JP2003194778A - Method for specifying raw material in food - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a carbon isotope ratio in food for comparing with an origin isotope ratio to estimate or specify the manufacturing raw material or the like of the food since a carbon stable isotope ratio δ<SP>13</SP>C greatly differs in rice, wheat (C3 plant), maize, and sugar cane (C4 plant) in a plant. <P>SOLUTION: Carbon in a sample food is recovered as a carbon dioxide gas by a sealed tube combustion method, the carbon isotope ratio is obtained by a stable isotope specific mass analyzer and is compared with the carbon isotope ratio of an origin raw material, and the deviation from<SP>13</SP>C/<SP>12</SP>C of an international standard sample is expressed by permillage in the carbon isotope ratio in the sample food. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to the field of identifying raw materials in foods by utilizing the unique carbon isotope ratio of each raw material.

[0002]

2. Description of the Related Art Due to the recent progress in organic synthesis technology, some chemically synthesized products, which are not inferior in quality to natural products, are distributed in foods. This is because, while natural products are expensive, chemically synthesized products are inexpensive and have high productivity, and can flexibly meet the demands of general consumers. However, at present, there is no means other than judging the displayed label.

[0003]

Carbon is a radioactive isotope.
Is the body¹⁴C and stable isotope¹²C,^ThirteenC is
Exists. Atmospheric¹⁴C is after the Industrial Revolution¹⁴All C
Decrease due to large consumption of fossil fuels that do not contain much, 1960
Peaked under the influence of world-wide nuclear tests in the 1980s
After that, it is gradually decreasing thereafter. This trend is food
Is also reflected in. Also, fossil fuels are used as raw materials for food.
Because the chemically synthesized product is mixed, ¹⁴C concentration
Will be diluted relative to the current level. on the other hand,
Stable carbon isotope ratio in plants δ^ThirteenC is a C3 plant
(Meat, wheat) and C4 plants (corn, sugar cane)
It is greatly different, and is −22 ‰ to −32 ‰, −10 ‰, respectively.
It is known to exhibit -16%. Therefore, δ
^ThirteenIdentify C3 or C4 plants in food from C value
It is possible to

The present invention aims to identify or identify raw materials of foods for carbon isotope ratios.

[0005]

In order to achieve the above object, the present invention firstly collects carbon in a sample food as carbon dioxide gas by a sealed tube combustion method, and recovers the carbon dioxide by a stable isotope ratio mass spectrometer. A method for identifying a raw material in food, which is characterized by obtaining an isotope ratio and comparing it with the carbon isotope ratio of the source material. Second, the carbon isotope ratio in the sample food is determined by the ¹³ C of the international standard sample.
The method for identifying a raw material in food according to the first aspect of the present invention, wherein the deviation from / ¹² C is displayed in thousandths.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION As a pretreatment method for various organic material samples, a sealed tube combustion method using a quartz tube or a glass tube is selected,
The carbon in the sample is finally recovered as carbon dioxide. For coal, plants, food, suspended organic matter, and cellulose, quartz tubes are used to raise the combustion temperature. On the other hand, a glass tube is used for a sample such as petroleum that is relatively easy to burn or a sample in which impurities are apparently small.

Regarding the sealed tube combustion method, samples are coal, plants,
The following is an experimental example of the case of food and suspended organic matter.

(Experimental Example 1) Preparatory work Quartz tube with one side closed (9 mmφ x 280 mm, 6 mmφ)
× 80 mm), 1 g of copper oxide, silver foil (0.05 × 40 × 5)
mm) (Cl is removed as AgCl). 1. Analytical procedure The vacuum line is started up in FIG. 1. Vacuum cock closed: V-1, V-2, V-3, V-5, V-
6, V-7, V-8, V-9, V-10, V-11, V
-12, V-13, V-14, V-15 Vacuum cock open: V-4, V-16 Vacuum pump cock: rough evacuation The oil rotary pump is evacuated to ON for 10 minutes in the above state.

With the vacuum cock as it is, the cock of the vacuum pump is changed from roughing to auxiliary drawing and exhaust is performed for 10 minutes.

