How to identify alcohol

Abstract

To highly accurately identify a place of production of Japanese sake.SOLUTION: In a method for identifying rice wine (Japanese sake), a nitric acid component (nitric ion) contained in Japanese sake is used. When further combining this technique with an indicator used in another method, identification of particularly high accuracy can be achieved. To determine a place of production of Japanese sake, a value of δ15 N-NO3- can be used as an indicator. At this time, measurement values other than δ15 N-NO3- can also be used in combination as indicators. In Fig. 9, measurement results for a plurality of types of Japanese sake are shown for each region using a horizontal axis as δ15 N-NO3- and a vertical axis as NO3- concentration. In this case, Akita prefecture, Niigata prefecture and Kyoto prefecture are demarcated as different regions in two dimensions.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to a method for identifying alcoholic beverages (such as Japanese sake). [Background technology]

[0002] A technology for identifying foods using the stable isotope ratios of light elements (carbon, nitrogen, oxygen, hydrogen, etc.) contained in foods is described, for example, in Non-Patent Document 1. Here, plants can be classified into C3 plants (rice, wheat, potatoes, etc.), C4 plants (sugarcane, corn, etc.), and CAM plants (cactus, pineapple, etc.) based on the difference in the photosynthetic method, and the heavy carbon ( 13 Due to differences in the ease of incorporation of C, the carbon isotope ratio ( 13 C / 12 Since the plants that are the source of alcohol in shochu are C3 and C4 plants, the carbon isotope ratio in the alcohol contained in the shochu varies depending on the type of shochu, and this isotope ratio can be used as an indicator to distinguish the type of shochu.

[0003] In addition, Non-Patent Document 2 describes a method for separating the ethanol and glucose components in sake using liquid chromatography, and measuring the carbon isotope ratio δ 13 C and carbon stable isotope ratios δ in glucose components 13 It is described that the type of sake (junmai sake, ginjo sake, ordinary sake) can be determined with high accuracy from these values. 13 C is the "((sample 13 C / 12 C isotope ratio) / (international standard 13 C / 12 It is defined as "C isotope ratio)-1) × 1000 (‰: per mille)".

[0004] Furthermore, with the recent increase in the volume of Japanese sake exports (demand overseas), it has become important to guarantee the origin of Japanese sake, and there is a demand for technology to identify (determine) this origin. The main ingredients of Japanese sake are rice and water (brewing water), and since the water used is from the place of origin, it is possible to obtain information about the origin by analyzing the water used in Japanese sake in particular. Non-Patent Document 3 and Patent Document 1 state that δ 18 It has been reported that the origin of this product can be determined by using δ 18 O is the above-mentioned δ 13 In C 13 C / 12 For oxygen instead of C 18 O / 16 This is a value using the isotope ratio of O. Here, the δ 18 O and δ of water near the production area (brewing area) 18 There is a strong correlation between the δ O and the water in the whole sake. 18 While the O ranges from -12.0 to -5.7‰, sake from Hokkaido, Tohoku, and Hokuriku regions has a higher δ 18 It is described that the range of O is different. Therefore, this δ 18 O can be used as a guideline for determining the place of origin.

[0005] In addition, Non-Patent Document 4 and Patent Document 1 also state that a correlation between the hydrogen stable isotope ratio ΔD in the water content of sake and the region is recognized. 13 In C 13 C / 12 For hydrogen instead of C 2 H / 1 The value of δD in sake is in the range of -70.4 to -35.2‰, and the above δ 18 As with O, it is described that δD can be used as a guideline for determining the origin of sake. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2013-132223 A [Non-patent literature]

