Method for identifying producing area of Basa fish based on stable isotope

Abstract

The invention discloses a method for identifying the producing area of Basa fishes based on stable isotopes, which comprises the following steps: constructing a Mekong Basa fish sample library, separating to obtain the meat part of each sample, obtaining the tip part of a fishbone, and removing the fishbone base part of the fishbone connected to the fishbone to obtain the fishbone; the method comprises the following steps: detecting delta 13C values of a fishbone tip part, a fishbone part and a meat part, respectively constructing 13C isotope databases of the Basa fish according to the detected delta 13C of the fishbone, the delta 13C of the fishbone and the delta 13C of the meat part, obtaining 95% confidence interval of the delta 13C of the fishbone and a standard interval of eta 2, detecting the delta 13C value of the fishbone of the Basa fish to be detected, and obtaining the eta 2 value of the Basa fish to be detected, and if the detection value conforms to 95% confidence interval of delta 13C of the fishbone and standard interval of eta 2, judging that the origin place is the Mekong, otherwise, judging that the sample to be detected is a false identifier. Compared with a traditional detection method, the method is high in efficiency and accurate in result.

Description

Technical Field

[0001] The present invention relates to the technical field of origin tracing, and in particular to a method for identifying the origin of basa fish based on stable isotopes. Background Art

[0002] Basa fish is an important freshwater aquaculture species in Southeast Asian countries and a unique high-quality economic fish in the Mekong River basin.

[0003] Due to the high economic benefits of Basa fish, a large number of fake Basa fish have appeared on the market in recent years.

[0004] Fake Basa fish is of poor quality, the meat is not tender enough, the taste is slightly rough, and the taste is not as delicious as the real Basa fish. The nutritional value of fake Basa fish will be reduced. Hormones and other substances may be added during the breeding process, resulting in poor content. In contrast, real Basa fish is rich in protein, unsaturated fatty acids and multiple vitamins, which are beneficial to human health.

[0005] Fake Basa fish is mainly a geographical fraud (origin fraud), that is, Basa fish farmed outside the province is pretending to be Basa fish farmed in the Mekong River, which has a serious impact on the Basa fish market.

[0006] Since the appearance and taste of Basa fish farmed outside the province are almost the same as those farmed in the Mekong River, it is difficult to distinguish the real ones from the fake ones. Summary of the invention

[0007] The main purpose of the present invention is to provide a method for identifying the origin of Basa fish based on stable isotopes, aiming to solve the problem of fake origin of Basa fish in the market.

[0008] To achieve the above object, the method for identifying the origin of pangasius based on stable isotopes proposed in the present invention is characterized by comprising:

[0009] Construct a sample library of pangasius from the Mekong River;

[0010] Separate and obtain the fleshy part of each sample;

[0011] The tip of the fish bone is obtained, and the base of the fish bone where the fish bone is connected to the fish bone is removed to obtain the fish bone;

[0012] Detection of the δ of the fishbone tip, fish bone and meat 13 C value;

[0013] According to the detected fishbone δ 13 C. Fishbone 13 C and fleshy partδ 13 C respectively constructed the 13 C isotope database;

[0014] Get the fishbone δ13 95% confidence interval for C, and the standard interval for η2, where η2 = fishbone delta 13 C / fleshy partδ 13 C;

[0015] Detection of the fish bones of the pangasius to be tested 13 C value, and compare its detection value with the confidence interval. If it meets the confidence interval, it will proceed to the next step of detection. If it does not meet the confidence interval, it will be determined that the sample to be tested is a false identification;

[0016] The η2 value of the Basa fish to be tested is obtained, and the η2 is compared with the standard range of η2. If it meets the standard range of η2, its origin is determined to be the Mekong River, otherwise the sample to be tested is determined to be a false mark.

[0017] In one embodiment, the fishbone δ 13 The 95% confidence interval of C is -10.17‰ to -7.07‰.

[0018] In one embodiment, the η2 standard interval is (0.73, 0.79).

[0019] In one embodiment, the number of samples in the Mekong River Pangasius sample library is no less than 108.

