CN117664689A - Method for analyzing or identifying sweet potato/tapioca starch based on nitrogen stable isotope - Google Patents
Method for analyzing or identifying sweet potato/tapioca starch based on nitrogen stable isotope Download PDFInfo
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Abstract
The invention discloses a method for analyzing or identifying sweet potato/tapioca starch based on nitrogen stable isotope, and belongs to the technical field of food detection. The method for analyzing sweet potato/tapioca starch based on nitrogen stable isotope of the invention specifically comprises the following steps: grinding sweet potato/tapioca starch, mixing the ground sweet potato/tapioca starch with anhydrous sodium carbonate, and adding water for dissolution; then carrying out ultrasonic treatment, centrifuging, taking supernatant, and concentrating in vacuum; adding ethanol into the concentrated liquid, shaking, standing, centrifuging, collecting precipitate, washing, oven drying, grinding, and pulverizing to obtain extract; the extract is measured by a nitrogen stable isotope ratio mass spectrometer. The method is simple to operate, does not influence the measurement result of the nitrogen stable isotope due to the introduction of an external nitrogen source, and effectively solves the problem that the ratio of the nitrogen isotopes of sweet potato/tapioca starch cannot be measured by adopting a stable isotope ratio mass spectrometer.
Description
Technical Field
The invention relates to a method for analyzing or identifying sweet potato/tapioca starch based on nitrogen stable isotope, belonging to the technical field of food detection.
Background
The nitrogen stable isotope analysis technology is to carry out the analysis of different isotopes (delta) of nitrogen element 15 Stable isotope ratio of N nitrogen, i.e., the ratio of nitrogen-15 to nitrogen-14) was analyzed and studied. The reason why plants produce nitrogen stable isotopes depends mainly on two aspects, on the one hand on the absorption of the foreign nitrogen source by the plants and on the other hand on the conversion of the nitrogen element in the organism.
Sweet potato and cassava are rhizome crops rich in starch, the starch is a common food processing raw material, and the phenomenon that the cassava starch replaces sweet potato starch to produce food is common because the cassava starch is much cheaper than sweet potato starch. Cassava and sweet potatoes belong to the Euphorbiaceae and Convolvulaceae respectively, and the main production areas of the two types of crops have larger temperature difference, the cassava is planted in the area with higher temperature, and the sweet potato is planted in the area with proper temperature; and delta 15 N has positive correlation with temperature, so sweet potato starch and tapioca starch delta 15 There is a significant difference in N.
The stable isotope technology is widely applied to identification and analysis of livestock meat such as cattle and sheep, aquatic products such as river crabs and fish, grain and oil crops such as rice and olive oil, vegetables and fruits such as durian and potato. Stable isotopes can be used for analyzing isotopes of five elements including carbon, nitrogen, hydrogen, oxygen and sulfur, but the carbon isotopes of sweet potatoes and cassava are relatively close and difficult to distinguish, and the three isotopes of hydrogen, oxygen and sulfur have poorer stability than the nitrogen isotopes. The stability of the on-machine test of the nitrogen isotopes is good, and the applicant's earlier research finds that the difference of the nitrogen isotopes of sweet potato and cassava is relatively large, and the degree of distinction is good, but when the analysis of the nitrogen isotope ratio is directly carried out on sweet potato starch or cassava starch, no signal is generated, and the nitrogen isotope ratio cannot be effectively used for analyzing or identifying sweet potato starch and cassava starch; there is currently no method for distinguishing nitrogen stable isotope tests with respect to sweet potato starch or tapioca starch.
Disclosure of Invention
In order to solve the problems, the invention provides a method for analyzing or identifying sweet potato starch/tapioca starch based on nitrogen stable isotope. In the early-stage research, the signals of the nitrogen stable isotope ratio of sweet potato starch and tapioca starch cannot be obtained through a direct test mode.