[0007] [Non-Patent Document 1] Hanae Izu, Tomokazu Hashiguchi, Yukie Horii, Shigetoshi Sudo, Katsumi Matsumaru, "Stable isotope analysis of commercial authentic shochu," Bunseki Kagaku, Vol. 61, No. 7, p. 643 (2012) [Non-Patent Document 2] Momoka Suto and Hiroto Kawashima, "Compound Specific Carbon Isotope Analysis in Sake by LC / IRMS and Brewes' Alcohol Proportion", Scientific Reports, Vol.9, Article.No.17653 (2019) [Non-Patent Document 3] Shingo Toyama and Tomokazu Hashiguchi, "Identifying the origin of sake using oxygen isotope ratio measurements," Journal of the Brewing Society of Japan, Vol. 110, p. 68 (2015) [Non-Patent Document 4] Nami Sasamoto, Yoshiya Abe, Yuichi Takakuwa, and Izumi Nakai, "Chemical characterization of sake by trace element composition and light element isotope ratios," BUNSEKI KAGAKU, Vol. 66, No. 8, p. 591 (2017) Summary of the Invention [Problem to be solved by the invention]

[0008] When determining the origin of sake, the techniques described in Non-Patent Documents 3 and 4 mainly focus on δ 18 The fact that O and δD depend on geographical conditions such as latitude was used. For this reason, it was difficult to distinguish between other regions in Japan and overseas regions such as China, which have similar geographical conditions. For this reason, the ability to determine regions using these techniques was insufficient.

[0009] For this reason, there was a demand for technology that could identify the origin of sake with greater accuracy.

[0010] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide an invention that solves the above problems. [Means for solving the problem]

[0011] In order to solve the above problems, the present invention has the following configuration. The method for identifying alcoholic beverages of the present invention is a method for identifying a place of origin of alcoholic beverages, comprising: Alcohol An extraction step of extracting a nitric acid component from the nitric acid component, and a nitrogen stable isotope ratio δ of the extracted nitric acid component. 15 A stable isotope ratio measurement step for measuring N; δ of nitric acid content in the feed water 15 The relationship between N and the origin of the water and the δ measured in the stable isotope ratio measurement process 15 From N, and a place of origin estimating step of estimating the place of origin of the sake. In the method for identifying alcoholic beverages of the present invention, a denitrifying bacteria method may be applied in the extraction step. In the method for identifying sake of the present invention, in the origin estimation step, Using the results of comparing the concentration of the nitric acid component in the sake with the corresponding relationship between the concentration of the nitric acid component in the sake brewing water and the origin of the sake brewing water, The place of origin may be estimated. In the method for identifying alcoholic beverages of the present invention, in the stable isotope ratio measurement step, the oxygen stable isotope ratio δ of the nitric acid component is 18 O is measured, and in the origin estimation step, The oxygen isotope ratio of the nitric acid component in the feed water is δ 18 The relationship between the origin of the water and the stable isotope ratio measurement process 15 Using the comparison results of O, The place of origin may be estimated. In the sake identification method of the present invention, the origin estimating step may include estimating a sake brewery within the origin that produced the sake. Effect of the Invention

[0012] Since the present invention is configured as described above, it is possible to identify the origin of sake with high accuracy. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 shows the δ18 and δ15N values ​​of the nitrate component in various samples. [Diagram 2] 1 shows the measurement results of δ18O-NO3 −(a) and δ15N-NO3 −(b) obtained by applying the extraction step and stable isotope ratio measurement step in the alcoholic beverage identifying method of the embodiment to a standard sample. [Diagram 3] These are the results of measuring NO3 - concentrations, δ18O-NO3 -, and δ15N-NO3 - in several types of brewing water. [Figure 4] These are the results of measuring NO3 - concentrations, δ18O-NO3 -, and δ15N-NO3 - in several types of sake. [Diagram 5] The results are based on the NO3 - concentration, δ18O-NO3 -, and δ15N-NO3 - measurement results for brewing water and sake, tabulated by production area. [Figure 6] This is the relationship between the NO3 - concentration in the sample sake and the NO3 - concentration in the brewing water. [Figure 7] This is the relationship between δ18O-NO3- in the sample sake and δ18O-NO3- in the brewing water. [Figure 8] This is the relationship between δ15N-NO3- in the sample sake and δ15N-NO3- in the brewing water. [Figure 9] This is an example showing the classification of sake samples by production area when the δ15N-NO3 - and NO3 - concentrations are plotted on the horizontal and vertical axes, respectively. [Figure 10] The results show δ15N-NO3 - and δ18O-NO3 - for the sample sake on the horizontal and vertical axes, respectively. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The method for identifying sake according to the embodiment of the present invention will be described. In this identification method, the origin of sake is identified. Here, in the techniques described in Non-Patent Documents 3 and 4, O and D used for this identification are contained in the water contained in sake, whereas in the method for identifying sake (sake) according to the embodiment of the present invention, nitric acid components (nitrate ions: NO3 - As will be described later, by combining this method with indices used in other methods, particularly high accuracy of classification is possible.