[0020] In one embodiment, the fishbone is taken from the bone tip, and the fish bone is taken from the spine of Pangasius.

[0021] In one embodiment, the length of the thorn tip is 2 mm to 6 mm.

[0022] In one embodiment, the fish bones are taken from the vertebral parts corresponding to two adjacent fish bones.

[0023] The technical solution of the present invention is to construct a sample library of Mekong River basa fish; separate and obtain the fleshy part of each sample; obtain the tip of the fishbone, and remove the base of the fishbone connected to the fishbone to obtain the fishbone; detect the δ 13 C value; according to the detected fishbone δ 13 C. Fishbone 13 C and fleshy partδ 13 C respectively constructed the 13 C isotope database; obtain the fishbone δ 13 95% confidence interval for C, and the standard interval for η2, where η2 = fishbone delta 13 C / fleshy partδ 13 C; Detection of fish bones of the pangasius to be tested 13 C value, and its detection value and the fishbone δ 13The 95% confidence interval of C is compared, and if it meets the fishbone δ 13 C, then proceed to the next step of testing. If it does not meet the fishbone δ 13 If the confidence interval of C is 95%, the sample to be tested is judged to be a false label;

[0024] The η2 value of the pangasius to be tested is obtained, and the η2 is compared with the standard interval of the η2. If it meets the standard interval of the η2, the origin of the pangasius is determined to be the Mekong River, otherwise the sample to be tested is determined to be a false identification. Compared with the traditional detection method, the present invention has high efficiency and accurate results. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0026] Figure 1 The fleshy part of the Mekong River Pangasius 13 Normal distribution plot of C;

[0027] Figure 2 The fishbone of the Mekong River Pangasius 13 Normal distribution plot of C;

[0028] Figure 3 The fish bone of the Mekong River Pangasius 13 Normal distribution plot of C;

[0029] Figure 4 The meat quality of basa fish samples from basa fish farming areas in seven provinces (autonomous regions) is shown in Figure δ 13 C and fishbone δ 13 Linear relationship diagram of C;

[0030] Figure 5 The meat quality of basa fish samples from basa fish farming areas in seven provinces (autonomous regions) is shown in Figure δ 13 C and fishbone delta 13 Linear relationship diagram of C;

[0031] Figure 6 The fishbone δ of basa fish samples in basa fish farming areas in seven provinces (autonomous regions) 13 C and fishbone δ 13 Linear relationship diagram of C;

[0032] Figure 7 The flesh of the pangasius sample from the first pangasius aquaculture area in the Mekong River 13C and fishbone δ 13 Linear relationship diagram of C;

[0033] Figure 8 The flesh of the pangasius sample from the first pangasius aquaculture area in the Mekong River 13 C and fishbone delta 13 Linear relationship diagram of C;

[0034] Fig. 9 The fishbone δ of the pangasius sample in the first pangasius aquaculture area in the Mekong River 13 C and fishbone δ 13 Linear relationship diagram of C;

[0035] Fig.10 The flesh of the pangasius sample from the first pangasius aquaculture area in the Mekong River 13 C and fishbone δ 13 Linear relationship diagram of C;

[0036] Fig.11 The flesh of the pangasius sample from the second pangasius aquaculture area in the Mekong River 13 C and fishbone delta 13 Linear relationship diagram of C;

[0037] Fig.12 The fishbone δ of the pangasius sample from the second pangasius aquaculture area in the Mekong River 13 C and fishbone δ 13 Linear relationship diagram of C;

[0038] Fig.13 The meat quality of the pangasius sample from the third pangasius aquaculture area in the Mekong River 13 C and fishbone δ 13 Linear relationship diagram of C;

[0039] Fig.14 The meat quality of the pangasius sample from the third pangasius aquaculture area in the Mekong River 13 C and fishbone delta 13 Linear relationship diagram of C;

[0040] Fig.15 The fishbone δ of the pangasius sample from the third pangasius aquaculture area in the Mekong River 13 C and fishbone δ 13 Linear relationship diagram of C;

[0041] Fig.16 This is a comparison chart of the results of η2 of the Mekong River Basa fish and Basa fish from seven provinces (autonomous regions) in China;

[0042] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0045] Basa fish is a scaleless fish with no scales on its body. It has two body colors, one with a blue-black back and a white belly, and the other with a pink-white back and a white belly. Basa fish is an important freshwater aquaculture species in Southeast Asian countries, especially Vietnam.

