the mixed foreign matter, and the change in the permeation degree is confirmed. It has been found that it may not be possible, and in that case, it may be difficult to accurately determine the time when the foreign matter is mixed in the mixed foreign matter several days after the product is opened.

Therefore, an object of the present invention is to provide a new discriminating method capable of accurately determining the mixing time even if the mixed foreign matter is obtained after a while after opening the product.

As a result of diligent studies to solve the above problems, the present inventors did not immediately permeate the organic substances having a molecular weight of about 50 to 700 in the food component deep inside the foreign matter mixed after opening the product, and the degree of permeation thereof. It was found that the change can be confirmed over a long span of days by the infrared absorption analysis method. Then, by using the degree of penetration of the organic substance as an index, it was found that even if the mixed foreign matter is obtained several days after the product is opened, the mixing time can be accurately determined.

The present invention is based on these findings and includes the following inventions.
[1] A method for determining the time when a foreign substance mixed in a food is mixed, and the degree of penetration of an organic substance having a molecular weight of 50 to 700 in the food component into the mixed foreign substance is analyzed by an infrared absorption analysis method. , The above method, which comprises determining the time of contamination of a foreign substance based on the analysis result.
[2] When the food is a food that has been heat-treated in the manufacturing process,
A part of the mixed foreign matter is heat-treated under the same conditions as the heat treatment in the manufacturing process, and the degree of penetration of the organic substance into the heat-treated mixed foreign matter and the non-heat-treated mixed foreign matter into the mixed foreign matter. The method of [1], which comprises analyzing and comparing the degree of penetration by an infrared absorption analysis method.
[3] When the food is a food that has not been heat-treated in the manufacturing process
A part of the mixed foreign matter is mixed in the food for a certain period of time to carry out a preservation treatment for permeating the organic matter into the mixed foreign matter, and then the degree of penetration of the organic matter into the mixed foreign matter subjected to the preservation treatment and the said. The method of [1], which comprises analyzing and comparing the degree of penetration of the organic substance into the mixed foreign matter which has not been subjected to the storage treatment by an infrared absorption analysis method.
[4] The method according to any one of [1] to [3], wherein the organic substance is selected from the group consisting of glucose, lactose, and lactic acid.
[5] The method according to any one of [1] to [4], wherein the mixed foreign matter is hair.

According to the present invention, it is possible to more accurately determine whether the foreign matter mixed in the food is mixed in the manufacturing process or after the product is opened, and the mixing time thereof.

FIG. 1 is a photographic diagram showing the degree of glucose penetration of hair mixed in a non-heat-treated and heat-treated sample (glucose water) after each storage period (0 days, 1 day, 7 days) at 25 ° C. .. FIG. 2 shows the degree of glucose penetration of hair mixed in non-heat-treated and heat-treated samples (6%, 30%, or 60% glucose water) after each storage period (0 days, 7 days) at 25 ° C. It is a photographic figure which shows. FIG. 3 shows the degree of lactose penetration in hair mixed with non-heat-treated and heat-treated samples (6% or 30% lactose water) after each storage period (0 days, 7 days) at 25 ° C or 4 ° C. It is a photographic figure which shows. FIG. 4 is a photographic diagram showing the degree of penetration of lactic acid in hair mixed in a non-heat-treated and heat-treated sample (lactic acid water) after each storage period (0 days, 7 days) at 25 ° C. or 4 ° C. .. FIG. 5 is a photographic diagram showing the degree of permeation of sugar in hair mixed in a non-heat-treated and heat-treated sample (orange juice) after each storage period (0 days, 7 days) at 4 ° C. FIG. 6 is a photographic diagram showing the degree of permeation of sugar in hair mixed in a non-heat-treated and heat-treated sample (yokan) after each storage period (0 days, 7 days) at 4 ° C. FIG. 7 is a photographic diagram showing the degree of permeation of sugar in hair mixed in a non-heat-treated and heat-treated sample (blueberry jam) after each storage period (0 days, 7 days) at 4 ° C.