[0015] No.3 - is contained in the brewing water used in sake production, and plays an important role in the kimoto brewing process, which is one of the methods of sake brewing. Groundwater, well water, and other water produced locally in the region are used. Kimoto brewing is a process for making the yeast starter that is the basis of sake, and is a method that uses natural microorganisms to suppress the growth of unwanted bacteria. While the general method uses artificial lactic acid for brewing, in kimoto brewing, nitrite (NO2) is converted from the nitrates contained in the brewing water by nitrate-reducing bacteria. - ) is produced and the growth of unwanted bacteria is suppressed. Here, the NO3 - It originates from various anthropogenic sources such as chemical fertilizers and human and animal waste.

[0016] For example, C. Kendall, EM Elliott, and SD Wankel, "Tracing Anthropogenic Inputs Of Nitrogen To Ecosystems", Capter 12, in "Stable Isotopes In Ecology And Environmental Science", 2nd Edition, Blackwell Publishing, p.375, Fig. 12.1 shows the concentration of nitrate ions (NO3 - ) Oxygen stable isotope ratio δ 18 O(δ 18 O-NO3 - ), nitrogen stable isotope ratio δ 15 N(δ 15N-NO3 - ) varies depending on the sample. Here, δ 18 O (or δ 15 N) is the number of samples 18 O / 16 O isotope ratio, or 15 N / 14 N isotope ratio) / (international standard 18 O / 16 O isotope ratio, or 15 N / 14 It is defined as "N isotope ratio)-1) x 1000 (‰: per mille)".

[0017] FIG. 1 shows the contents described in FIG. 12.1, where δ 18 O-NO3 - and δ 15 N-NO3 - The values ​​of δ are shown. Note that plots have been added to the original diagram, which will be explained later. As shown here, the soil δ 15 N-NO3 - The δ of nitrate ions in sake varies over a wide range of -10‰ to +25‰ depending on the type of fertilizer (manure (organic fertilizer), fertilizer (chemical fertilizer)), septic waste, and the presence or absence of precipitation (rainfall). It is also greatly affected by factors other than geographical and meteorological conditions, such as human domestic wastewater. 15 N-NO3 - It is thought that there is also a dependency due to the origin of the brewing water for . In addition, since the brewing water is determined for each sake brewery, this dependency can also be considered as a dependency due to the sake brewery. 18 While O and δD reflect the geographical conditions (latitude, etc.) of this region, as mentioned above, δ reflects the human life activities of this region, and is therefore effective as information for identifying this region. 15 N-NO3 - By combining this with other evaluation values ​​that correspond to dependencies reflecting geographical conditions, it is possible to accurately determine the place of origin (brewery), in particular.

[0018] For this reason, this identification method includes (1) an extraction process for extracting nitric acid components from a sample (sake), (2) measuring the stable isotope ratio (especially the nitrogen stable isotope ratio) in the extracted nitric acid components, and then calculating δ 15 (3) a stable isotope ratio measurement process to calculate N etc., and (4) the measured δ 15 and a step of estimating the origin of the sample based on N etc. Each step will be described in detail below.