[0046] As Basa fish is white and tender, rich in nutrients, rich in protein, vitamin A, calcium and other elements, as well as unique abdominal fat, it has a high development and utilization value. Therefore, Basa fish is gradually welcomed by the world market, especially in China, where the market prospect of Basa fish is very great.

[0047] In recent years, large-scale basa fish breeding bases have emerged in China, such as Hunan, Jiangxi, Guangxi, Guangdong, Yunnan and other regions. The annual production of basa fish even exceeds that of Vietnam.

[0048] Compared with other types of fish, the breeding conditions of Basa fish are relatively harsh. For example, the water temperature suitable for the growth of Basa fish is 22-32℃. When it is lower than 20℃, its growth rate slows down as the water temperature decreases. When the water temperature is lower than 13℃, Basa fish will be frostbitten or die directly. That is, when the water temperature is low, the production of Basa fish is seriously affected. Therefore, in Hunan, Jiangxi, Guangxi and other places, Basa fish can only be farmed in a few seasons when the temperature is relatively high. The Mekong River is located in the tropical and subtropical regions, and its temperature remains at a high level all year round, which is particularly suitable for breeding Basa fish. Moreover, it can be farmed at all four levels of the year. In addition, the Basa fish in the Mekong River is farmed in live water, and no hormones are required during breeding. The quality of the farmed Basa fish is higher than that in other regions. Combining the above factors, the price of Basa fish farmed in the Mekong River is higher than that of Basa fish farmed in other regions.

[0049] Since prices vary depending on the place of origin, some unscrupulous merchants use some means to falsify the origin of Basa fish in order to gain unfair profits, which has seriously impacted the Basa fish market.

[0050] Based on this, this application uses stable isotope analysis to derive a set of methods that can distinguish the origin of Basa fish, thereby protecting the Basa fish market, safeguarding the interests of regular merchants, and protecting the rights and interests of consumers.

[0051] This method was used to obtain 34 pangasius fish samples and 34 water samples through three years of sampling (excluding samples from the Mekong River, where a total of 135 pangasius fish samples and 135 water samples were collected in the three years). 13 C abundance was tested to form a relatively large database, and the rules were summarized from the database to find a method to identify false origin labeling in the market.

[0052] Please refer to the table below for sample information

[0053] Table 1 Sampling information of eleven basa fish breeding areas

[0054]

[0055]

[0056]

[0057] The method for identifying the origin of pangasius based on stable isotopes proposed in the present invention comprises:

[0058] Construct a sample library of pangasius from the Mekong River;

[0059] Separate and obtain the fleshy part of each sample;

[0060] The tip of the fish bone is obtained, and the base of the fish bone where the fish bone is connected to the fish bone is removed to obtain the fish bone;

[0061] Detection of the δ of the fishbone tip, fish bone and meat 13 C value;

[0062] According to the detected fishbone δ 13 C. Fishbone 13 C and fleshy partδ 13 C respectively constructed the 13 C isotope database;

[0063] Get the fishbone δ 13 95% confidence interval for C, and the standard interval for η2, where η2 = fishbone delta 13 C / fleshy partδ 13 C;

[0064] Detection of the fish bones of the pangasius to be tested 13C value, and compare its detection value with the confidence interval. If it meets the confidence interval, it will proceed to the next step of detection. If it does not meet the confidence interval, it will be determined that the sample to be tested is a false identification;

[0065] The η2 value of the Basa fish to be tested is obtained, and the η2 is compared with the standard range of η2. If it meets the standard range of η2, its origin is determined to be the Mekong River, otherwise the sample to be tested is determined to be a false mark.