Therefore, the invention carries out pretreatment on the sweet potato/tapioca starch, namely, the sweet potato/tapioca starch is added with anhydrous sodium carbonate, water-soluble under specific conditions and ultrasonic extraction are carried out, and the specific washing mode is adopted, so that the extract in the starch is finally extracted to achieve the purpose of enriching and concentrating nitrogen elements, and the problem that the sweet potato/tapioca starch cannot directly adopt a stable isotope ratio mass spectrometer to measure the nitrogen isotope ratio is effectively solved.
The invention aims to provide a method for analyzing sweet potato/tapioca starch based on nitrogen stable isotope, which comprises the following steps:
(1) Grinding sweet potato/tapioca starch, mixing the ground sweet potato/tapioca starch with anhydrous sodium carbonate, and adding water for dissolution; then carrying out ultrasonic treatment, centrifuging, taking supernatant, and concentrating in vacuum;
(2) Adding ethanol into the concentrated liquid in the step (1), shaking, standing, centrifuging, collecting precipitate, washing, oven drying, grinding and pulverizing to obtain extract;
(3) And (3) measuring the extract obtained in the step (2) by using a nitrogen stable isotope ratio mass spectrometer.
In one embodiment, the grinding of sweet potato/tapioca starch in step (1) refers to grinding to 55-65 mesh with a quartz mortar.
In one embodiment, the mass ratio of sweet potato/tapioca starch to anhydrous sodium carbonate in step (1) is 1-2:0.009; preferably 1:0.009.
In one embodiment, the water of step (1) is added in a ratio of sweet potato/tapioca starch: 20-30:3; mL/g.
In one embodiment, the sonication conditions of step (1) are: the power is 100-500W, and the time is 1-2 h; preferably ultrasonic power 300W for a period of 2 hours.
In one embodiment, the centrifugation conditions of step (1): 4000-6000 r/min for 10-20 min.
In one embodiment, the vacuum concentration in step (1) is performed by transferring supernatant from the centrifuge tube to another centrifuge tube after centrifugation, and then placing the supernatant into the centrifuge tube for vacuum concentration at 40-50 ℃.
In one embodiment, the ethanol in step (2) is 90% -95% ethanol by volume.
In one embodiment, the shaking-up and standing time in step (2) is 2-5 hours.
In one embodiment, the condition of the re-centrifugation in the step (2) is 3000 to 4000r/min, 15 to 25min.
In one embodiment, the washing in step (2) means washing with 75% ethanol by volume or washing with 95% ethanol by volume and then washing with 75% ethanol by volume.
In one embodiment, the drying temperature of step (2) is: 40-60 ℃.
In one embodiment, the grinding in step (2) is to a particle size of 90 to 110 mesh.
In one embodiment, the detection conditions for a nitrogen stable isotope ratio mass spectrometer are: n mode, oxidation tube temperature 980 ℃, carrier gas flow rate 180mL/min, column temperature 50 ℃, O 2 Flow rate175mL/min, oxygen injection time of 3s, reference gas flow rate of 70mL/min.
In one embodiment, the mass spectrometry conditions for a nitrogen stable isotope ratio mass spectrometer are: the ion source voltage is 3.05kV, the carrier gas is high-purity helium, and the pressure is 300kPa; the pressure of the reference gas nitrogen is 0.4MPa; vacuum degree 1.5X10 -6 mBa Faraday cup detector receives 28, 29, and 30 target ions; reference gas N using caffeine standard 2 Calibration is performed and the nitrogen isotope ratio of the sample is determined.
In one embodiment, when using a nitrogen stable isotope ratio mass spectrometer for detection, a sample to be detected (extract) needs to be wrapped by a tin cup and placed into an automatic sampler, and the mass of the extract is 5-7 mg.
In one embodiment, the ratio of the nitrogen isotopes of the sweet potato starch is 2-5 per mill; the ratio of the nitrogen isotope measurement of the cassava starch is in the range of 6-11 per mill.
The second object of the invention is to provide a method for identifying sweet potato starch and tapioca starch based on nitrogen stable isotopes, comprising the following steps:
the method for analyzing the sweet potato/tapioca starch based on the nitrogen stable isotope is adopted to process a sample to be detected, nitrogen isotope detection is carried out, and whether the ratio of the sweet potato starch to the tapioca starch is 2-5 per mill or 6-11 per mill is judged according to the measured nitrogen isotope ratio is judged to identify the sample to be detected.