The present invention relates to a method for determining when a foreign substance mixed in food is mixed.
In the present invention, the "food" means various processed foods provided in restaurants and the like, which can be distributed at room temperature, frozen, chilled, and the like. Processed foods include, for example, retort products such as curry, stew, soup and sauce, roux products such as curry and stew, frozen foods, various spice products such as kneaded wasabi, kneaded sardines and mustards, seasonings such as mayonnaise and dressings. Products, dairy products such as yogurt, butter, cheese and ice cream, dessert products such as jelly and pudding, confectionery products such as chocolate and cookies, and beverage products such as tea, coffee and fruit beverages can be mentioned. Not limited to.

In the present invention, the "foreign substance" includes any substance that can be mixed in the food, but the substance that the organic substance in the food component can permeate is the target, and the organic substance in the food component such as metal does not permeate. Substances are not included in the "foreign matter" in the present invention. Examples of the "foreign substance" in the present invention include human hair such as hair, hair such as animal hair, nails, paper, cotton products (threads, cloth), wood chips, plant raw materials, stems, roots, and animal raw materials. Examples include, but are not limited to, bone fragments, threads, ropes, strings, insects, plastics and rubbers.

According to the present invention, it is possible to determine when the above-mentioned foreign matter is mixed in the food, that is, whether it is in the manufacturing process of the product or after opening the product, which is in the food component in the mixed foreign matter. This can be done by analyzing and determining the permeation position (permeation status) and amount (permeation amount) of the organic matter, that is, the degree of permeation by the infrared absorption analysis method.

In the present invention, the "organic substance" in the food component means a substance having a molecular weight of about 50 to 700. Such organic substances have a molecular weight in the range selected from 50 or more, 60 or more, 70 or more, 80 or more, or 90 or more, and 400 or less, 500 or less, 600 or less, or 700 or less, for example, 60. It means a substance having a molecular weight of about 500, preferably 90 to 500, and more preferably about 90 to 400. When the food component is an inorganic compound having a small molecular weight (for example, NaCl (molecular weight 58.5)), a large amount of it immediately permeates deep inside the mixed foreign matter, and the degree of permeation when carrying out the method of the present invention. It may not be possible to obtain a change in the mixing time, and it may be difficult to determine the mixing time. Further, in the case of a food component having a large molecular weight (for example, dextrin (molecular weight 3000-)), the permeation into the mixed foreign matter is slow and does not permeate into the inside, and the degree of permeation changes when the method of the present invention is carried out. It may not be obtained, and it may be difficult to determine the mixing time.

Examples of the "organic matter" that can be used in the present invention include sugars (monosaccharides such as glucose and fructose, disaccharides such as lactose and sucrose, oligosaccharides, etc.), lactic acid, citric acid, acetic acid and the like ( (Not limited to these), one or more can be appropriately selected and used based on the type and properties of the food, the manufacturing conditions and storage conditions of the food, the type and properties of the foreign substance (infrared absorption region), and the like. .. In order to clearly confirm the degree of penetration of the organic substance in the foreign substance by the infrared absorption analysis method, it is preferable that the foreign substance and the organic substance have different infrared absorption regions. When the foreign matter and the infrared absorption region of the organic matter overlap, it may be difficult to determine the degree of penetration of the organic matter in the foreign matter.

The infrared absorption analysis method can be performed by using a generally known conventionally known method, and can be performed by irradiating an object with infrared rays and measuring the absorbed infrared absorption spectrum. In the present invention, it can be carried out by using an apparatus such as a Fourier transform infrared spectrophotometer. In the present invention, the cross section of the foreign substance is irradiated with infrared rays, and the infrared absorption spectrum absorbed by the organic substance permeated into the foreign substance is measured to measure the permeation position (penetration status) and amount (penetration status) of the organic substance in the cross section of the foreign substance. Amount) (degree of penetration) can be determined.

The food component containing the organic substance permeates the foreign matter mixed in the food from the surface layer. As for the degree of permeation, permeation is generally observed from the surface layer portion to the central portion of the foreign substance, and the position (permeation state) and amount (permeation amount) of the organic substance in the cross section of the foreign substance change with the passage of time. Since this degree of penetration correlates with the length of time that the foreign substance has been mixed in the food, the manufacturing conditions of the food, the storage conditions, etc., the time that the foreign substance has been mixed in the food based on this degree of penetration, That is, it is possible to determine when the foreign substance is mixed in the food.