[0066] Specifically, during the growth of Basa fish, the 13 C is mainly affected by its ingredients. After being eaten by Basa fish, the ingredients are digested in the esophagus of Basa fish. There are two main types of ingredients to be digested, one is plants and the other is meat. The process of meat digestion and metabolism is different from that of plants. The δ 13 C also has a big difference. In the metabolic process, the metabolic fractionation of the two 13 C fractionation) also has great differences, which ultimately leads to the 13 C is not very stable.

[0067] During the growth of Basa fish, the δ 13 There are also significant differences in C because the two 13 The enrichment process, enrichment duration, and metabolic process of C are all different.

[0068] After the experiment, the belly, back and tail of the fleshy part of the basa fish were taken and their δ 13 C value:

[0069] Table 1 δ of belly, back and tail of some samples 13 The detection value of C

[0070]

[0071]

[0072] From the above table, we can see that the fish belly, fish back, and fish tail δ 13 The difference of the detection value of C is within ±0.1, which is very small, that is, the difference between the belly, back and tail of the basa fish is 13 The detection values ​​of C are basically the same.

[0073] The bone part of Basa fish mainly includes the spine (fishbone) and fishbone. The fishbone is connected to the fishbone, but the formation process of the fishbone and the fishbone, as well as its δ 13 The enrichment degree of C is different.

[0074] As for fish bones, they retain the nutrients that are enriched during the entire breeding cycle of Pangasius fish. 13 C, and the length of fish bones varies greatly with the breeding time of basa fish, especially the tip of the bone, which is formed later and has a greater impact on δ 13 The enrichment of C was lower than that in the fish bone part.

[0075] After the test, the fish bones and fish bones of basa fish were taken, specifically the 2mm to 6mm basa fish bone tip, the main trunk base of basa fish bone (5mm to 10mm away from the connecting fish bone), and the fish bone (the corresponding spine part between two adjacent fish bones), and the δ 13 C Value

[0076] Table 2 Fish bones and fishbone δ of some samples 13 The detection value of C

[0077]

[0078] * A1-H2 are average values, and N2 is a single sample value

[0079] Table 3 The main base of the same batch of fish bones δ 13 The detection value of C

[0080]

[0081] As can be seen from Table 2, the δ 13 C value relative to the spine delta 13 The C value has obvious depletion phenomenon; the δ 13 The C value is extremely unstable, and some data are close to the δ of the spine 13 C value, some data are close to the spike δ 13 C value, some data are between the two.

[0082] It can be seen from Table 3 that even for the same batch of samples, the δ 13 C value and spine delta 13 The C value is relatively stable, while the δ 13 The C value deviation is large and the stability is poor.

[0083] The reason may be due to the sample processing. Because the base of the fishbone borders the spine and is also connected to the fishbone, it is difficult to absolutely isolate the spine from the sample. During the pre-processing process, it may be disturbed by the spine, resulting in δ 13 The C value is unstable. Another possible cause is the base of the fishbone itself. 13 The distribution of C is uneven, for example, the central part 13 C is higher, the outer edge 13 C is lower, or the center is lower and the outer edge is higher.

[0084] Table 4: 7 provinces (autonomous regions) in China and the Mekong River 13 Isotope data table of C

[0085]

[0086]

[0087] *The fish bones in this table and the following tables are taken from the 2mm-6mm part of the bone tip

[0088] As can be seen from the table above, the δ 13 The data of C vary greatly due to geographical reasons. The main reasons are the feed sources of pangasius, as well as the influence of latitude and longitude, altitude, humidity and rainfall in different regions.

[0089] First, the impact of region and local cash crops on the composition of Pangasius feed is analyzed:

[0090] The composition of carbon isotope ratios in plants is closely related to the photosynthetic metabolic pathway of plants and is also affected by some environmental factors. 13 The C value is the result of the combined effects of photosynthesis pathways and environmental factors. In terrestrial plant tissues, 13 C / 12 The main reason for the change in C ratio is the difference in the way plants fix carbon dioxide. There are three ways for plants to fix carbon dioxide: C3 pathway, C4 pathway and Crassulacean acid metabolism (CAM) pathway. Because C3 plants prefer to use relatively light carbon isotopes under the catalysis of ribulose bisphosphate carboxylase, 12 CO2 is absorbed by 13 C / 12 C is relatively small, δ 13 The C value is relatively low, generally between -20‰ and -34‰. However, C4 plants do not have this bias. They have no selectivity for carbon dioxide absorption of various carbon isotopes, and the isotope fractionation effect is also very small. Compared with C4 plants, 13 C / 12 C ratio is relatively large, δ 13 The value of C is generally between -9‰ and -15‰, but for most common C4 plants, δ 13 The C value is between -9‰ and 12‰. 13 C generally comes directly or indirectly from plants, and the δ 13 C has been fractionated, so the δ 13 C is relatively high. Taking C3 plants as an example, if the δ 13The C value is -25‰, so the δ 13 The C value may be -16‰.

[0091] For Basa fish feed, there are mainly the following types:

[0092] One type of feed mainly includes fresh fish meat, soybean meal, corn flour, corn starch, soybean oil, bone meal, fish meal, vitamins and minerals. This type of feed is commonly used in Hubei, Hunan, Jiangxi, Guangxi and other places. Here, fresh fish meat is an important component of Basa fish feed, which can be formulated and used according to the price and palatability of fresh carp, crucian carp, grass carp and so on. The mixing ratio of soybean meal and corn flour with fresh fish meat should be strictly in accordance with the scientific ratio, generally fresh fish meat: soybean meal: corn flour = 1:2:2. Corn starch is to increase the viscosity and gelatinization of the feed, and the amount should not exceed 5% of the total raw materials. Bone meal and fish meal are to supplement the minerals and proteins lacking in the feed, but the amount added should not be excessive, generally not exceeding 10% of the total raw materials.

[0093] It can be seen from this feed that its composition is complex, with meat, C3 plants, and C4 plants. 13 C may fluctuate widely.

[0094] Another type of feed is mainly composed of fish meal, soybean meal, bran, fish oil, amino acids, vitamins and minerals. This type of feed is commonly used in Guangxi, Guangdong, Hainan and other regions. The specific ratio is: fish meal: 35%, soybean meal: 25%, bran: 15%, fish oil: 10%, amino acids: 5%, vitamins and minerals: 5%, other additives: 5%.

[0095] From this feed, we can see that it is composed of C3 plants, meat and minerals. 13 The fluctuation range of C is also relatively large.

[0096] Another type of feed is mainly live bait: small fish, shrimp, copepods, silkworms and other active baits, which are rich in protein, fat and vitamins.

[0097] It can be seen from this feed that its substance is mainly meat, so 13 The fluctuation of C is relatively small, possibly between -7‰ and -12‰.

[0098] Another type of feed is mainly dry feed: granular feed made by mixing dry fish meal, soybean cake meal, corn meal, soybean oil, fish oil and vitamins.

[0099] It can be seen from this feed that its composition is mainly meat, C3 plants and C4 plants, and its δ 13 C has a relatively large fluctuation range.

[0100] Another type of mixed feed: a mixed feed made from a variety of raw materials (whose composition is complex and irregular), is also more beneficial to the growth and development of Basa fish.

[0101] Since this feed is relatively complex, its source may be local food residues or local plants, etc., so its δ 13 C depends directly on local crops.

[0102] See also Figure 1 , Figure 1 From the data of Mekong River N1, N2 and N3 in Table 4 (fleshy part), the 95% confidence interval can be obtained from the normal distribution diagram: mean ± 1.96 × standard deviation, -14.75‰ ~ -11.39‰. Compared with the data of seven provinces (autonomous regions) in Table 1, it is found that the δ of Guangxi F1-G3 samples is 13 The C(‰) value is also within this range, with an accuracy of 79.4%.

[0103] See also Figure 2 , Figure 2 From the data groups of N1, N2 and N3 of the Mekong River in Table 2 (fishbone), the 95% confidence interval can be obtained from the normal distribution diagram: mean ± 1.96 × standard deviation, -11.44‰ ~ -8.74‰. By comparing the data of seven provinces (autonomous regions) outside the Mekong River, it is found that A3 of Yunnan, C3 of Hubei, D3 and E3 of Hainan are also within this range, with an accuracy rate of 88.23%.