[0019] The extraction step is performed to extract nitrate components from the sample, for example, by applying a denitrification bacteria method to the sample. The denitrification bacteria method is described in DM Sigman, KL Casciotti, M. Andreani, C. Barford, M. Galanter, and JK Bohlke, "A Bacterial Method For The Nitrogen Isotopic Analysis Of Nitrate In Seawater And Freshwater," Analytical Chemistry, Vol. 73 (17), p. 4145 (2001), and is a method of obtaining nitrate components of a sample as NO gas using denitrification bacteria.

[0020] According to the denitrification bacteria method, N(δ 15 N) and O(δ 18 The denitrification method is particularly preferred because it can perform highly sensitive analysis of NO3O in groundwater, rivers, and seawater and requires only a small amount of original sample. - δ in the component 15 N, δ 18 It is used when analyzing sake. However, when performing the above-mentioned analysis, it is preferable to remove impurities such as ethanol and sugars contained in the sample (sake). For this reason, it is preferable to remove these in advance by solid phase extraction.

[0021] The procedures and results of the extraction process and stable isotope ratio measurement process applied to standard reagents and samples (various types of sake) are described below. These processes were also applied to the brewing water used in the production of sake.

[0022] The standard reagent is a pseudo-sake with a known composition and similar composition to the sake created to confirm the validity of the results for the sample. Here, the standard reagent was created by mixing L(+)-tartaric acid (>99.5%), malic acid (>99.0%), lactic acid (85.0-92.0%), succinic acid (>99.5%), L-alanine (>99.0%), L-glutamic acid (> 99.0%), ethanol (>99.5%), potassium nitrate (all manufactured by Fujifilm Wako Pure Chemical Industries), and D(+)-glucose (>98.0%) (manufactured by Kanto Chemical). Here, the nitric acid component is contained in potassium nitrate.

[0023] A total of 87 types of sake were sampled from 14 breweries (8 in Akita Prefecture, 2 each in Niigata Prefecture and Kyoto Prefecture, 1 each in Ishikawa Prefecture and Fukui Prefecture), with 2 to 11 types per brewery. Here, sake was classified into three types: "junmai sake," made only with water, rice, and koji; "ginjo sake," which can also contain brewing alcohol; and "normal sake," which can also contain sugar and organic acids. In addition to these sakes, the brewing water used during brewing was obtained from each of the 14 breweries and used for analysis.

[0024] In the extraction process, the ethanol component was removed by the solid-phase extraction method using an anion exchange resin cartridge (product name AG1-X8: manufactured by Bio-Rad) that was filled into an empty polyethylene cartridge. Here, extraction was performed using hydrochloric acid (HCl: 35-37%: manufactured by Fujifilm Wako Pure Chemical Industries).

[0025] To optimize this process, the above-mentioned standard reagent was used as described in Fumikazu Akamatsu, Tomokazu Hashiguchi, Yuri Hisatsune, Takaaki Oe, Takafumi Kawao, Tsutomu Fujii, "Method For The Isolation Of Citric Acid And Malic Acid In Japanese Apricot Liqueur For Carbon Stable Isotope Analysis", Food Chemistry, Vol. 217, p. 112 (2017). Specifically, the above-mentioned ethanol / water (volume ratio 16:84), D(+)-glucose: 20,000 ppm, malic acid: 300 ppm, lactic acid: 800 ppm, succinic acid: 300 ppm, L-alanine: 250 ppm, L-glutamic acid: 150 ppm, and potassium nitrate was further mixed at 1 to 10 ppm to prepare a mixture. The δ in the potassium nitrate used here was 18 O-NO3 - is 23.7‰, δ 15 N-NO3 - was -1.9‰.

[0026] Using this standard reagent, NO3 - The amount of the solution passed was set to 5 to 50 mL so that the absolute amount of ion exchange resin was 0.4, 0.8, 2.0, 4.0, and 8 μmol. Here, 0.25 mL of a mixture of the ion exchange resin and ultrapure water in a weight ratio of 1:1 was filled into the empty polyethylene cartridge 1 mL, and 50 mL of ultrapure water was passed through as conditioning to activate the ion exchange resin.