The invention has the beneficial effects that:
(1) According to the invention, anhydrous sodium carbonate and ethanol are added, and specific conditions are controlled, so that a target substance in the starch is extracted to achieve the purpose of enriching and concentrating nitrogen elements, and the problem that the ratio of nitrogen isotopes cannot be directly measured by adopting a stable isotope ratio mass spectrometer by sweet potato/tapioca starch is solved;
(2) The preparation process of the invention has the advantages of less reagent, simple operation, no introduction of external nitrogen source and no influence on the determination result of nitrogen stable isotope.
Drawings
FIG. 1 is a graph of comparative example 1 for directly determining nitrogen isotope ratio of sweet potato starch;
FIG. 2 is a graph showing the nitrogen isotope ratio of sweet potato starch measured in example 1;
FIG. 3 is a graph showing the nitrogen isotope ratio of sweet potato starch measured in comparative example 2;
FIG. 4 is a graph showing the nitrogen isotope ratio of sweet potato starch measured in comparative example 3;
FIG. 5 is a graph showing the nitrogen isotope ratio of sweet potato starch measured in comparative example 4;
FIG. 6 is a graph showing nitrogen isotope ratio of sweet potato starch measured by water extraction of 10ml in comparative example 5;
FIG. 7 is a graph showing nitrogen isotope ratio of sweet potato starch measured by 45ml water extraction in comparative example 5;
FIG. 8 is a graph showing the nitrogen isotope ratio of sweet potato starch measured without ethanol washing in example 4;
FIG. 9 is a graph showing the nitrogen isotope ratio of sweet potato starch determined by the secondary washing in example 4.
Detailed Description
The following description of the preferred embodiments of the present invention is provided for better illustration of the invention, and should not be construed as limiting the invention.
Example 1
A method for detecting sweet potato starch based on nitrogen stable isotopes, the method comprising pretreatment and testing of nitrogen isotope ratios;
wherein, the pretreatment includes:
(1) The prepared sweet potato starch was ground to 60 mesh with a quartz mortar, and 3g of sweet potato starch and 0.027g of anhydrous sodium carbonate (Na 2 CO 3 ) Adding the mixture into a 50ml centrifuge tube, injecting 20ml of ultrapure water into the centrifuge tube by using a water purifier, and shaking the mixture uniformly to fully dissolve the ultrapure water;
(2) Placing the centrifuge tube into an ultrasonic cleaner, setting the ultrasonic time to be 2 hours, setting the ultrasonic power to be 300W, and performing ultrasonic treatment; after the completion, putting the centrifuge tube into a centrifuge, centrifuging for 15 minutes at 5000r/min, taking supernatant, transferring the supernatant into another centrifuge tube, and then putting the centrifuge tube into a condition of 40 ℃ for vacuum concentration; concentrating the liquid to 3mL, taking out, adding 30mL of 95% ethanol into the tube, shaking uniformly, standing for 2.5h, and standing for precipitation;
(3) Putting the sample precipitated in the step (2) into a centrifuge, centrifuging at 3500r/min for 20 minutes, pouring out supernatant after centrifugation, reserving precipitate, washing the precipitate once by using 75% ethanol, and finally putting into a drying oven at 40 ℃ for drying, and grinding to 100-mesh granularity to obtain the sample;
testing nitrogen isotope ratio: weighing 5 mg, packaging the prepared sample into a tin cup, placing the tin cup into an instrument for detection, and recording data, wherein the result is shown in figure 2;
test conditions: the gas flow rate of the elemental analyzer-gas isotope mass spectrometer was adjusted to Carrier:180mL/min; oxygen:175mL/min, oxygen injection time 3s; reference:70mL/min, opening an ion source, and setting the furnace temperature (oxidation tube temperature) to 980 ℃;
isotope mass spectrometry conditions: the ion source voltage is 3.05kV; the carrier gas is high-purity helium with the pressure of 300kPa; the pressure of the reference gas nitrogen is 0.4Mpa; vacuum degree 1.5X10 -6 mBa the faraday cup detector receives target ions of mass numbers 28, 29 and 30. The nitrogen reference gas used was calibrated with a caffeine nitrogen isotope standard (delta 15N-1.00%v.v-PDE) and used as a quality control sample for the test procedure.