[0104] See also Figure 3 , Figure 3 From the Mekong River N1, N2 and N3 data groups in Table 2 (fishbone), the 95% confidence interval can be obtained from the normal distribution diagram: mean ± 1.96 × standard deviation, -10.17‰ ~ -7.07‰. Compared with the data of seven provinces (autonomous regions) outside the Mekong River, the Yunnan A3 sample, Hainan D3, and Hainan E3 are also within this range, with an accuracy rate of 91.18%.

[0105] Although the accuracy of the above three comparison methods gradually increases and the highest value can reach more than 90%, 90% is too low for the identification of the origin of Basa fish and the accuracy rate does not meet the standard, which will lead to a too high probability of false detection.

[0106] In view of this, in order to further calculate the δ 13 The data of C are compiled from the above-mentioned breeding areas and the data of N1 (38 samples), N2 (42 samples), and N3 (55 samples) of the Mekong River:

[0107] Table 5 δ of Basa fish samples in seven provinces (autonomous regions) 13 C(‰) value

[0108]

[0109]

[0110] Table 6 δ of the Mekong River N1 sample group 13 C(‰) related data table

[0111]

[0112]

[0113] Table 7 δ of the Mekong River N2 sample group 13 C(‰) related data table

[0114]

[0115]

[0116]

[0117] Table 8 δ of the Mekong River N3 sample group 13 C(‰) related data table

[0118]

[0119]

[0120] Please refer to Tables 6-8, and Figure 4-Figure 6 , it can be seen that in the samples of the seven provinces (autonomous regions), fishbone δ 13 C and fleshy part δ 13 C, the two satisfy y = 0.9271x-6.7287, R 2 =0.739;

[0121] Fishbone δ 13 C and fleshy part δ 13 C, the two satisfy y = 0.8211x-6.2675, R 2 =0.8399;

[0122] Fishbone 13 C and fishbone delta 13 C, the two satisfy y = 1.1631x-0.1675, R 2 =0.9337 The first aquaculture area in the Mekong River, fish bone δ 13 C and fleshy part δ 13 C, the two satisfy y = 0.5445x-8.0971, R 2 =0.3939;

[0123] The first aquaculture area in the Mekong River, fishbone delta 13 C and fleshy part δ 13 C, the two satisfy y = 1.2399x-0.5487, R 2 =0.9544;

[0124] The first aquaculture area in the Mekong River, fish bone δ 13 C and thorn δ 13 C, the two satisfy y = 0.398x-6.304, R 2 =0.339;

[0125] The second aquaculture area in the Mekong River, fish bone δ 13 C and fleshy part δ 13 C, the two satisfy y = 1.3608x-1.1754, R 2 =0.9377;

[0126] The second aquaculture area in the Mekong River, fishbone δ 13 C and fleshy part δ 13 C, the two satisfy y = 1.2147x-0.7975, R 2 =0.9381;

[0127] The second aquaculture area in the Mekong River, fish bone δ 13 C and thorn δ 13 C, the two satisfy y = 1.3608x-1.1754, R 2 =0.9377;

[0128] The third aquaculture area in the Mekong River, fish bone δ 13 C and fleshy part δ 13 C, the two satisfy y = 0.6386x-7.7781, R 2 =0.4967;

[0129] The third aquaculture area in the Mekong River, fishbone delta 13 C and fleshy part δ 13 C, the two satisfy y = 1.0473x-2.5556, R 2 =0.7716;

[0130] The third aquaculture area in the Mekong River, fish bone δ 13 C and thorn δ 13 C, the two satisfy y = 0.5214x-5.7534, R 2 =0.4707;

[0131] From the above four groups of data, it can be seen that the best linear relationship is fishbone δ 13 C and fleshy part δ 13 The linear relationship of C is relatively good in the Mekong River aquaculture area, and R 2 They are 0.9544, 0.9381, and 0.7716 respectively. If R 2 Above 0.99, it means that the linear correlation is very good, and a pair of data in the sample has a good coupling with the linear relationship (the coupling coefficient is above 0.9, taking y = 1.2399x-0.5487, as an example, a pair of data x a and b , if 0.9≤(1.2399x a -0.5487) / y b ≤1.11), it can be judged that its production area is from the Mekong River, otherwise it can be judged that its production area is not the Mekong River.