[0027] In particular, for the actual sample (sake), in order to remove the above-mentioned impurities, the sample was passed through a 0.45 μm membrane filter, and 15 to 25 mL of the sample was passed through at a flow rate of 1 mL / min or less. Finally, the sample was diluted with 1 M of the above-mentioned hydrochloric acid and diluted with NO3 - was extracted.

[0028] Then, using the well-known denitrification method, the extracted components are treated with NO3 -Denitrifying bacteria were added so that the amount of NO reduced to NO was 30-50 nmol N. This allowed the extraction of the NO component, which was the direct target for measuring the nitrogen isotope ratio and oxygen isotope ratio (extraction process).

[0029] Next, the nitrogen isotope ratio δ was measured for this component using a combination of Gas Bench II (Universal Online Gas Preparation / Introduction System: Thermo Fisher Scientific) and a stable isotope ratio mass spectrometer (IRMS: DeltaplusXP: Thermo Fisher Scientific). 15 N(δ 15 N-NO3 - ), oxygen isotope ratio δ 18 O(δ 18 O-NO3 - ) was measured (stable isotope ratio measurement step). The software used for analysis in IRMS was ISODAT3.0 (manufactured by Thermo Fisher Scientific). δ 15 N-NO3 - , δ 18 O-NO3 - is the international isotope standard for potassium nitrate (USGS32:δ 15 N=180‰, USGS34:δ 15 N=-1.8‰), and the international isotope standard for sodium nitrate (USGS35:δ 15 N=2.7‰) was used and calculated using a two-point calibration curve method.

[0030] In addition, NO3 in the sample (including the preparation water) - The concentration was also measured using an ion chromatograph. Here, the sample was passed through a membrane filter to remove impurities as described above, and an ion chromatograph (product name IC2010: manufactured by Tosoh Corporation) was used to measure NO3 - The concentration of NO3 was measured. The columns used for anion analysis were TS Gelguard Column Super IC-AHS and TSK Gel Super IC Anion HS. A calibration curve was created by diluting and analyzing a mixed anion standard solution (manufactured by Wako Pure Chemical Industries, Ltd.). The coefficient of determination was >0.999, and NO3- The detection limit was 10 ppb.

[0031] First, to verify the validity of the measurement, the δ 18 O-NO3 - , δ 15 N-NO3 - The amount of nitric acid adsorbed was measured in the range of 0.4 to 8.1 μmol. 18 O-NO3 - , δ 15 N-NO3 - The results of the measurements are shown in Fig. 2(a) and (b), respectively. 18 O-NO3 - The values ​​of (a) were 23.4±0.3‰ (0.4 μmol), 24.1±0.2‰ (0.8 μmol), 24.3±0.1‰ (2.0 μmol), 24.3±0.04‰ (4.0 μmol), and 24.3±0.1‰ (8.1 μmol), with accuracy ≦0.6‰ and precision ≦0.3‰. 15 N-NO3 - The values ​​of (b) were -1.5±0.1‰ (0.4μmol), -1.5±0.1‰ (0.8μmol), -1.5±0.1‰ (2.0μmol), -1.7±0.1‰ (4.0μmol), and -1.6±0.1‰ (8.1μmol), with an accuracy of ≦0.4‰ and precision of ≦0.1‰. 18 O-NO3 - , δ 15 N-NO3 - is measured with high precision.

[0032] Next, using ion chromatography as described above, NO3 in 14 types of brewing water, each corresponding to a sake brewery, was measured. - The concentration was measured as above, and NO3 - The components were extracted and δ was measured using IRMS as described above. 18 O-NO3 - , δ 15 N-NO3 -The results are shown in the table in Figure 3. Here, of the 14 types of sake breweries, Breweries 1-1 to 1-8 belong to Akita Prefecture, Breweries 2-1 and 2-2 belong to Niigata Prefecture, Brewery 3-1 belongs to Ishikawa Prefecture, Brewery 4-1 belongs to Fukui Prefecture, and Breweries 5-1 and 5-2 belong to Kyoto Prefecture.