For example, when the food containing foreign substances is a food that has been heat-treated in the manufacturing process, a part of the foreign substances is heat-treated in the same food as the food under the same conditions as the heat treatment in the manufacturing process. Then, the degree of penetration of the organic substance in a part of the cross section of the foreign substance is analyzed by using the above infrared absorption analysis method, and the obtained result is the degree of penetration in a part of the cross section of the foreign substance not subjected to the heat treatment. Can be compared with. Regarding a specific aspect, the foreign matter mixed in the food is first cut using a cutter, a knife, etc., and a part of the obtained foreign matter is the same as the mixed food or the mixed food. In addition to the food, heat treatment (for example, sterilization treatment, fermentation treatment, etc.) is performed under the same conditions as those applied in the manufacturing process of the food. Then, after storing a part of the foreign matter that has been heat-treated under the conditions of refrigeration to room temperature, the cross section of the foreign matter is irradiated with infrared rays based on the irradiation conditions according to the organic matter to be measured, and the degree of penetration of the organic matter in the cross section is measured. do. On the other hand, after storing a part of the foreign matter that has not been heat-treated as a control in the same manner, the degree of penetration of the organic substance in the cross section is similarly measured. Then, the measurement results obtained from both are compared.

If the food containing the foreign matter is a food that has not been heat-treated in the manufacturing process, a part of the foreign matter is mixed again in the same food as the food for a certain period of time, and then one of the foreign matter is mixed. The degree of penetration of organic matter in the cross section of the part can be analyzed using the above infrared absorption analysis method, and the obtained result can be compared with the degree of penetration in a part of the cross section of the foreign matter that has not been remixed. can. Regarding a specific aspect, as in the case of the food heat-treated in the manufacturing process described above, the foreign matter mixed in the food is first cut, and the food or the food containing a part of the obtained foreign matter is mixed. Add it again to the same food as the one that was used, and mix and store it for a certain period of time (re-mixing and storage treatment). Then, the cross section of the foreign substance is irradiated with infrared rays based on the irradiation conditions according to the organic substance to be measured, and the degree of penetration of the organic substance in the cross section is measured. On the other hand, the degree of penetration of organic matter in the cross section is similarly measured for a part of the foreign matter that has not been subjected to the re-mixing / storage treatment as a control. Then, the measurement results obtained from both are compared.

In addition, other comparison methods can be used in addition to the above-mentioned cutting treatment for a part of the foreign matter obtained after processing and storage, respectively, and then comparing the foreign matter. For example, first, various data based on the relationship between foreign substances and foods, food manufacturing conditions, etc. are prepared in advance. For example, a foreign matter control product in which hair is mixed with a specific food and heat-treated is prepared in advance. When a foreign substance (hair) mixed in a food corresponding to a specific food is obtained, the degree of penetration of an organic substance in a cross section is measured by an infrared absorption analysis method without subjecting the foreign substance (hair) to the above-mentioned heat treatment. Similarly, for the foreign matter control product, the degree of penetration of organic matter in the cross section is measured. Then, the measurement results obtained from both can be compared. As a result, the measurement results can be obtained more quickly and accurately and the comparison can be performed without the trouble of the above-mentioned cutting treatment and heat treatment. Even for foods that have not been heat-treated in the manufacturing process, it is possible to measure and compare the degree of permeation of each food by preparing a foreign matter control product that has been remixed and stored in advance by the same method as the above method. can.

In the above method, when measuring the degree of penetration of a food component, it is preferable to set the measurement conditions to be the same, such as the size of the foreign matter to be compared and the measurement portion so as not to have a large influence on the measurement result.

The measurement results can be compared by observing the distribution of the signal intensity (shading) displayed by visualizing the infrared absorption spectrum absorbed by the permeated organic matter in the cross section of the foreign substance, the presence / absence state of the signal portion, and the like. The distribution of the signal intensity (shade), the presence / absence state of the signal portion, etc. are confirmed by using an imaging image represented by the ratio of the signal derived from the organic substance and the signal derived from the foreign substance, as described in detail in the following examples. be able to.