With the vacuum cock as it is, the cock of the vacuum pump is changed from the auxiliary pull to the rough pull, the cooling fan and the diffusion pump are turned on in this order, and the diffusion pump is evacuated for 20 minutes while being cooled with liquid nitrogen (the diffusion pump is always in the liquid state). Use while cooling with nitrogen).

The quartz tube (9 mmφ × 280) was used for sample preparation.
mm) and put 0.5 g of reduced copper into the quartz tube (6 mmφ)
Copper oxide 1 g, silver foil (0.05 × 40 × 5)
mm) and the sample in that order, and then put into a quartz tube (9 mmφ × 280 mm) containing the reduced copper.

For sample encapsulation, the quartz tube containing the sample is attached to a caulking joint K-4, a vacuum cock V-3 is opened and the Pirani gauge P-2 is evacuated to 2 Pa or less.

When the Pirani gauge P-2 becomes stable at 2 Pa or less, the cock of the vacuum pump is changed from roughing to auxiliary drawing, and gas is evacuated until the Pirani gauge P-2 becomes 0.5 Pa or less.

When the Pirani gauge P-2 is 0.5 Pa or less, the portion 180 mm from the bottom of the quartz tube is burned off with a gas burner and the sample is enclosed. The enclosed quartz tube is heated in an electric furnace at 850 ° C. for 2 hours to obtain a sample CO ₂ . CO ₂ can be similarly obtained from petroleum and cellulose.

(CO ₂ Recovery and Purification) Next, the above lime, plants, foods, suspended organic matter, petroleum and cellulose are CO
₂ Recovery and purification will be described.

To start up the vacuum line, the vacuum cock is closed (V-1, V-2, V-3, V-10, V-13, V-.
16), open the vacuum cock (V-4, V-5, V-6, V-
7, V-8, V-9, V-11, V-12, V-14,
(V-15, V-16), turn on the oil rotary pump in the state of roughing the cock of the vacuum pump, and evacuate for 10 minutes. Then, while the vacuum cock is kept as it is, the cock of the vacuum pump is changed from roughing to auxiliary drawing and exhaust is performed for 10 minutes. Also, with the vacuum cock as it is, turn the cock of the vacuum pump from the auxiliary pull to the rough pull, turn on the cooling fan and the diffusion pump in this order, and evacuate for 20 minutes while cooling with liquid nitrogen (while the diffusion pump is always cooling with liquid nitrogen, use).

To prepare for CO ₂ recovery, a breaker is used in the Cajon joint K-4, a heat-treated sample-encapsulated quartz tube is used in the Cajon joint K-5, and the Cajun joint K.
Glass tubes (6 × 260 mm) were attached to -6 and K-7, vacuum cocks V-3, V-10, and V-13 were opened, and evacuation was performed until the Pirani gauge P-2 became 2 Pa or less.
Then, the cock of the vacuum pump is changed from roughing to auxiliary drawing, and the air is exhausted until the Pirani gauge P-2 becomes 0.5 Pa or less.

When making a CO ₂ recovery line, the vacuum cock is closed (V-1, V-2, V-4, V-6, V-7, V).
-8, V-10, V-11, V-12, V-15), vacuum cock open (V-3, V-5, V-9, V-13, V-
14, V-16) and a trap T-
1 is dry ice-alcohol, and the glass tube of trap T-2 and Cajon joint K-7 is cooled with liquid nitrogen.

When CO ₂ is to be recovered, the sample-enclosed quartz tube attached to the Cajon joint K-5 is broken by a breaker. When the scale of the Pirani gauge P-2 is stable, open V-6. Then, when the scale of the Pirani gauge P-2 becomes stable, the vacuum cock V-7 is opened and exhausted. After the evacuation, when the scale of the Pirani gauge P-2 becomes stable, the vacuum cocks V-6 and V-7 are closed, and the vacuum cock V-
8. Open V-11. Remove liquid nitrogen of T-2 T
The CO ₂ recovered in -2 is vaporized and stored in a glass tube.

CO_TwoFor quantification of
When P-1 becomes stable, close the vacuum cock V-11 and
The liquid nitrogen attached to the tube was removed and recovered.
CO _TwoCO vaporized and vaporized CO_TwoIs quantified with a pressure gauge
It

For sealing the sample, the vacuum cock was left as it was, and the bottom of the glass tube was cooled with liquid nitrogen to 120
Burn out and enclose at mm with a gas burner. The reagents are shown in the list below.