[0033] From these results, NO3 in the brewing water - The concentrations ranged from 1.4 to 25.6 ppm (average: 8.2 ± 6.6 ppm), and it can be seen that there are significant differences between breweries. However, because these concentrations are significantly lower than the environmental standards, there are no safety issues.

[0034] On the other hand, in FIG. 18 O-NO3 - is in the range of -0.04 to 5.7‰ (average: 2.4±1.5‰), and δ 15 N-NO3 - The range of δ is 2.0 to 11.2‰ (average: 6.7±2.7‰). 15 N-NO3 - δ is better 18 O-NO3 - Greater than.

[0035] In Figure 1, the results of Figure 3 (δ for each of the 14 sake breweries) are shown in the figure by Kendall et al. 18 O-NO3 - , δ 15 N-NO3 - ) is added as a plot. According to Kendall et al., δ 18 O-NO3 - is about -10 to +10‰, while δ 18 O-NO3 - The results in Fig. 3 (δ 18 O-NO3 - (range of -0.04 to 5.7‰) is the NO3 - The components indicate that they are more likely to originate from human activities, such as chemical fertilizers and human and livestock waste through nitrification, rather than from the atmosphere.

[0036] In contrast, δ in Fig. 3 15 N-NO3 - The results of δ (range 2.0-11.2‰) are considered to be derived from nitrogen in uncontaminated natural soil, as shown in Figure 1. The values ​​in breweries 1-1, 2-1, 3-1, 5-1, and 5-2 are higher than in this range, which is considered to indicate that these breweries are more affected by nitrate ions derived from humans and livestock than the other breweries. 15 N-NO3 - The value can also be used as an indicator to judge not only regions but also sake breweries.

[0037] Figure 4 shows the NO3 concentration in sake after production, similar to Figure 3 (brewing water). - concentration, δ 18 O-NO3 - , δ 15 N-NO3 - The results are classified by sake brewery. The number of types of sake samples is also shown for each brewery. 18 O-NO3 - The range of δ is 2.3 to 9.1‰, and the δ 18 O-NO3 - The standard deviation of δ was 1.4‰. 18 O-NO3 - While the difference is large outside the home, the difference is small within the brewery.

[0038] Figure 5 shows the results of the measurements in Figure 3 (brewing water) and Figure 4 (sake) tabulated by production area (prefecture). The number of sake breweries in each prefecture (Figures 3 and 4) is also shown here. From these results, δ 18 O-NO3 - is 4.3±1.5‰ in Akita Prefecture, 6.7±3.5‰ in Niigata Prefecture, 3.9±0.3‰ in Ishikawa Prefecture, 2.3±0.8‰ in Fukui Prefecture, and 5.6±1.0‰ in Kyoto Prefecture. 15 N-NO3 - is 6.1±1.6‰ in Akita Prefecture, 4.3±4.1‰ in Niigata Prefecture, 7.5±0.4‰ in Ishikawa Prefecture, 3.2±0.1‰ in Fukui Prefecture, and 11.6±1.0‰ in Kyoto Prefecture. From these results, the difference between the production areas is δ 15N-NO3 - δ is better 18 O-NO3 - This is because δ 15 N-NO3 - This is thought to be because the above-mentioned regional differences in human activity conditions are more clearly reflected in the δ . In addition, even within the same brewery, the δ will vary depending on the type of sake, depending on the type of yeast (kimoto yeast, fast brewing yeast, etc.) and the rice polishing ratio. 18 O-NO3 - , δ 15 N-NO3 - No significant difference was observed. 15 N-NO3 - This can be used as an indicator to determine the origin of sake.

