Method for identifying the origin of pangasius based on stable isotopes

Abstract

The present invention discloses a method for identifying the origin of basa fish based on stable isotopes, comprising the steps of constructing a sample library of basa fish from the Mekong River, separating and obtaining the fleshy part of each sample, obtaining the tip of the fishbone, and removing the base of the fishbone where the fishbone is connected to the fishbone to obtain the fishbone; and detecting the δ 13 C value, according to the detected fishbone δ 13 C、fishbone δ 13 C and fleshy part δ 13 C respectively constructed the 13 C isotope database, obtain the fishbone δ 13 The 95% confidence interval of C, the standard interval of η2, and the δ 13 C value, and obtain the η2 value of the Basa fish to be tested. If the test value is consistent with the fish bone δ 13 If the 95% confidence interval of C and the standard interval of η2 are met, the origin of the sample is determined to be the Mekong River. Otherwise, the sample to be tested is determined to be falsely labeled. Compared with traditional detection methods, the present invention has high efficiency and accurate results.

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 counterfeit Basa fish have appeared on the market in recent years.

[0004] Fake basa fish is of inferior quality, with a less tender texture and a slightly rougher texture, lacking the delicious flavor of authentic basa fish. Fake basa fish also has reduced nutritional value. Hormones and other substances may be added during the breeding process, resulting in poor nutritional value. In contrast, authentic basa fish is rich in protein, unsaturated fatty acids, and various 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 country are pretending to be Basa fish farmed in the Mekong River, which has seriously impacted 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 counterfeiting the origin of basa fish in the market.

[0008] To achieve the above-mentioned object, the present invention proposes a method for identifying the origin of pangasius based on stable isotopes, which is characterized by comprising:

[0009] Establish a sample library of Pangasius spp. from the Mekong River;

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

[0011] Obtain the tip of the fishbone and remove the base of the fishbone where the fishbone is connected to the fishbone to obtain the fishbone;

[0012] Detection of the δ 13 C value;

[0013] According to the detected fishbone δ 13 C、fishbone δ 13 C and fleshy part δ 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 tested Pangasius 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] Obtain the η2 value of the Basa fish to be tested, and compare the η2 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 falsely identified.

[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 standard interval of η2 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 the 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 spinal 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 where the fishbone is connected to the fishbone to obtain the fishbone; detect the δ 13 C value; according to the detected fishbone δ 13 C、fishbone δ 13 C and fleshy part δ 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 the fish bones of the tested Pangasius 13 C value, and its detection value is compared with 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 95% confidence interval of the fishbone δ 13 If the 95% confidence interval of C is less than 0.05, the sample to be tested is judged to be a false identification;

[0024] The η2 value of the pangasius to be tested is obtained and compared with the standard range of η2. If it meets the standard range, the origin of the pangasius is determined to be the Mekong River. Otherwise, the sample to be tested is determined to be falsely labeled. Compared with traditional detection methods, the present invention is highly efficient and produces 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 following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any creative work.

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

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

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

[0029] Figure 4 The meat quality of basa fish samples from basa fish farming areas in seven provinces is shown in the figure. 13 C and fishbone δ 13 Linear relationship graph of C;

[0030] Figure 5 The meat quality of basa fish samples from basa fish farming areas in seven provinces is shown in the figure. 13 C and fishbone δ 13 Linear relationship graph of C;

[0031] Figure 6 The δ of fishbone of basa fish samples from basa fish farming areas in seven provinces 13 C and fishbone δ 13 Linear relationship graph of C;

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

[0034] Figure 9 The fishbone δ of the basa fish sample in the first basa fish farming area in the Mekong River 13 C and fishbone δ 13 Linear relationship graph of C;

[0035] Figure 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 graph of C;

[0036] Figure 11 The flesh of the Pangasius sample from the second Pangasius aquaculture area in the Mekong River 13 C and fishbone δ 13 Linear relationship graph of C;

[0037] Figure 12 The fishbone δ of the basa fish sample in the second basa fish farming area of the Mekong River 13 C and fishbone δ 13 Linear relationship graph of C;