[0022]

[Table 1]

Carbon isotope ratio measurement (1) Measuring instrument Stable isotope ratio mass spectrometer (SI-MS) -Delta of Finngan MAT-McKinney type mass spectrometer with triple collector (2) Standard sample International standard sample: USA Belemnite from Peedy Formation, South Carolina (3) Method for displaying stable carbon isotope ratios ¹² C and ¹³ C exist as stable carbon isotopes in environmental samples. The composition of carbon isotope is ¹³ C /
The deviation from ¹² C is displayed in thousandths, and is represented by the following δ ¹³ C value. δ ¹³ C = [( ¹³ C / ¹² C) sample / ( ¹³ C /
¹² C) CDT-1] ^{× 1000 (‰) (13 C} / 12 C) sample: Sample of ^{13 C / 12 C (13 C} / 12 C) CDT: International standard sample ¹³ C ^{/ 12}
C

Source Estimation Method Atmospheric carbon dioxide, environmental samples such as plants, or fossil fuels such as petroleum and coal show different carbon isotope ratios for each sample. Δ ¹³ C value of carbon in the target sample whose origin is to be estimated,
By comparing the δ ¹³ C values of the sources, it is possible to find the source of carbon in the target sample.

The carbon isotope is a stable isotope.
^In addition to ¹² C and ¹³ C, there is a radioactive isotope, ¹⁴ C. ¹⁴ C is a naturally occurring nuclide (β-ray emitting nuclide, half-life: 5730 years). However, fossil fuels such as oil and coal, to be formed through the comparison very long periods on the half-life of ^{14 C,} contains no ^{14 C.}
Therefore, if fossil fuel-derived carbon is mixed in the environmental sample, its concentration will decrease. It is possible to estimate the inclusion of fossil fuels from the degree of the decrease.

The procedure for estimating the carbon source by measuring the δ ¹³ C value and ¹⁴ C concentration of environmental samples is shown below.

Procedure for carbon source estimation (1) Selection of target sample: Select the target sample to be estimated.
In addition, since the δ ¹³ C value differs for different chemical forms,
It is necessary to examine in advance which chemical form is targeted. (2) Selection of sampling method: Select a sampling method suitable for the target sample. (3) Sampling: Sampling suitable for the target sample is performed. (4) Pretreatment and δ ¹³ C value and ¹⁴ C concentration measurement: Pretreatment and measurement method for δ ¹³ C value measurement are in accordance with “(a) Sampling and pretreatment”. The pretreatment / measurement method for measuring ¹⁴ C concentration is based on the benzene synthesis-liquid scintillation counting method. (5) δ ^{13 C} value of the information collection carbon sources: collecting information of [delta] ^{13 C} value of the source sample. ¹⁴ C of fossil fuel
The concentration is 0 mBq / (1 g-Carbon). (6) Estimation of carbon source: The origin of carbon is estimated by comparing the δ ¹³ C value of the target sample with the δ ¹³ C value of the source sample. In addition, the degree of contamination of fossil fuels is estimated by comparing the ¹⁴ C concentration of the target sample with the ¹⁴ C concentration of the general environmental level.

The δ ¹³ C values of carbon samples obtained according to the present invention are shown below. The details of the data are shown in Tables 3 and 4.

[0029]

[Table 2] Carbon stable isotope ratios and radiocarbon concentrations of carbon samples

[0030]

[Table 3] Carbon stable isotope ratio of coal

[0031]

[Table 4] Carbon stable isotope ratio of petroleum

[0032]

[Example] (Example 1) 1. Purpose Measurement of atmospheric carbon dioxide radiocarbon concentration around coal-fired power plants 2. Sample atmospheric carbon dioxide 3. Sampling point (1) A coal-fired power plant (2) B geothermal power plant (3) C coal-fired power plant (4) D city 4. Sampling periods (1), (2), (4): August 1998-February 2000 (3): August 1999-February 2000 5. Evaluation-Radioactive carbon concentration of carbon dioxide in the atmosphere and stable carbon isotope ratio: Table 5-Radioactive carbon concentration of carbon dioxide in the atmosphere collected around the A power plant: Fig. 2 ・ Atmospheric carbon dioxide collected around the B power plant Radiocarbon concentration of: Fig. 3 ・ Radiocarbon concentration of atmospheric carbon dioxide collected near the C power plant: Fig. 4 ・ Radiocarbon concentration of atmospheric carbon dioxide collected in D city:
Figure 5