[0039] Figure 6 shows the NO3 of sake based on the results of Figures 3 and 4. - Concentration and NO3 in the water - The results show the correlation between the NO3 concentration in sake. The results show that there is a correlation between the two, and the coefficient of determination R when the two are linearly approximated is 0.76. - The majority of the concentration comes from the brewing water. However, the NO3 - The concentration is NO3 in the preparation water. - The concentration is 0.5 to 16.2 ppm (3.8 ppm in linear approximation) lower than the concentration. The reason for this is that the reduction reaction that occurs during the manufacturing process causes NO3 - During the manufacturing process, some of the NO3 - This is thought to be due to the decomposition of a portion of

[0040] Similarly, FIG. 7 shows the δ 18 O-NO3 - and δ of the brewing water 18 O-NO3 - The results show a correlation between these. - However, in all samples, sake had a higher δ concentration than brewing water. 18 O-NO3 - has increased, with the average difference being +2.2‰.

[0041] On the other hand, Figure 8 shows the δ 15 N-NO3 - and δ of the brewing water 15 N-NO3 - The results show a correlation between these. - concentration), Fig. 7 (δ 18 O-NO3 - ) is stronger (R = 0.90). 15 N-NO3 - is the delta of the brewing water. 15 N-NO3 - The brewing water is used for sake breweries, so it reflects the δ 15 N-NO3 - This can be used as an indicator to judge the brewery that produced this sake.

[0042] For this reason, in order to identify the origin or brewery of sake, it is necessary to consider the amount (parameter) of sake that is caused by its brewing water, particularly its δ 15 N-NO3 - However, it is more preferable to use other parameters of sake in combination for this judgment. Such other parameters include NO3 - Concentration and δ 18 O-NO3 - Figure 9 shows the measurement results (Figure 4) for several types of sake, with the horizontal axis being δ 15 N-NO3 - , the vertical axis is NO3 - The concentration is shown for each region in Figure 5. In this case, Akita Prefecture, Niigata Prefecture, and Kyoto Prefecture are divided into different regions on a two-dimensional plane. That is, the δ 15 N-NO3 - , NO3 - The concentration can be used to determine the place of origin.

[0043] Also, Figure 10 shows the No. 3 in Figure 9. - Converting it to concentration, δ 18 O-NO3 -The plot types are the same as in Figure 9. From these results, the division of Akita Prefecture and Kyoto Prefecture is at least clear. 15 N-NO3 - , NO3 - concentration, δ 18 O-NO3 - These three can be used simultaneously as indices. In this case, δ 15 N-NO3 - , NO3 - concentration, δ 18 O-NO3 - By setting regions in the 3D data with each axis as a corresponding region to the place of origin and determining which region the data for the sample sake belongs to, it is possible to determine the place of origin of the sake. Alternatively, it is also possible to create a profile in the 3D data for each sake brewery and identify the brewery that produced the sake.

[0044] Combining multiple parameters in this way to make judgments is particularly effective against fraudulent claims about the origin of sake. For example, it is possible to newly add NO3 to sake from different origins (including outside Japan). - The components are added, and δ 15 N-NO3 - and δ 18 O-NO3 - It is possible to falsify the place of origin by adjusting the value of δ to correspond to a certain place of origin in Japan (for example, Akita Prefecture). 15 N-NO3 - , δ 18 O-NO3 - If these two indicators were used, this falsification would not be discovered.

[0045] However, in this case, new NO3 - Since ingredients are added, the NO3 - In many cases, the concentration increases significantly, and NO3 - There is a high possibility that the concentration will be outside the range of this production area (Akita Prefecture) or the range of general sake. -It is useful to include the concentration of NO3 - Add ingredients and add δ 15 N-NO3 - , δ 18 O-NO3 - To simultaneously set the two in the desired range, for example, δ 15 N-NO3 - It is more difficult to adjust only NO3 to the desired range. - The concentration is δ 15 N-NO3 - It is effective to use it in combination with the above as an indicator.