[0038] Figure 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 graph of C;

[0039] Figure 14 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 graph of C;

[0040] Figure 15 The fishbone δ of the basa fish sample in the third basa fish farming area of the Mekong River 13 C and fishbone δ 13 Linear relationship graph of C;

[0041] Figure 16 This is a comparison chart of the η2 results of Mekong River Pangasius and Pangasius from seven provinces in China;

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

[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall 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 they must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0045] Basa fish are scaleless fish with two different body colors: one with a bluish-black back and a white belly, and the other with a pinkish-white back and a white belly. Basa fish are an important freshwater aquaculture species in Southeast Asian countries, particularly Vietnam.

[0046] Basa fish is a white, tender fish that is rich in nutrients, including protein, vitamin A, calcium, and a unique belly fat mass. It has a high development and utilization value. Therefore, Basa fish is gradually gaining popularity in markets around the world, especially in China, where the market prospects are very promising.

[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 output of basa fish in these regions even exceeds that of Vietnam.

[0048] Compared to other fish, basa fish require relatively demanding farming conditions. For example, the ideal water temperature for basa fish is 22-32°C. Below 20°C, their growth rate slows, and below 13°C, they can suffer frostbite or even die. This means that low water temperatures severely impact basa fish production. Therefore, in regions like Hunan, Jiangxi, and Guangxi, basa fish can only be farmed during relatively high temperatures during the few seasons. The Mekong River, however, due to its tropical and subtropical location, maintains relatively high temperatures year-round, making it particularly suitable for basa fish farming. Furthermore, basa fish raised in the Mekong River are farmed in live water, requiring no hormones. The quality of the fish is higher than that of fish raised in other regions. These factors contribute to the higher price of basa fish farmed in the Mekong River compared to those farmed in other regions.

[0049] Since prices vary depending on the 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 samples and 34 water samples through three years of sampling (excluding the samples from the Mekong River, where a total of 135 Pangasius 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 on the market.

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

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

[0054]

[0055]

[0056]

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

[0058] Establish a sample library of Pangasius spp. from the Mekong River;

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

[0060] Obtain the tip of the fishbone and remove the base of the fishbone where the fishbone is connected to the fishbone to obtain the fishbone;

[0061] Detection of the δ 13 C value;

[0062] According to the detected fishbone δ 13 C、fishbone δ 13 C and fleshy part δ 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 tested Pangasius 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] Obtain the η2 value of the Basa fish to be tested, and compare the η2 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 falsely identified.

[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 digested ingredients, one is plants and the other is meat. The process of meat digestion and metabolism is different from that of plants. The δ 13 There are also significant differences in C. During 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 time, and metabolic process of C are all different.

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

[0069] Table 1 δ of fish belly, fish back and fish 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 δ 13 The detection values of C are basically consistent.

[0073] The bony part of Basa fish mainly includes the spine (fishbone) and fishbone. The fishbone is connected to the fishbone, but the forming 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 accumulated during the entire breeding cycle of Basa 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 tip of the basa fish bone, the main base of the basa fish bone (5mm to 10mm 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 base of the main trunk 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] From Table 3, we can see that even for samples from the same batch, 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 is adjacent to the spine and is also connected to the fishbone, it is difficult to completely 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 part is lower and the outer edge part is higher.

[0084] Table 4: 7 provinces 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 for C vary greatly due to regional factors. This is mainly due to the feed sources of pangasius, as well as the influence of latitude and longitude, altitude, humidity, and rainfall in each region.

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

[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 interaction between photosynthesis pathways and environmental factors. 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 tend to fix carbon dioxide with a relatively light carbon isotope under the catalysis of ribulose bisphosphate carboxylase, 12 CO2 is absorbed, and their 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 The 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‰. In addition, the δ 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 primarily consists of fresh fish, soybean meal, cornmeal, corn starch, soybean oil, bone meal, fish meal, vitamins, and minerals. This type of feed is commonly used in Hubei, Hunan, Jiangxi, and Guangxi. Fresh fish is a crucial component of basa fish feed, and can be adjusted based on the price and palatability of fresh carp, crucian carp, grass carp, and other species. The ratio of soybean meal and cornmeal to fresh fish must be strictly adhered to, typically in a ratio of 1:2:2. Corn starch is used to increase the viscosity and gelatinization properties of the feed, and its use should not exceed 5% of the total ingredients. Bone meal and fish meal are used to supplement minerals and protein deficiencies in the feed, but their addition should be limited, generally not exceeding 10% of the total ingredients.