[0033]

[Table 5]

(Example 2) 1. Radioactive carbon concentration in target foods and stable carbon isotope ratio-Use for feature inspection-2. Introduction With the progress of organic synthesis technology in recent years, some foods have chemical synthetic products that are not inferior in quality to natural products. This is because, while natural products are expensive, chemically-synthesized products are inexpensive and have high productivity, and can flexibly meet the needs of general consumers. However, at present, the general consumer can determine whether the product is a natural product or a chemically-synthesized product and confirm the identity thereof by no means other than the label displayed on the food.

Carbon is a radioactive isotope, ¹⁴ C (β
-Ray emitting nuclides, half-life 5730) and stable isotopes ¹² C and ¹³ C. The concentration of ¹⁴ C in the atmosphere has decreased since the industrial revolution due to the large consumption of fossil fuels that do not contain ¹⁴ C at all, and peaked under the influence of a nuclear test conducted on a global scale in the 1960s. It has been revealed by an annual ring analysis. This trend should be reflected in food. Also, if the food contains a chemically synthesized product that uses fossil fuel as a raw material, its ¹⁴ C concentration will be diluted compared to the current level. On the other hand, stable carbon isotope ratios in plants (δ ¹³
It is known that C) is greatly different between C3 plants and C4 plants and shows −22 ‰ to −32 ‰ and −10 ‰ to −16 ‰, respectively. Therefore, it is possible to estimate a C3 plant or a C4 plant from the δ ¹³ C value. In this study, we investigated the ¹⁴ C concentration and δ ¹³ C value of foods, and tried to estimate the identity of food ingredients from those values.

3. As sample foods, 9 commercially available edible oil samples (8 vegetable samples, 1 animal sample), 1 synthetic seasoning sample and 5 alcohols (3 beer samples, 2 sparkling liquor samples) were subjected to analysis. In order to estimate the ¹⁴ C concentration at the current level, 7 rice samples produced in 1999 grown in various parts of Japan were selected.

4. Evaluation The following table shows the ¹⁴ C concentration and δ ¹³ C value measurement results of 1999-produced rice, edible oil, synthetic seasonings, beer and happoshu.・ Radiocarbon concentration and stable carbon isotope ratio of rice produced in 1999: Fig. 6 ・ Radioactive carbon concentration and stable carbon isotope ratio of edible oil: Fig. 7 ・ Radioactive carbon concentration and stable carbon isotope ratio of synthetic seasoning: Fig. 8・ Stable carbon isotope ratio of beer and Happoshu: Fig. 9 ・ Component ratio of C3 or C4 plants constituting beer and Happoshu: Fig. 10

Regarding rice produced in 1999 and edible oil, the average value of ¹⁴ C concentration of rice produced in 1999 is 241.8 ± 2.
It was 6 mBq / (carbon-1 g), and the difference depending on the growing point was small (FIG. 6). The result of comparing this value with the current ¹⁴ C level and the ¹⁴ C concentration in the edible oil (FIG. 7),
Since 7 samples were at the same level, it seemed that the plant samples that had been growing until very recently were used as raw materials. 2 remaining
Among the samples, olive oil has a relatively high value, and squalane oil has a low value (226.3 mBq / (carbon-1
g)). It is estimated that olive oil was derived from plant samples that had grown several years ago. In addition, it was estimated that the ¹⁴ C concentration of squalane oil is due to the ¹⁴ C circulation in the environment where the deep-sea shark, which is the raw material, grew, rather than the possibility that fossil fuel was mixed.

The δ ¹³ C values of vegetable oils are all C3.
Clearly classified as a plant or C4 plant. Since it matches the raw material (C3 or C4) shown on the product label, it was confirmed that the C4 plant was not mixed with the C4 plant or the C4 plant was not mixed with the C3 plant. The δ ¹³ C value −21.0 ‰ of squalane oil seemed to be strongly influenced by the food habits of deep-sea sharks and the isotope fractionation in metabolic processes.
It is estimated that the edible oil used in this study did not contain chemically synthesized products derived from fossil fuels, and that it was not mixed with raw materials other than the labeled components, so it was judged that the displayed label was appropriate. To be done.