In this case, in the case of foods that have been heat-treated in the manufacturing process, a part of the foreign matter that has been heat-treated is compared with a part of the foreign matter that has not been heat-treated as a control or a foreign matter control product. When both have almost the same signal intensity (shading) distribution, presence / absence state of the signal portion, etc., it can be judged that there is a high possibility that the foreign matter mixed in the food was mixed in the food manufacturing process. .. In addition, in the case of foods that have not been heat-treated in the manufacturing process, a part of the foreign matter that has been re-mixed / preserved and a part of the foreign matter that has not been re-mixed / preserved as a control, or If both have almost the same signal intensity (shading) distribution and presence / absence state of the signal part as compared with the foreign matter control product, it is possible that the foreign matter mixed in the food was mixed in the food manufacturing process. Can be judged to be high.

On the other hand, when the signal strength of a part of the foreign matter not subjected to the heat treatment as a control or the foreign matter control product is weaker or the signal strength is almost nonexistent as compared with the part of the foreign matter subjected to the above heat treatment. Can determine that the foreign matter was mixed in after opening the product. In addition, the signal strength of a part of the foreign matter that has not been subjected to the re-mixing / storage treatment as a control or the signal strength of the foreign matter control product is weaker or that of the signal strength of the part of the foreign matter that has been subjected to the re-mixing / storage treatment as a control. If there is almost no foreign matter, it can be determined that the foreign matter was mixed after the product was opened.

Alternatively, the comparison of the measurement results can be performed based on the presence or absence or difference of the detected value of the organic substance permeated into the foreign matter in the chart displayed by an apparatus such as a Fourier transform infrared spectrophotometer.

In this case, in the case of foods heat-treated in the manufacturing process, a part of the foreign matter subjected to the heat treatment is detected as a part of the foreign matter not subjected to the heat treatment as a control or a foreign matter control product. If it is larger than the value, it can be judged that there is a high possibility that foreign matter has been mixed in after opening the product. On the other hand, if the value difference is small with almost the same detected value, foreign matter is mixed in the food manufacturing process. It can be judged that there is a high possibility that it was done. Further, in the case of foods that have not been heat-treated in the manufacturing process, some of the foreign substances that have been subjected to the above-mentioned re-mixing / preservation treatment are one of the foreign substances that have not been subjected to the re-mixing / preservation treatment as a control. If it is larger than the detected value of the part or foreign matter control product, it can be judged that there is a high possibility that foreign matter has been mixed in after opening the product. It can be judged that there is a high possibility that was mixed in the food manufacturing process.

When foreign matter is mixed in the food manufacturing process, even if a part of the foreign matter is heat-treated in the implementation of the method of the present invention, no significant change in the degree of penetration of the organic matter into the foreign matter is observed.
Hereinafter, the present invention will be described in more detail with reference to Examples.

I. Tests In the following tests, infrared spectroscopic analysis was performed using FT / IR-6600 and IRT-7200 (manufactured by JASCO Corporation).
Regarding the analysis results of infrared spectroscopic analysis, the figure shows a cross section perpendicular to the long axis direction of the hair in each sample. ^{Each figure shows a signal from 1074 cm -1} (1050 ^{to 1115 cm -1} ) derived from the sugar skeleton, or a signal from 1046 cm ^-1 (1000 ^{to 1260 cm -1} ) derived from lactic acid, and 1650 cm derived from hair protein. ^{It is an imaging image represented by the ratio to the signal near -1} , and the closer to red, the higher the signal intensity derived from the target organic substance (sugar (glucose, lactose, etc.) or lactic acid), and more. Indicates the presence of organic matter.

1. 1. Glucose water (1)
Hair was cut with a knife and mixed with 60% glucose water to prepare a sample.
Next, the non-heat-treated sample was stored at 25 ° C. for a predetermined time. On the other hand, the heat-treated sample was subjected to heat treatment at 100 ° C. for 10 minutes and then stored at 25 ° C. for a predetermined time.
After storage, the hair was taken out from each sample, and the degree of glucose penetration in each hair was analyzed by infrared spectroscopic analysis.
The analysis result is shown in FIG.
In the non-heat-treated sample, the permeation of glucose from the surface layer to the central part of the hair was confirmed over time, and the longer the storage period, the greater the degree of permeation into the surface layer and the central part.
Further, in the heat-treated sample, unlike the non-heat-treated sample, permeation into the central part was already confirmed on the 0th day of storage, and a remarkable difference was observed between the two in the sample after storage.