As can be seen from the results of fig. 1 and 2, the nitrogen isotope ratio of the sweet potato starch is directly tested to have no response signal (fig. 1). After the treatment of example 1, a stable response signal of nitrogen isotope ratio can be obtained, and the signal is generally considered to be in a normal range from 1000mV to 10000 mV; delta 15N v.s Air N 2 The per mill ratio is 3.080.
Example 2
14 parts of sweet potato starch of different producing areas and varieties are respectively taken, the nitrogen isotope ratio of the sweet potato starch is measured by referring to the method of the example 1, and the results are shown in the table 1:
TABLE 1 Nitrogen isotope ratio of sweet potato starch
As shown in the results of Table 1, the ratio of the nitrogen isotopes of the sweet potato starch is 2-5%.
Example 3
8 parts of tapioca starch of different producing places and varieties are taken respectively, the nitrogen isotope ratio of the tapioca starch is measured by referring to the detection method of the example 1, and the measurement results are shown in the table 2:
TABLE 2 Nitrogen isotope ratio of cassava starch
As shown in the results of Table 2, the ratio of the tapioca starch measured by using nitrogen isotopes is in the range of 6 to 11 per mill.
Example 4
The difference from example 1 is that the number of times of ethanol washing in step (3) was adjusted so that no ethanol washing and no secondary washing (95% ethanol first and 75% ethanol second) were used, respectively, and other parameters and conditions were the same as those in example 1.
As shown in FIG. 8 (without ethanol washing) and FIG. 9 (with secondary washing), the extracted nitrogen isotope ratio signals obtained without ethanol washing and secondary washing were both in the range of 1000mV-10000mV, but the nitrogen isotope ratio δ15N.s Air N without ethanol washing 2 The permillage reaches 3.913; the nitrogen isotope ratio of the secondary wash and the primary wash of example 1 was relatively low, δ15N v.s Air N 2 Per mill of 2.464 and 3.080, respectively; it can be seen that the extract obtained from the primary and secondary washes more easily distinguishes sweet potato starch from tapioca starch.
Example 5
A method for identifying sweet potato starch and tapioca starch based on nitrogen stable isotopes, the method comprising the following steps:
the pretreatment method of example 1 is adopted to treat the sample to be detected, and nitrogen isotope detection is carried out, and the sample to be detected is identified according to the nitrogen isotope ratio range of the sweet potato starch of example 2 and the tapioca starch of example 3 (the ratio range of the sweet potato starch nitrogen isotopes is 2-5 per mill, and the ratio range of the tapioca starch nitrogen isotopes is 6-11 per mill).
Comparative example 1
The difference from example 1 is that the sweet potato starch is not pretreated, the nitrogen isotope ratio test is directly carried out, the test parameters and conditions are the same as those of example 1, the test results are shown in fig. 1, and the signal response of the spectrum nitrogen-free isotope ratio can be seen.
Comparative example 2
The difference from example 1 is only that the mass ratio of starch to anhydrous sodium carbonate in step (1) was adjusted to 6g:0.027g, and other parameters and conditions were the same as in example 1.
As a result of the test, as shown in FIG. 3, it can be seen that the extract of example 1 has a stronger response signal to the nitrogen isotope ratio signal than that of comparative example 3, and the difference between the nitrogen isotope ratios measured in example 1 and comparative example 3 is also larger, delta 15N v.s Air N in example 1 2 3.080 per mill, delta 15N v.s Air N in comparative example 3 2 6.620 per mill; it can be seen that the obtained extract has the strongest nitrogen isotope ratio signal and the most proper ratio when the mass ratio of starch to anhydrous sodium carbonate is 3g to 0.027 g.