Regarding the synthetic seasoning, FIG. 8 shows the measurement results of one sample of the synthetic seasoning and the special grade reagent containing the main component thereof. Since the ¹⁴ C concentration of the synthetic seasoning is higher than that of the rice produced in 1999, it is presumed that it was synthesized from a plant that had grown before as a raw material.
Also, from the δ ¹³ C value, the plant is likely to be a C4 plant (corn or sugar cane) if it is a land plant. The ¹⁴ C concentration and δ ¹³ C value of the special grade reagent showed the same tendency as that of the synthetic seasoning. ^{From the 14} C concentration, the source of this special grade reagent is not fossil fuel. Further, since it is impossible to directly obtain this main component as a simple substance from nature, it is presumed that the C4 plant is used as a raw material.

Regarding alcohol, the difference between beer and Happoshu is the proportion of malt. Beer is malt occupying 67% or more of raw materials other than water,
Happoshu, on the other hand, is less than that. Some Happoshu have less than 25% malt. Figure 9 shows δ for beer and Happoshu.
^{It is a 13} C value. Beer shows values close to C3 plants, while Happoshu is close to C4 plants. It is expected that the proportion of auxiliary materials (hops, cornstarch, etc.) in Happoshu will increase as much as the amount of malt is reduced, and the δ ¹³ C value supports this. Δ ¹³ C value of C3 plants-
FIG. 10 shows the composition ratio of the raw materials (C3 or C4) of beer and Happoshu, assuming that 25 ‰ and −10 ‰ for C4 plants.

[0042]

EFFECTS OF THE INVENTION Since the present invention is based on the above-mentioned method, there is an effect that C3 plants or C4 plants in foods can be estimated or specified and source materials other than food labeling labels can be estimated or specified.

[Brief description of drawings]

FIG. 1 is a view showing a pretreatment vacuum line for measuring stable carbon isotope ratio.

FIG. 2 is a radiocarbon concentration map of atmospheric carbon dioxide collected around the power plant A.

FIG. 3 is a radiocarbon concentration diagram of carbon dioxide in the atmosphere collected around the power plant B.

FIG. 4 is a radiocarbon concentration map of carbon dioxide in the atmosphere collected around the C power plant.

FIG. 5 is a radiocarbon concentration map of atmospheric carbon dioxide collected in city D.

FIG. 6 is a radiocarbon concentration and stable carbon isotope ratio map of rice produced in 1999.

FIG. 7 is a radiocarbon concentration and stable carbon isotope ratio diagram of edible oil.

FIG. 8 is a radiocarbon concentration and carbon stable isotope ratio diagram of the synthetic seasoning.

FIG. 9 is a diagram showing stable carbon isotope ratios of beer and Happoshu.

FIG. 10 is a diagram showing the composition ratio of C3 or C4 plants composing beer and Happoshu.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takayoshi Nagano             2-47 Shiobara, Minami-ku, Fukuoka City Kyushu Electric Power             Research Institute, Inc. (72) Inventor Nobuaki Matsuoka             1-10-1 Matsukadai, Higashi-ku, Fukuoka City Foundation Law             Human Kyushu Environmental Management Association (72) Inventor Shinji Tawaki             1-10-1 Matsukadai, Higashi-ku, Fukuoka City Foundation Law             Human Kyushu Environmental Management Association (72) Inventor Hidehisa Kawamura             1-10-1 Matsukadai, Higashi-ku, Fukuoka City Foundation Law             Human Kyushu Environmental Management Association

Claims (2)

[Claims] 1. A method for recovering carbon in a sample food as carbon dioxide gas by a sealed tube combustion method, determining a carbon isotope ratio by a stable isotope ratio mass spectrometer, and comparing it with the carbon isotope ratio of a source material. A method for identifying raw materials in foods characterized by. 2. The method for identifying a raw material in food according to claim 1, wherein the carbon isotope ratio in the sample food is indicated by the deviation from ¹³ C / ¹² C of the international standard sample in thousandths.