2. Glucose water (2)
Hair was cut with a knife and mixed with 6%, 30% or 60% glucose water, respectively, to prepare a sample.
Next, the non-heat-treated sample was stored at 25 ° C. for a predetermined time. On the other hand, the heat-treated sample was subjected to heat treatment at 80 ° C. for 10 minutes or heat treatment at 121 ° C. for 30 minutes, and then stored at 25 ° C. for a predetermined time.
After storage, the hair was taken out from each sample, and the degree of glucose penetration in each hair was analyzed by infrared spectroscopic analysis.
The analysis result is shown in FIG.
In all the samples, the permeation of glucose from the surface layer to the central part of the hair was confirmed over time depending on the conditions, and the longer the storage period, the greater the degree of permeation into the surface layer and the central part. In addition, the higher the glucose concentration in the sample, the higher the degree of penetration into the surface layer and the central part. Furthermore, in all the samples, the degree of permeation of glucose in the heat-treated sample was larger than that in the non-heat-treated sample, and a remarkable difference was observed between the two.

3. 3. Lactose water Hair was cut with a knife and mixed with 6% or 30% lactose water, respectively, to prepare a sample.
Next, the non-heat-treated sample was stored at 25 ° C. or 4 ° C. for a predetermined time.
On the other hand, the heat-treated sample was subjected to heat treatment at 40 ° C. for 18 hours and then stored at 25 ° C. or 4 ° C. for a predetermined time.
After storage, hair was taken out from each sample, and the degree of lactose penetration in each hair was analyzed by infrared spectroscopic analysis.
The analysis result is shown in FIG.
In all the samples, the permeation of lactose from the surface layer to the central part of the hair was confirmed over time depending on the conditions, and the longer the storage period, the greater the degree of permeation into the surface layer and the central part.
In addition, the higher the lactose concentration in the sample, the greater the degree of penetration into the surface layer and the central part.
In addition, the degree of lactose penetration in the heat-treated sample is larger than that in the non-heat-treated sample in both the case of storage at 4 ° C. and the case of storage at 25 ° C., which is remarkable in both of the samples after storage. A difference was found.

4. Lactic acid water Hair was cut with a knife and mixed with 6% lactate water to prepare a sample.
Next, the non-heat-treated sample was stored at 25 ° C. or 4 ° C. for a predetermined time.
On the other hand, the heat-treated sample was subjected to heat treatment at 40 ° C. for 18 hours and then stored at 25 ° C. or 4 ° C. for a predetermined time.
After storage, the hair was taken out from each sample, and the degree of penetration of lactic acid in each hair was analyzed by infrared spectroscopic analysis.
The analysis result is shown in FIG.
In all the samples, the permeation of lactic acid from the surface layer to the central part of the hair was confirmed over time depending on the conditions, and the longer the storage period, the greater the degree of permeation into the surface layer and the central part.
In addition, a remarkable difference in the degree of penetration between the non-heat-treated sample and the heat-treated sample was observed, and both when stored at 4 ° C. and when stored at 25 ° C., compared with the non-heat-treated sample, The degree of penetration of lactic acid in the heat-treated sample was large, and a difference was observed between the two in the sample after storage.

5. Orange juice Hair was cut with a knife and mixed with orange juice to prepare a sample.
Next, the non-heat-treated sample was stored at 4 ° C. for a predetermined time.
On the other hand, the heat-treated sample was subjected to heat treatment at 65 ° C. for 10 minutes and then stored at 4 ° C. for a predetermined time.
After storage, the hair was taken out from each sample, and the degree of sugar penetration in each hair was analyzed by infrared spectroscopic analysis.
The analysis result is shown in FIG.
In the heat-treated sample, unlike the non-heat-treated sample, permeation into the central part was already confirmed on the 0th day of storage, and no significant difference was observed in the degree of permeation even on the 7th day of storage.
In addition, the degree of permeation of sugar in the heat-treated sample was larger than that in the non-heat-treated sample, and a remarkable difference was observed between the two.