Comparative example 3
The only difference from example 1 is that the extraction solvent in the adjustment step (3) is chloroform: n-butanol (4:1, v:v), other parameters and conditions were the same as in example 1.
The test results are shown in fig. 4, and it can be seen that chloroform: the n-butanol (4:1, v:v) can obtain extract with nitrogen isotope ratio signal of 300-400mV, which can not reach 1000mV-10000mV, and can not be used for analysis of sweet potato starch.
Comparative example 4
The difference from example 1 is that the ultrasonic time in the adjustment step (2) is 1h and 1.5h respectively, and other parameters and conditions are the same as those in example 1.
The test result shows that the ultrasonic wave is carried out for 1h, the extract has almost no signal when the nitrogen isotope ratio is tested, and the signal when the nitrogen isotope ratio is tested is very weak when the ultrasonic wave time is 1.5h, as shown in figure 5; only in the ultrasonic treatment for 2 hours, the extract has a stronger signal ratio in the measurement of the nitrogen isotope ratio.
Comparative example 5
The difference from example 1 was that the amount of water added in step (1) was adjusted to 10mL and 45mL, respectively, and other parameters and conditions were the same as those in example 1.
The results are shown in FIG. 6 (10 mL) and FIG. 7 (45 mL); as is clear from the results of FIGS. 6 and 7, when the amount of water added was 10mL and 45mL, the nitrogen isotope ratio signal of the obtained extract was also weak, and it was not possible to reach the range of 1000mV to 10000 mV.
The above examples are not intended to limit the scope of the invention nor the order of execution of the steps described. The present invention is obviously modified by a person skilled in the art in combination with the prior common general knowledge, and falls within the scope of protection defined by the claims of the present invention.
Claims (9)
1. A method for analyzing sweet potato/tapioca starch based on nitrogen stable isotope, which is characterized by comprising the following steps:
(1) Grinding sweet potato/tapioca starch, mixing the ground sweet potato/tapioca starch with anhydrous sodium carbonate, and adding water for dissolution; then carrying out ultrasonic treatment, centrifuging, taking supernatant, and concentrating in vacuum; the mass ratio of the sweet potato/tapioca starch to the anhydrous sodium carbonate is 1-2:0.009;
(2) Adding ethanol into the concentrated liquid in the step (1), shaking, standing, centrifuging, collecting precipitate, washing, oven drying, grinding and pulverizing to obtain extract;
(3) And (3) measuring the extract obtained in the step (2) by using a nitrogen stable isotope ratio mass spectrometer.
2. The method of claim 1, wherein the water is added in the step (1) in a ratio of sweet potato/tapioca starch of: 20-30:3; mL/g.
3. The method of claim 1, wherein the sonication conditions of step (1) are: the power is 100-500W and the time is 1-2 h.
4. The method of claim 1, wherein the centrifugation conditions of step (1) are: 4000-6000 r/min for 10-20 min.
5. The method according to claim 1, wherein the washing in step (2) is performed once with a volume fraction of 75% ethanol or once with a volume fraction of 95% ethanol and then once with a volume fraction of 75% ethanol.
6. The method of claim 1, wherein the detection conditions of the nitrogen stable isotope ratio mass spectrometer are: n mode, oxidation tube temperature 980 ℃, carrier gas flow rate 180mL/min, column temperature 50 ℃, O 2 The flow rate was 175mL/min, the oxygen injection time was 3s, and the reference gas flow rate was 70mL/min.
7. The method of claim 1, wherein the mass spectrometry conditions of the nitrogen stable isotope ratio mass spectrometer are: vacuum degree of 1.5X10 -6 mBa, ion source voltage 3.05kV; n isotope corresponding characteristic substance N 2 The method comprises the steps of carrying out a first treatment on the surface of the Reference gas N using caffeine standard 2 Calibration is performed and the nitrogen isotope ratio of the sample is determined.