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

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

[0095] It can be seen from this feed that its composition includes 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 powder, corn flour, 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: mixed feed made from a variety of raw materials (its composition is complex and irregular), which 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 (fleshy part) in Table 4, the 95% confidence interval can be obtained from the normal distribution diagram: mean ± 1.96 × standard deviation, -14.75‰ to -11.39‰. Compared with the data of seven provinces in Table 1, it is found that the δ 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‰ to -8.74‰. Comparing with the data of seven provinces outside the Mekong River, it was found that A3 of Yunnan, C3 of Hubei, D3 and E3 of Hainan were 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 (fish bones) in Table 2, the 95% confidence interval can be obtained from the normal distribution diagram: mean ± 1.96 × standard deviation, -10.17‰ to -7.07‰. Compared with the data of seven provinces outside the Mekong River, Yunnan A3 samples, 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 an excessively high probability of false detection.

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

[0107] Table 5 δ of pangasius samples from seven provinces 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 among the samples from the seven provinces, fishbone δ 13 C and fleshy part δ 13 The linear relationship between them satisfies y=0.9271x-6.7287, R 2 =0.739;

[0121] Fishbone δ 13 C and fleshy part δ 13 The linear relationship between them satisfies y=0.8211x-6.2675, R 2 =0.8399;

[0122] Fishbone δ 13 C and fishbone δ 13 The linear relationship between them satisfies 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 The linear relationship between them satisfies y=0.5445x-8.0971, R 2 =0.3939;

[0123] The first aquaculture area in the Mekong River, fishbone δ13 C and fleshy part δ 13 The linear relationship between them satisfies 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 The linear relationship between them satisfies 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 The linear relationship between them satisfies 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 The linear relationship between them satisfies 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 The linear relationship between them satisfies 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 The linear relationship between them satisfies y=0.6386x-7.7781, R 2 =0.4967;

[0129] The third aquaculture area in the Mekong River, fishbone δ 13 C and fleshy part δ 13 The linear relationship between them satisfies 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 The linear relationship between them satisfies 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 13The 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 y 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=fishbone δ 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 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 in China. However, it is worth mentioning that please refer to Figure 16 It can also be seen from the figure that the range of η2 in the seven provinces 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 identification of Mekong River Basa fish can be more accurately carried out according to the value of η2.

[0136] Continuing to refer to Table 4, although the above conclusions reveal that: by detecting the δ 13 The 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 13C 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 transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application 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: Establish a sample library of Pangasius spp. from the Mekong River; Separate and obtain the fleshy part of each sample; Obtain the tip of the fishbone and remove the base of the fishbone where the fishbone is connected to the fishbone to obtain the fishbone; Detection of the δ 13 C value; the fish bone is taken from the spinal part corresponding to two adjacent fish bones, and the length of the spine tip is 2mm~6mm; According to the detected fishbone δ 13 C、fishbone δ 13 C and fleshy part δ 13 C respectively constructed the 13 C isotope database; Get the fishbone δ 13 95% confidence interval for C, and the standard interval for η2, where η2 = fishbone δ 13 C / fleshy partδ 13 C; Detection of the fish bones of the tested Pangasius 13 C value, and its detection value is compared with the fishbone δ 13 The 95% confidence interval of C is compared. If it meets the fishbone δ 13 C, then proceed to the next step of testing. If it does not meet the requirements of the fishbone δ 13 If the 95% confidence interval of C is less than 0.05, the sample to be tested is judged to be a false identification; Obtain the η2 value of the Basa fish to be tested, and compare the η2 with the standard range of η2, which is (0.73, 0.79). 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 falsely identified.

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

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

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