6. Yokan hair was cut with a knife and mixed with yokan to prepare a sample.
Next, the non-heat-treated sample was stored at 4 ° C. for a predetermined time.
On the other hand, the heat-treated sample was subjected to heat treatment at 100 ° C. for 10 minutes and then stored at 4 ° C. for a predetermined time.
After storage, the hair was taken out from each sample, and the degree of sugar penetration in each hair was analyzed by infrared spectroscopic analysis.
The analysis result is shown in FIG.
In all the samples, the permeation of sugar from the surface layer to the central part of the hair was confirmed over time, and the longer the storage period, the greater the degree of permeation into the surface layer and the central part.
In addition, the degree of permeation of sugar in the heat-treated sample was larger than that in the non-heat-treated sample, and a remarkable difference was observed between the two.

7. Blueberry jam Hair was cut with a knife and mixed with blueberry jam to prepare a sample.
Next, the non-heat-treated sample was stored at 4 ° C. for a predetermined time.
On the other hand, the heat-treated sample was subjected to heat treatment at 90 ° C. for 10 minutes and then stored at 4 ° C. for a predetermined time.
After storage, the hair was taken out from each sample, and the degree of sugar penetration in each hair was analyzed by infrared spectroscopic analysis.
The analysis result is shown in FIG.
In all the samples, the permeation of sugar from the surface layer to the central part of the hair was confirmed over time, and the longer the storage period, the greater the degree of permeation into the central part.
In addition, the degree of permeation of sugar in the heat-treated sample was larger than that in the non-heat-treated sample, and a remarkable difference was observed between the two in each storage period.

II. Results From the above results, it was confirmed by infrared spectroscopic analysis that the degree of penetration of organic substances such as glucose, lactose and other sugars and lactic acid into the hair mixed in the sample changes over time over a long span of days. ..

In addition, it was confirmed that the degree of penetration of the organic substance into the hair in the sample subjected to the heat treatment and the degree of penetration of the organic substance into the hair in the non-heat-treated sample were significantly different, and this result was obtained from the sample (food). It is shown whether or not the hair mixed in has a history of being subjected to heat treatment, that is, whether or not the hair mixed in has occurred before the heat treatment in the manufacturing process of the sample (food). ..

Claims (4)

It is a method of determining the mixing time of foreign matter mixed in food, and the degree of penetration of organic substances (excluding fats and oils) having a molecular weight of 50 to 700 in the food component into the mixed foreign matter is measured in the cross section of the mixed foreign matter. by infrared absorption analysis method of irradiating infrared rays, and penetrate into the mixed foreign substance, the infrared absorption spectrum which is absorbed by the organic substances in the food ingredient is measured, based on the infrared absorption spectrum, the cross-section of the mixed foreign substance the method comprising the distribution of signal intensity was analyzed by observing and displayed visualized, based on the analysis result, it determines the mixing time of the foreign material in,
The above method, wherein the mixed foreign matter has a property that the organic substance permeates from the surface layer portion to the central portion thereof. The method according to claim 1, wherein the organic substance is an organic substance selected from the group consisting of monosaccharides, disaccharides, lactic acid, citric acid and acetic acid. When the food is a food that has been heat-treated during the manufacturing process,
A part of the mixed foreign matter is heat-treated in the same food as the food under the same conditions as the heat treatment in the manufacturing process of the food, and the degree of penetration of the organic substance into the heat-treated mixed foreign matter is determined. The method according to claim 1 or 2, wherein the degree of penetration of the organic substance into the mixed foreign matter in the non-heat treatment is analyzed and compared by an infrared absorption analysis method. When the food is a food that has not been heat-treated in the manufacturing process,
A part of the mixed foreign matter is mixed in the food for a certain period of time, and a preservation treatment is performed to allow the organic matter to permeate into the mixed foreign matter. The method according to claim 1 or 2, wherein the degree of penetration of the organic substance into the mixed foreign matter that has not been subjected to the storage treatment is analyzed and compared by an infrared absorption analysis method.

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