8. The method according to claim 1, wherein the ratio of nitrogen isotopes of the sweet potato starch is in the range of 2-5%o; the ratio of the nitrogen isotope measurement of the cassava starch is in the range of 6-11 per mill.
9. A method for identifying sweet potato starch and tapioca starch based on nitrogen stable isotopes, which is characterized by comprising the following steps:
the method for analyzing sweet potato/tapioca starch based on nitrogen stable isotopes according to any one of claims 1-8 is adopted to treat a sample to be detected, nitrogen isotope detection is carried out, and whether the ratio of the nitrogen isotopes of the sweet potato starch is 2-5 per mill or 6-11 per mill is judged according to the measured ratio of the nitrogen isotopes, so that the sample to be detected is identified.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105388206A (en) * | 2015-12-11 | 2016-03-09 | 宜宾五粮液股份有限公司 | Method for detecting starchy carbon stable isotope in wine brewing grains |
| KR20170053803A (en) * | 2015-11-06 | 2017-05-17 | 제주대학교 산학협력단 | Method for detecting or quantifying starch in processed meat foods |
| CN106841361A (en) * | 2016-12-16 | 2017-06-13 | 中国农业科学院农产品加工研究所 | Whether adulterated in a kind of discriminating tuber crops food the method for xenogenesis starch |
| JP2017133904A (en) * | 2016-01-27 | 2017-08-03 | 独立行政法人酒類総合研究所 | Method for determining existence of addition of citric acid in alcoholic drink |
| KR20170125300A (en) * | 2017-09-27 | 2017-11-14 | 건국대학교 산학협력단 | Method for identifying cultivation region of potato using isotope ratio and multivariate statistical analysis |
| KR20190048343A (en) * | 2017-10-31 | 2019-05-09 | 한국기초과학지원연구원 | Method for discriminating the geographical origin of pork using C, N and S |
| CN111474275A (en) * | 2020-04-29 | 2020-07-31 | 内蒙古自治区农牧业科学院 | Potato origin tracing method based on mineral elements and stable isotopes |
| CN115792018A (en) * | 2022-12-07 | 2023-03-14 | 广东省农业科学院作物研究所 | Method for determining content of 13 carotenoids in sweet potatoes |
-
2024
- 2024-01-31 CN CN202410129880.6A patent/CN117664689B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20170053803A (en) * | 2015-11-06 | 2017-05-17 | 제주대학교 산학협력단 | Method for detecting or quantifying starch in processed meat foods |
| CN105388206A (en) * | 2015-12-11 | 2016-03-09 | 宜宾五粮液股份有限公司 | Method for detecting starchy carbon stable isotope in wine brewing grains |
| JP2017133904A (en) * | 2016-01-27 | 2017-08-03 | 独立行政法人酒類総合研究所 | Method for determining existence of addition of citric acid in alcoholic drink |
| CN106841361A (en) * | 2016-12-16 | 2017-06-13 | 中国农业科学院农产品加工研究所 | Whether adulterated in a kind of discriminating tuber crops food the method for xenogenesis starch |
| KR20170125300A (en) * | 2017-09-27 | 2017-11-14 | 건국대학교 산학협력단 | Method for identifying cultivation region of potato using isotope ratio and multivariate statistical analysis |
| KR20190048343A (en) * | 2017-10-31 | 2019-05-09 | 한국기초과학지원연구원 | Method for discriminating the geographical origin of pork using C, N and S |
| CN111474275A (en) * | 2020-04-29 | 2020-07-31 | 内蒙古自治区农牧业科学院 | Potato origin tracing method based on mineral elements and stable isotopes |
| CN115792018A (en) * | 2022-12-07 | 2023-03-14 | 广东省农业科学院作物研究所 | Method for determining content of 13 carotenoids in sweet potatoes |
Non-Patent Citations (1)
| Title |
|---|
| 杨健;吴浩;吕朝耕;王升;张小波;杨光;郭兰萍;黄璐琦;: "基于稳定同位素的铁皮石斛产地识别研究", 中国中药杂志, no. 06, 15 January 2018 (2018-01-15) * |
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