[0046] In addition, as described in, for example, Takashi Nakamura, Ken-ichi Osaka, Yuki Hiraga, and Futaba Kazama, "Nitrogen And Oxygen Isotope Composition Of Nitrate In Stream Water Of Fuji River Basin", Vol. 41(3), p. 79 (2011), the δ 18 O-NO3 - , δ 15 N-NO3 - are in the range of -4.2 to +48‰ and -6 to +46‰, respectively. In contrast, for example, Xin Zhang, Yan Zhang, Peng Shi, Zhilei Bia, Zexuan Shana, and Lijiang Ren, "The Deep Challenge Of Nitrate Pollution In River Water Of China," Science Of Total Environment, Vol. 770, p144674 (2021), 18 O-NO3 - , δ 15 N-NO3 - are in the range of -12.7 to +83.5‰ and -23.5 to +26.9‰, respectively. 18 O-NO3 - , δ 15 N-NO3- In many cases, it is possible to distinguish between sake made in Japan and sake made in China using δ. In other words, in the above-mentioned origin estimation process, it is also possible to distinguish between sake made in Japan and sake made in China. For this reason, in this respect, 18 O-NO3 - δ 15 N-NO3 - It is effective to use it in combination with the above as an indicator.

[0047] That is, δ 15 N-NO3 - By using one or more parameters including at least the above as indexes, it is possible to determine the place of origin (brewery) of sake, and by using multiple parameters, the determination can be made more accurately. In this case, these parameters of many sakes or brewing waters whose origins are known in advance are measured by applying the above-mentioned extraction process, stable isotope ratio measurement process, etc., and compiled into a database. As shown in Figure 9, regions corresponding to the place of origin or brewery are set, and by determining which region the parameters measured in a sample (sake of unknown place of origin) belong to, the place of origin of this sample can be determined (place of origin estimation process). This determination can be easily made by a computer that stores the above-mentioned database.

[0048] In this case, for example, the place of origin and brewery of a certain sake may be specified, but the brand (type) may be unknown, or the corresponding data may not be in the database. In such a case, if the above data on the corresponding brewing water is stored in the database as described above, for example, the δ 15 N-NO3 - The range of δ of this sake can be estimated from this range. 15 N-NO3 - If there is a large difference between the two, it is determined that the sake is likely to be counterfeit. In this case, a highly accurate regression equation such as that shown in the figure may be used. In other words, it is possible to determine whether sake is counterfeit even if the specific place of origin or brewery is not specified.

[0049] In the above example, the subject of identification was sake, but it is possible to identify the place of origin of any alcoholic beverage that uses local water (natural water) as an ingredient. The same can be said for beverages other than alcohol, and for agricultural products such as vegetables.

[0050] In addition, in the above method, the denitrifying bacteria method is used to extract the nitrate component from the sample, but other methods may be used as long as they can similarly extract the nitrate component.

Claims

1. A method for identifying an alcoholic beverage by identifying the place of origin of the alcoholic beverage, comprising the steps of: An extraction step of extracting nitric acid components from the liquor; The nitrogen stable isotope ratio of the extracted nitric acid component is δ １５ A stable isotope ratio measurement step for measuring N; a step of estimating the origin of the sake from the relationship between the δ 15 N of the nitrate component in the brewing water and the origin of the brewing water and the δ 15 N measured in the stable isotope ratio measurement step; A method for identifying alcoholic beverages, comprising:

2. 2. The method for identifying alcoholic beverages according to claim 1, wherein a denitrifying bacteria method is applied in the extraction step.

3. The method for identifying sake as described in claim 1 or 2, characterized in that in the origin estimation step, the origin is estimated using a comparison result between the concentration of nitric acid components in the brewing water and the origin of the brewing water, and the concentration of the nitric acid components in the sake.

4. In the stable isotope ratio measurement step, the oxygen stable isotope ratio δ of the nitric acid component is １８ Measure O, The method for identifying sake according to any one of claims 1 to 3, characterized in that in the origin estimation step, the origin is estimated by also using a comparison result between the correspondence between the oxygen isotope ratio δ 18 O of the nitric acid component in the brewing water and the origin of the brewing water and the δ 15 O measured in the stable isotope ratio measurement step.

5. In the origin estimation step, The method for identifying sake according to any one of claims 1 to 4, further comprising estimating a sake brewery in the production area that produced the sake.

Images