[0132] Tables 5-8 were summarized, and the δ 13 The values ​​of C(‰) and their correlations, where:

[0133] η1=fishboneδ 13 C(‰) / fleshy partδ 13 C(‰);η2=fishboneδ 13 C(‰) / fleshy partδ 13 C(‰);η3=fishboneδ 13 C(‰) / fishboneδ 13 C(‰);

[0134] The range of η1 in the seven provinces (autonomous regions) in China is (0.43, 0.81), the range of η2 is (0.51, 0.89), and the range of η3 is (0.72, 0.96).

[0135] The range of η1 for the Mekong River is (0.51, 0.75), the range of η2 is (0.73, 0.79), and the range of η3 is (0.67, 0.99). The range of η values ​​for the Mekong River overlaps with the range of η values ​​for seven provinces (autonomous regions) in China. However, it is worth mentioning that please refer to Fig.16 It can also be concluded from the figure that the range of η2 in the seven provinces (autonomous regions) in China is mainly concentrated in two intervals, namely: (0.51, 0.71) and (0.80, 0.89), and the η2 value of the Mekong River fish samples is exactly between these two intervals. Based on this, the Mekong River Basa fish can be identified more accurately according to the value of η2.

[0136] Continuing to refer to Table 4, although the above conclusions reveal that: by detecting the δ 13The value of C and η2 can effectively determine the origin of Basa fish; however, both factors are directly or indirectly affected by δ 13 C, once δ 13 C changes significantly, and some Pangasius from foreign origins may be detected as originating from the Mekong River.

[0137] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for identifying the origin of pangasius based on stable isotopes, characterized in that: include: Construct a sample library of pangasius from the Mekong River; Separate and obtain the fleshy part of each sample; The tip of the fish bone is obtained, and the base of the fish bone where the fish bone is connected to the fish bone is removed to obtain the fish bone; Detection of the δ of the fishbone tip, fish bone and meat 13 C value; According to the detected fishbone δ 13 C. Fishbone 13 C and fleshy partδ 13 C respectively constructed the 13 C isotope database; Get the fishbone δ 13 The 95% confidence interval for C and the standard interval for η2, where η 2＝ Fishbone δ 13 C / fleshy partδ 13 C; Detection of the fish bones of the pangasius to be tested 13 C value, and its detection value and the fishbone δ 13 The 95% confidence interval of C is compared, and if it meets the fishbone δ 13 C, then proceed to the next step of testing. If it does not meet the fishbone δ 13 If the confidence interval of C is 95%, the sample to be tested is judged to be a false label; The η2 value of the Basa fish to be tested is obtained, and the η2 is compared with the standard range of η2. If it meets the standard range of η2, its origin is determined to be the Mekong River, otherwise the sample to be tested is determined to be a false mark.

2. The method for identifying the origin of pangasius based on stable isotopes according to claim 1, characterized in that: The fishbone 13 The 95% confidence interval of C is -10.17‰ to -7.07‰.

3. The method for identifying the origin of pangasius based on stable isotopes according to claim 2, characterized in that: The η2 standard interval is (0.73, 0.79).

4. The method for identifying the origin of pangasius based on stable isotopes according to claim 1, characterized in that: The number of samples in the Mekong River Pangasius sample library constructed is no less than 108.

5. The method for identifying the origin of pangasius based on stable isotopes according to claim 1, characterized in that: The fishbone is taken from the tip of the bone, and the fishbone is taken from the spine of the Pangasius.

6. The method for identifying the origin of pangasius based on stable isotopes according to claim 5, characterized in that: The length of the thorn tip is 2 mm to 6 mm.

7. The method for identifying the origin of pangasius based on stable isotopes according to claim 5, characterized in that: The fish bones are taken from the vertebral parts corresponding to two adjacent fish bones.

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